Rare Diseases

SAVANNAH, GEORGIA — Current disease-modifying therapies for amyotrophic lateral sclerosis (ALS) don’t extend lifespans by much, but several drug options are available, nerve specialists learned.

The glutamate blocker riluzole (Rilutek), which became the first ALS drug to receive US Food and Drug Administration (FDA) approval in 1995, continues to be used, Michael D. Weiss, MD, professor of neurology at University of Washington School of Medicine, Seattle, said in a presentation at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.

Weiss highlighted a 2012 Cochrane Library review that examined research and found the drug is “reasonably safe” and prolongs median survival by about 2-3 months. “About 12% develop liver disease. It’s pretty rare that we stop the medicine due to liver toxicity.”
 

Earlier Treatment Could Pay Dividends

A recent study “suggests we might be able to get more bang for our buck from riluzole” by initiating treatment earlier, Weiss said.

Researchers tracked 4778 patients with ALS, including 3446 (72.1%) who took riluzole. Those who took the drug survived a median 2 extra months (22.6 vs 20.2 months; P < .001). The data suggested that delaying riluzole initiation by 1 year (from 6 months to 18 months after diagnosis) reduced the median survival by 1.9 months (from 40.1 to 38.2 months).

There’s “a relatively significant additional benefit” to earlier treatment, Weiss said, although patients will vary on whether they think it’s meaningful. As for limitations, “there’s no clear impact on disease progression, and there’s a need for periodic monitoring of liver function profile.” 

He added that there’s an out-of-pocket co-pay. “Even as a generic, it’s not that cheap. Depending on the source, it could cost anywhere from $1800 to $8400 a year.”
 

Edaravone Could Lack Relevant Benefit

No other ALS treatment appeared until 2017, when the FDA approved the novel antioxidant edaravone (Radicava). In 2022, the agency approved an oral suspension version, but a study published that year suggested there may not be a clinically relevant benefit.

The University of Washington, where Weiss works, offered the drug to 144 patients, according to an analysis. Eighty percent of the patients wanted it, but insurers refused to cover it for more than 20%. The average time to treatment with the drug was 28 days after patients said they wanted it.

That’s a “substantial delay,” Weiss said.

The cost is about $171,000 a year, he said, and assistance is limited for underinsured patients.*

Other Options

As Weiss noted, another drug, AMX0035 (Relyvrio), received FDA approval in 2022, but its manufacturer pulled it from the US/Canada market in April 2024 following poor phase 3 trial findings.

In 2023, the FDA approved another drug, the antisense oligonucleotide tofersen (Qalsody), in patients with ALS associated with a mutation in the superoxide dismutase 1 gene. According to the FDA, reductions in plasma neurofilament light concentration were “reasonably likely to predict a clinical benefit in patients.”

Only 1%-2% of patients with ALS fit the criteria to get the drug, Weiss said. He noted other limitations such as the cost ($180,000 a year), the need for lifelong monthly intrathecal injections, and serious neurological side effects in 7% of patients per a 2022 trial.

Weiss disclosed advisory board (Alexion, Ra [now UCB], argenx, Biogen, Mitsubishi Tanabe Pharma, Amylyx), data safety monitoring board (Sanofi, AI), consulting (Cytokinetics, CSL Behring), and speaker (Soleo) relationships.

*Correction, 10/23/2024: This story originally quoted Weiss as saying the maker of edaravone provides no assistance to underinsured patients. Weiss has clarified that he should have said this coverage is “limited.”

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA — Current disease-modifying therapies for amyotrophic lateral sclerosis (ALS) don’t extend lifespans by much, but several drug options are available, nerve specialists learned.

The glutamate blocker riluzole (Rilutek), which became the first ALS drug to receive US Food and Drug Administration (FDA) approval in 1995, continues to be used, Michael D. Weiss, MD, professor of neurology at University of Washington School of Medicine, Seattle, said in a presentation at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.

Weiss highlighted a 2012 Cochrane Library review that examined research and found the drug is “reasonably safe” and prolongs median survival by about 2-3 months. “About 12% develop liver disease. It’s pretty rare that we stop the medicine due to liver toxicity.”
 

Earlier Treatment Could Pay Dividends

A recent study “suggests we might be able to get more bang for our buck from riluzole” by initiating treatment earlier, Weiss said.

Researchers tracked 4778 patients with ALS, including 3446 (72.1%) who took riluzole. Those who took the drug survived a median 2 extra months (22.6 vs 20.2 months; P < .001). The data suggested that delaying riluzole initiation by 1 year (from 6 months to 18 months after diagnosis) reduced the median survival by 1.9 months (from 40.1 to 38.2 months).

There’s “a relatively significant additional benefit” to earlier treatment, Weiss said, although patients will vary on whether they think it’s meaningful. As for limitations, “there’s no clear impact on disease progression, and there’s a need for periodic monitoring of liver function profile.” 

He added that there’s an out-of-pocket co-pay. “Even as a generic, it’s not that cheap. Depending on the source, it could cost anywhere from $1800 to $8400 a year.”
 

Edaravone Could Lack Relevant Benefit

No other ALS treatment appeared until 2017, when the FDA approved the novel antioxidant edaravone (Radicava). In 2022, the agency approved an oral suspension version, but a study published that year suggested there may not be a clinically relevant benefit.

The University of Washington, where Weiss works, offered the drug to 144 patients, according to an analysis. Eighty percent of the patients wanted it, but insurers refused to cover it for more than 20%. The average time to treatment with the drug was 28 days after patients said they wanted it.

That’s a “substantial delay,” Weiss said.

The cost is about $171,000 a year, he said, and assistance is limited for underinsured patients.*

Other Options

As Weiss noted, another drug, AMX0035 (Relyvrio), received FDA approval in 2022, but its manufacturer pulled it from the US/Canada market in April 2024 following poor phase 3 trial findings.

In 2023, the FDA approved another drug, the antisense oligonucleotide tofersen (Qalsody), in patients with ALS associated with a mutation in the superoxide dismutase 1 gene. According to the FDA, reductions in plasma neurofilament light concentration were “reasonably likely to predict a clinical benefit in patients.”

Only 1%-2% of patients with ALS fit the criteria to get the drug, Weiss said. He noted other limitations such as the cost ($180,000 a year), the need for lifelong monthly intrathecal injections, and serious neurological side effects in 7% of patients per a 2022 trial.

Weiss disclosed advisory board (Alexion, Ra [now UCB], argenx, Biogen, Mitsubishi Tanabe Pharma, Amylyx), data safety monitoring board (Sanofi, AI), consulting (Cytokinetics, CSL Behring), and speaker (Soleo) relationships.

*Correction, 10/23/2024: This story originally quoted Weiss as saying the maker of edaravone provides no assistance to underinsured patients. Weiss has clarified that he should have said this coverage is “limited.”

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA — Current disease-modifying therapies for amyotrophic lateral sclerosis (ALS) don’t extend lifespans by much, but several drug options are available, nerve specialists learned.

The glutamate blocker riluzole (Rilutek), which became the first ALS drug to receive US Food and Drug Administration (FDA) approval in 1995, continues to be used, Michael D. Weiss, MD, professor of neurology at University of Washington School of Medicine, Seattle, said in a presentation at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.

Weiss highlighted a 2012 Cochrane Library review that examined research and found the drug is “reasonably safe” and prolongs median survival by about 2-3 months. “About 12% develop liver disease. It’s pretty rare that we stop the medicine due to liver toxicity.”
 

Earlier Treatment Could Pay Dividends

A recent study “suggests we might be able to get more bang for our buck from riluzole” by initiating treatment earlier, Weiss said.

Researchers tracked 4778 patients with ALS, including 3446 (72.1%) who took riluzole. Those who took the drug survived a median 2 extra months (22.6 vs 20.2 months; P < .001). The data suggested that delaying riluzole initiation by 1 year (from 6 months to 18 months after diagnosis) reduced the median survival by 1.9 months (from 40.1 to 38.2 months).

There’s “a relatively significant additional benefit” to earlier treatment, Weiss said, although patients will vary on whether they think it’s meaningful. As for limitations, “there’s no clear impact on disease progression, and there’s a need for periodic monitoring of liver function profile.” 

He added that there’s an out-of-pocket co-pay. “Even as a generic, it’s not that cheap. Depending on the source, it could cost anywhere from $1800 to $8400 a year.”
 

Edaravone Could Lack Relevant Benefit

No other ALS treatment appeared until 2017, when the FDA approved the novel antioxidant edaravone (Radicava). In 2022, the agency approved an oral suspension version, but a study published that year suggested there may not be a clinically relevant benefit.

The University of Washington, where Weiss works, offered the drug to 144 patients, according to an analysis. Eighty percent of the patients wanted it, but insurers refused to cover it for more than 20%. The average time to treatment with the drug was 28 days after patients said they wanted it.

That’s a “substantial delay,” Weiss said.

The cost is about $171,000 a year, he said, and assistance is limited for underinsured patients.*

Other Options

As Weiss noted, another drug, AMX0035 (Relyvrio), received FDA approval in 2022, but its manufacturer pulled it from the US/Canada market in April 2024 following poor phase 3 trial findings.

In 2023, the FDA approved another drug, the antisense oligonucleotide tofersen (Qalsody), in patients with ALS associated with a mutation in the superoxide dismutase 1 gene. According to the FDA, reductions in plasma neurofilament light concentration were “reasonably likely to predict a clinical benefit in patients.”

Only 1%-2% of patients with ALS fit the criteria to get the drug, Weiss said. He noted other limitations such as the cost ($180,000 a year), the need for lifelong monthly intrathecal injections, and serious neurological side effects in 7% of patients per a 2022 trial.

Weiss disclosed advisory board (Alexion, Ra [now UCB], argenx, Biogen, Mitsubishi Tanabe Pharma, Amylyx), data safety monitoring board (Sanofi, AI), consulting (Cytokinetics, CSL Behring), and speaker (Soleo) relationships.

*Correction, 10/23/2024: This story originally quoted Weiss as saying the maker of edaravone provides no assistance to underinsured patients. Weiss has clarified that he should have said this coverage is “limited.”

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA — One patient with autoimmune myasthenia gravis (MG) has a niece with the same diagnosis, and at least one of his other close relatives may have it too. Another patient with MG lost his father and brother to complications from the disease, while a surviving brother also has it. These two cases, reported at a meeting of nerve/muscle specialists, spotlight one of the mysteries of MG: What role does heredity play in this disorder?

“Clinical familial associations — when transmission appears to be vertical, from parent to offspring — suggest that there is much yet to learn about genetic bases for autoimmunity and how certain mutations could favor selection for specific immune disorders,” said Elena Shanina, MD, PhD, a neurology professor at the University of Texas Medical Branch, Galveston, in an interview. She and colleagues presented the two case reports at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.

As Shanina noted, MG is usually sporadic without a link to heredity. However, she said, research suggests that up to 7% of patients have MG in their family history.

“There are well-described genetic causes for congenital myasthenic syndromes, in which mutations occur in genes for neuromuscular junction (NMJ) proteins affecting NMJ function. However, much less is known about genetic associations to autoimmune MG,” she said.

“More than a decade ago, differences in HLA DQ haplotype-associated presentation of AChR alpha-chain peptides were suggested to suffice in producing MG, and specific HLA DQ susceptibility links were found predisposing to MG. More recent studies have tried to identify specific genes such as CTLA4 mutations that enhance autoimmunity and neuroinflammation.”
 

Two Cases

In one of the case reports, a 75-year-old White man with hereditary coagulopathy presented with myasthenic crisis in the setting of acute pulmonary embolism. Chronic symptoms included diplopia, ptosis, and proximal muscle weakness.

A niece of the patient has been diagnosed with MG and suffers from ocular symptoms. Meanwhile, an uncle has ptosis but no diagnosis yet, and a daughter has dermatomyositis. Like MG, dermatomyositis is an autoimmune disease that causes muscle weakness.

The patient, who’s CTLA4 negative, is faring well on eculizumab after failing standard therapies, Shanina said.

In the other case, a 67-year-old Hispanic man presented with diplopia, generalized fatigue, and weakness. Like the other patient, he was seropositive for acetylcholine receptor antibodies.

This patient lost his father and brother to complications from MG. Another brother, who’s still living, also has MG.

“The patient has minimal manifestation status with disease and is currently controlled using oral immunomodulatory therapies,” Shanina said. “He is also CTLA4 negative.”
 

Genetics and Environment May Each Play a Role

Shanina called for research exploring mutations and inheritance patterns in families with MG.

“If there are genetic causes that increase autoimmunity with specific propensity for certain immune diseases, correcting those mutations could fundamentally change how we treat — and prevent — at least some autoimmune diseases,” she said. “For example, if HLA linkage is directly involved in determining susceptibility to MG, and if the presence of a specific HLA locus allele is sufficient to produce disease, HLA gene editing could be a future therapy to prevent such diseases. Likewise, monoclonal antibodies that target products of genes that increase risk for autoimmunity might be able to reduce such risks without modifying the patient’s genome.”

Henry J. Kaminski, MD, professor of neurology at George Washington University, Washington, DC, is familiar with the report’s findings. In an interview, he noted that while genetic profiles can make MG more likely, “the situation is not like Huntington’s or Alzheimer’s where there is a strong genetic risk.” 

Instead, he said, there’s “a genetic risk coupled to some environmental stimulus that leads to the development of MG, which is true for many complex autoimmune conditions.” 

While he doesn’t think the two new case reports are especially noteworthy, Kaminski said “the ability to assess genetic risk factors across patients will elucidate understanding of MG. Personalized medicine choices will likely require understanding of genetic risks.”

While understanding MG in families is “always good to know from a research perspective,” there’s no reason to launch surveillance of relatives to see if they also have the disease, he said.

Also, Kaminski cautioned that it’s important to differentiate autoimmune MG from congenital myasthenia, an even more rare genetic disorder of neuromuscular transmission. “Congenital myasthenias will not improve with immune therapy, and patients will suffer complications for no reason,” he said. “A patient who is seronegative should be assessed for congenital myasthenia with the right clinical presentation. The condition would be more likely in patients with a family history of symptoms similar to MG. It may be symptomatic at birth, but patients may present in adulthood.”

Kaminski noted that his team is collecting saliva samples from patients with MuSK-MG, a rare MG subtype linked to more severe cases, for genetic testing and genome-wide association studies.

There was no study funding, and the authors have no disclosures. Kaminski is principal investigator of a rare disease network dedicated to MG.

A version of this article first appeared on Medscape.com.

SAVANNAH, GEORGIA — One patient with autoimmune myasthenia gravis (MG) has a niece with the same diagnosis, and at least one of his other close relatives may have it too. Another patient with MG lost his father and brother to complications from the disease, while a surviving brother also has it. These two cases, reported at a meeting of nerve/muscle specialists, spotlight one of the mysteries of MG: What role does heredity play in this disorder?

“Clinical familial associations — when transmission appears to be vertical, from parent to offspring — suggest that there is much yet to learn about genetic bases for autoimmunity and how certain mutations could favor selection for specific immune disorders,” said Elena Shanina, MD, PhD, a neurology professor at the University of Texas Medical Branch, Galveston, in an interview. She and colleagues presented the two case reports at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.

As Shanina noted, MG is usually sporadic without a link to heredity. However, she said, research suggests that up to 7% of patients have MG in their family history.

“There are well-described genetic causes for congenital myasthenic syndromes, in which mutations occur in genes for neuromuscular junction (NMJ) proteins affecting NMJ function. However, much less is known about genetic associations to autoimmune MG,” she said.

“More than a decade ago, differences in HLA DQ haplotype-associated presentation of AChR alpha-chain peptides were suggested to suffice in producing MG, and specific HLA DQ susceptibility links were found predisposing to MG. More recent studies have tried to identify specific genes such as CTLA4 mutations that enhance autoimmunity and neuroinflammation.”
 

Two Cases

In one of the case reports, a 75-year-old White man with hereditary coagulopathy presented with myasthenic crisis in the setting of acute pulmonary embolism. Chronic symptoms included diplopia, ptosis, and proximal muscle weakness.

A niece of the patient has been diagnosed with MG and suffers from ocular symptoms. Meanwhile, an uncle has ptosis but no diagnosis yet, and a daughter has dermatomyositis. Like MG, dermatomyositis is an autoimmune disease that causes muscle weakness.

The patient, who’s CTLA4 negative, is faring well on eculizumab after failing standard therapies, Shanina said.

In the other case, a 67-year-old Hispanic man presented with diplopia, generalized fatigue, and weakness. Like the other patient, he was seropositive for acetylcholine receptor antibodies.

This patient lost his father and brother to complications from MG. Another brother, who’s still living, also has MG.

“The patient has minimal manifestation status with disease and is currently controlled using oral immunomodulatory therapies,” Shanina said. “He is also CTLA4 negative.”
 

Genetics and Environment May Each Play a Role

Shanina called for research exploring mutations and inheritance patterns in families with MG.

“If there are genetic causes that increase autoimmunity with specific propensity for certain immune diseases, correcting those mutations could fundamentally change how we treat — and prevent — at least some autoimmune diseases,” she said. “For example, if HLA linkage is directly involved in determining susceptibility to MG, and if the presence of a specific HLA locus allele is sufficient to produce disease, HLA gene editing could be a future therapy to prevent such diseases. Likewise, monoclonal antibodies that target products of genes that increase risk for autoimmunity might be able to reduce such risks without modifying the patient’s genome.”

Henry J. Kaminski, MD, professor of neurology at George Washington University, Washington, DC, is familiar with the report’s findings. In an interview, he noted that while genetic profiles can make MG more likely, “the situation is not like Huntington’s or Alzheimer’s where there is a strong genetic risk.” 

Instead, he said, there’s “a genetic risk coupled to some environmental stimulus that leads to the development of MG, which is true for many complex autoimmune conditions.” 

While he doesn’t think the two new case reports are especially noteworthy, Kaminski said “the ability to assess genetic risk factors across patients will elucidate understanding of MG. Personalized medicine choices will likely require understanding of genetic risks.”

While understanding MG in families is “always good to know from a research perspective,” there’s no reason to launch surveillance of relatives to see if they also have the disease, he said.

Also, Kaminski cautioned that it’s important to differentiate autoimmune MG from congenital myasthenia, an even more rare genetic disorder of neuromuscular transmission. “Congenital myasthenias will not improve with immune therapy, and patients will suffer complications for no reason,” he said. “A patient who is seronegative should be assessed for congenital myasthenia with the right clinical presentation. The condition would be more likely in patients with a family history of symptoms similar to MG. It may be symptomatic at birth, but patients may present in adulthood.”

Kaminski noted that his team is collecting saliva samples from patients with MuSK-MG, a rare MG subtype linked to more severe cases, for genetic testing and genome-wide association studies.

There was no study funding, and the authors have no disclosures. Kaminski is principal investigator of a rare disease network dedicated to MG.

A version of this article first appeared on Medscape.com.

SAVANNAH, GEORGIA — One patient with autoimmune myasthenia gravis (MG) has a niece with the same diagnosis, and at least one of his other close relatives may have it too. Another patient with MG lost his father and brother to complications from the disease, while a surviving brother also has it. These two cases, reported at a meeting of nerve/muscle specialists, spotlight one of the mysteries of MG: What role does heredity play in this disorder?

“Clinical familial associations — when transmission appears to be vertical, from parent to offspring — suggest that there is much yet to learn about genetic bases for autoimmunity and how certain mutations could favor selection for specific immune disorders,” said Elena Shanina, MD, PhD, a neurology professor at the University of Texas Medical Branch, Galveston, in an interview. She and colleagues presented the two case reports at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.

As Shanina noted, MG is usually sporadic without a link to heredity. However, she said, research suggests that up to 7% of patients have MG in their family history.

“There are well-described genetic causes for congenital myasthenic syndromes, in which mutations occur in genes for neuromuscular junction (NMJ) proteins affecting NMJ function. However, much less is known about genetic associations to autoimmune MG,” she said.

“More than a decade ago, differences in HLA DQ haplotype-associated presentation of AChR alpha-chain peptides were suggested to suffice in producing MG, and specific HLA DQ susceptibility links were found predisposing to MG. More recent studies have tried to identify specific genes such as CTLA4 mutations that enhance autoimmunity and neuroinflammation.”
 

Two Cases

In one of the case reports, a 75-year-old White man with hereditary coagulopathy presented with myasthenic crisis in the setting of acute pulmonary embolism. Chronic symptoms included diplopia, ptosis, and proximal muscle weakness.

A niece of the patient has been diagnosed with MG and suffers from ocular symptoms. Meanwhile, an uncle has ptosis but no diagnosis yet, and a daughter has dermatomyositis. Like MG, dermatomyositis is an autoimmune disease that causes muscle weakness.

The patient, who’s CTLA4 negative, is faring well on eculizumab after failing standard therapies, Shanina said.

In the other case, a 67-year-old Hispanic man presented with diplopia, generalized fatigue, and weakness. Like the other patient, he was seropositive for acetylcholine receptor antibodies.

This patient lost his father and brother to complications from MG. Another brother, who’s still living, also has MG.

“The patient has minimal manifestation status with disease and is currently controlled using oral immunomodulatory therapies,” Shanina said. “He is also CTLA4 negative.”
 

Genetics and Environment May Each Play a Role

Shanina called for research exploring mutations and inheritance patterns in families with MG.

“If there are genetic causes that increase autoimmunity with specific propensity for certain immune diseases, correcting those mutations could fundamentally change how we treat — and prevent — at least some autoimmune diseases,” she said. “For example, if HLA linkage is directly involved in determining susceptibility to MG, and if the presence of a specific HLA locus allele is sufficient to produce disease, HLA gene editing could be a future therapy to prevent such diseases. Likewise, monoclonal antibodies that target products of genes that increase risk for autoimmunity might be able to reduce such risks without modifying the patient’s genome.”

Henry J. Kaminski, MD, professor of neurology at George Washington University, Washington, DC, is familiar with the report’s findings. In an interview, he noted that while genetic profiles can make MG more likely, “the situation is not like Huntington’s or Alzheimer’s where there is a strong genetic risk.” 

Instead, he said, there’s “a genetic risk coupled to some environmental stimulus that leads to the development of MG, which is true for many complex autoimmune conditions.” 

While he doesn’t think the two new case reports are especially noteworthy, Kaminski said “the ability to assess genetic risk factors across patients will elucidate understanding of MG. Personalized medicine choices will likely require understanding of genetic risks.”

While understanding MG in families is “always good to know from a research perspective,” there’s no reason to launch surveillance of relatives to see if they also have the disease, he said.

Also, Kaminski cautioned that it’s important to differentiate autoimmune MG from congenital myasthenia, an even more rare genetic disorder of neuromuscular transmission. “Congenital myasthenias will not improve with immune therapy, and patients will suffer complications for no reason,” he said. “A patient who is seronegative should be assessed for congenital myasthenia with the right clinical presentation. The condition would be more likely in patients with a family history of symptoms similar to MG. It may be symptomatic at birth, but patients may present in adulthood.”

Kaminski noted that his team is collecting saliva samples from patients with MuSK-MG, a rare MG subtype linked to more severe cases, for genetic testing and genome-wide association studies.

There was no study funding, and the authors have no disclosures. Kaminski is principal investigator of a rare disease network dedicated to MG.

A version of this article first appeared on Medscape.com.

SAVANNAH, GEORGIA — There’s no medical treatment for Charcot-Marie-Tooth (CMT) disease, a debilitating neurologic disorder that’s both progressive and incurable. But now, nerve specialists learned, new potential treatments are moving closer to clinical trials.

Genetic-based therapies for CMT are currently in preclinical research phases, and an experimental small-molecule drug has reached phase 3 in humans, neurologists told an audience at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024. But the neurologists also noted challenges, such as determining the best way to track disease progression — which can be slow — and the need to recruit high numbers of patients for trials.
 

A Common Genetic Neuromuscular Disorder

As Mario Saporta, MD, PhD, MBA, of the University of Miami, Coral Gables, Florida, explained, CMT is the most common genetic neuromuscular disorder, affecting 1 in 2500 people or about 130,000-150,000 in the United States. “Typically, it’s a length-dependent neuropathy, where your longest nerves would be affected earlier and more severely. That’s why we see foot deformities, inverted champagne bottle legs, and hand atrophy.”

Most patients with CMT in the United States have type 1A, which is linked to duplication of the PMP22 gene. All types lead to axonal degeneration, which appears to be the main cause of functional disability, Saporta said. “Patients become weaker and then progress with time, following the degree of axonal generation that they have.”

As many as 150 genes may eventually be deemed to cause CMT. The high number of genetically different forms makes diagnosis and genetic therapy difficult, he said, but that’s just part of the picture. Variations among mutations mean there’s “probably actually over 1000 different diseases” within CMT from a biologic perspective.
 

Genetic Therapy

In regard to genetic treatment, Bipasha Mukherjee-Clavin, MD, PhD, of Johns Hopkins University School of Medicine, Baltimore, Maryland, said a key factor is whether the patient’s form of CMT is passed on in an autosomal dominant or autosomal recessive manner.

“Autosomal dominant conditions are typically caused by gain of function mutations. So that means the goal of our genetic therapeutic would be to reduce expression of the mutated gene,” she said. “In contrast, autosomal recessive conditions are caused by loss-of-function mutations, which means the goal of our genetic therapeutic would be to replace the mutated gene with a normal, wild-type copy.”

A tool like CRISPR could be used to directly edit the part of the genome with a CMT-causing mutation or a viral vector could deliver a healthy, wild-type copy of a gene, she said. These approaches are both being tested.

Another approach is to reduce expression at the RNA level. “RNA therapeutics are FDA [Food and Drug Administration]–approved for other neuromuscular indications, and you may well be using some of these in your own clinical practice,” she said.

Currently, about seven different projects are in the works on the RNA therapeutics front in CMT, she said, including six focusing on type 1A. Mukherjee-Clavin believes that this subtype is a “great” target because it’s so common, affecting an estimated 1 in 5000 people.

“You actually have enough patients to power a clinical trial,” she said. Also, “it’s a homogeneous population, both in terms of the genetics and in terms of the clinical presentation.”
 

Preclinical Treatment Approaches

However, there are challenges. Drug delivery to Schwann cells, which insulate axons, is difficult, she said. “The other problem is that we want to avoid overly silencing PMP22 because that runs the theoretical risk of causing a different condition, HNPP [hereditary neuropathy with liability to pressure palsies]. HNPP is caused by deletions of PMP22, so we want to avoid that situation.”

Mukherjee-Clavin highlighted two RNA therapeutic products that she expects to move from preclinical to clinical research soon.

One is TVR110 by Armatus Bio, a microRNA intrathecal injection product, which aims to reduce PMP22 overexpression. “It targets basically reduces PMP22 mRNA expression and then normalizes the amount of PMP22 protein that is ultimately generated,” she said.

The other therapy, a small interfering RNA intravenous product delivered to Schwann cells, is being developed by DTx Pharma/Novartis.

Outside of the RNA arena, “there are a number of other programs that are in the preclinical phases that I think will be moving through this pipeline,” Mukherjee-Clavin said. “We’ll see if some of these enter first-in-human clinical trials.”

Meanwhile, Saporta highlighted small-molecule strategies that target a subtype of CMT called sorbitol dehydrogenase (SORD) deficiency that’s caused by mutations in the SORD gene. He noted that Applied Therapeutics is testing an investigational drug called govorestat (AT-007) in 56 patients in a double-blind, randomized, placebo-controlled phase 3 registrational study. The company recently reported that interim 12-month results are promising.

Saporta disclosed consulting for DTx Pharma/Novartis, Applied Therapeutics, and Pharnext. Mukherjee-Clavin had no disclosures.

A version of this article first appeared on Medscape.com.

SAVANNAH, GEORGIA — There’s no medical treatment for Charcot-Marie-Tooth (CMT) disease, a debilitating neurologic disorder that’s both progressive and incurable. But now, nerve specialists learned, new potential treatments are moving closer to clinical trials.

Genetic-based therapies for CMT are currently in preclinical research phases, and an experimental small-molecule drug has reached phase 3 in humans, neurologists told an audience at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024. But the neurologists also noted challenges, such as determining the best way to track disease progression — which can be slow — and the need to recruit high numbers of patients for trials.
 

A Common Genetic Neuromuscular Disorder

As Mario Saporta, MD, PhD, MBA, of the University of Miami, Coral Gables, Florida, explained, CMT is the most common genetic neuromuscular disorder, affecting 1 in 2500 people or about 130,000-150,000 in the United States. “Typically, it’s a length-dependent neuropathy, where your longest nerves would be affected earlier and more severely. That’s why we see foot deformities, inverted champagne bottle legs, and hand atrophy.”

Most patients with CMT in the United States have type 1A, which is linked to duplication of the PMP22 gene. All types lead to axonal degeneration, which appears to be the main cause of functional disability, Saporta said. “Patients become weaker and then progress with time, following the degree of axonal generation that they have.”

As many as 150 genes may eventually be deemed to cause CMT. The high number of genetically different forms makes diagnosis and genetic therapy difficult, he said, but that’s just part of the picture. Variations among mutations mean there’s “probably actually over 1000 different diseases” within CMT from a biologic perspective.
 

Genetic Therapy

In regard to genetic treatment, Bipasha Mukherjee-Clavin, MD, PhD, of Johns Hopkins University School of Medicine, Baltimore, Maryland, said a key factor is whether the patient’s form of CMT is passed on in an autosomal dominant or autosomal recessive manner.

“Autosomal dominant conditions are typically caused by gain of function mutations. So that means the goal of our genetic therapeutic would be to reduce expression of the mutated gene,” she said. “In contrast, autosomal recessive conditions are caused by loss-of-function mutations, which means the goal of our genetic therapeutic would be to replace the mutated gene with a normal, wild-type copy.”

A tool like CRISPR could be used to directly edit the part of the genome with a CMT-causing mutation or a viral vector could deliver a healthy, wild-type copy of a gene, she said. These approaches are both being tested.

Another approach is to reduce expression at the RNA level. “RNA therapeutics are FDA [Food and Drug Administration]–approved for other neuromuscular indications, and you may well be using some of these in your own clinical practice,” she said.

Currently, about seven different projects are in the works on the RNA therapeutics front in CMT, she said, including six focusing on type 1A. Mukherjee-Clavin believes that this subtype is a “great” target because it’s so common, affecting an estimated 1 in 5000 people.

“You actually have enough patients to power a clinical trial,” she said. Also, “it’s a homogeneous population, both in terms of the genetics and in terms of the clinical presentation.”
 

Preclinical Treatment Approaches

However, there are challenges. Drug delivery to Schwann cells, which insulate axons, is difficult, she said. “The other problem is that we want to avoid overly silencing PMP22 because that runs the theoretical risk of causing a different condition, HNPP [hereditary neuropathy with liability to pressure palsies]. HNPP is caused by deletions of PMP22, so we want to avoid that situation.”

Mukherjee-Clavin highlighted two RNA therapeutic products that she expects to move from preclinical to clinical research soon.

One is TVR110 by Armatus Bio, a microRNA intrathecal injection product, which aims to reduce PMP22 overexpression. “It targets basically reduces PMP22 mRNA expression and then normalizes the amount of PMP22 protein that is ultimately generated,” she said.

The other therapy, a small interfering RNA intravenous product delivered to Schwann cells, is being developed by DTx Pharma/Novartis.

Outside of the RNA arena, “there are a number of other programs that are in the preclinical phases that I think will be moving through this pipeline,” Mukherjee-Clavin said. “We’ll see if some of these enter first-in-human clinical trials.”

Meanwhile, Saporta highlighted small-molecule strategies that target a subtype of CMT called sorbitol dehydrogenase (SORD) deficiency that’s caused by mutations in the SORD gene. He noted that Applied Therapeutics is testing an investigational drug called govorestat (AT-007) in 56 patients in a double-blind, randomized, placebo-controlled phase 3 registrational study. The company recently reported that interim 12-month results are promising.

Saporta disclosed consulting for DTx Pharma/Novartis, Applied Therapeutics, and Pharnext. Mukherjee-Clavin had no disclosures.

A version of this article first appeared on Medscape.com.

SAVANNAH, GEORGIA — There’s no medical treatment for Charcot-Marie-Tooth (CMT) disease, a debilitating neurologic disorder that’s both progressive and incurable. But now, nerve specialists learned, new potential treatments are moving closer to clinical trials.

Genetic-based therapies for CMT are currently in preclinical research phases, and an experimental small-molecule drug has reached phase 3 in humans, neurologists told an audience at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024. But the neurologists also noted challenges, such as determining the best way to track disease progression — which can be slow — and the need to recruit high numbers of patients for trials.
 

A Common Genetic Neuromuscular Disorder

As Mario Saporta, MD, PhD, MBA, of the University of Miami, Coral Gables, Florida, explained, CMT is the most common genetic neuromuscular disorder, affecting 1 in 2500 people or about 130,000-150,000 in the United States. “Typically, it’s a length-dependent neuropathy, where your longest nerves would be affected earlier and more severely. That’s why we see foot deformities, inverted champagne bottle legs, and hand atrophy.”

Most patients with CMT in the United States have type 1A, which is linked to duplication of the PMP22 gene. All types lead to axonal degeneration, which appears to be the main cause of functional disability, Saporta said. “Patients become weaker and then progress with time, following the degree of axonal generation that they have.”

As many as 150 genes may eventually be deemed to cause CMT. The high number of genetically different forms makes diagnosis and genetic therapy difficult, he said, but that’s just part of the picture. Variations among mutations mean there’s “probably actually over 1000 different diseases” within CMT from a biologic perspective.
 

Genetic Therapy

In regard to genetic treatment, Bipasha Mukherjee-Clavin, MD, PhD, of Johns Hopkins University School of Medicine, Baltimore, Maryland, said a key factor is whether the patient’s form of CMT is passed on in an autosomal dominant or autosomal recessive manner.

“Autosomal dominant conditions are typically caused by gain of function mutations. So that means the goal of our genetic therapeutic would be to reduce expression of the mutated gene,” she said. “In contrast, autosomal recessive conditions are caused by loss-of-function mutations, which means the goal of our genetic therapeutic would be to replace the mutated gene with a normal, wild-type copy.”

A tool like CRISPR could be used to directly edit the part of the genome with a CMT-causing mutation or a viral vector could deliver a healthy, wild-type copy of a gene, she said. These approaches are both being tested.

Another approach is to reduce expression at the RNA level. “RNA therapeutics are FDA [Food and Drug Administration]–approved for other neuromuscular indications, and you may well be using some of these in your own clinical practice,” she said.

Currently, about seven different projects are in the works on the RNA therapeutics front in CMT, she said, including six focusing on type 1A. Mukherjee-Clavin believes that this subtype is a “great” target because it’s so common, affecting an estimated 1 in 5000 people.

“You actually have enough patients to power a clinical trial,” she said. Also, “it’s a homogeneous population, both in terms of the genetics and in terms of the clinical presentation.”
 

Preclinical Treatment Approaches

However, there are challenges. Drug delivery to Schwann cells, which insulate axons, is difficult, she said. “The other problem is that we want to avoid overly silencing PMP22 because that runs the theoretical risk of causing a different condition, HNPP [hereditary neuropathy with liability to pressure palsies]. HNPP is caused by deletions of PMP22, so we want to avoid that situation.”

Mukherjee-Clavin highlighted two RNA therapeutic products that she expects to move from preclinical to clinical research soon.

One is TVR110 by Armatus Bio, a microRNA intrathecal injection product, which aims to reduce PMP22 overexpression. “It targets basically reduces PMP22 mRNA expression and then normalizes the amount of PMP22 protein that is ultimately generated,” she said.

The other therapy, a small interfering RNA intravenous product delivered to Schwann cells, is being developed by DTx Pharma/Novartis.

Outside of the RNA arena, “there are a number of other programs that are in the preclinical phases that I think will be moving through this pipeline,” Mukherjee-Clavin said. “We’ll see if some of these enter first-in-human clinical trials.”

Meanwhile, Saporta highlighted small-molecule strategies that target a subtype of CMT called sorbitol dehydrogenase (SORD) deficiency that’s caused by mutations in the SORD gene. He noted that Applied Therapeutics is testing an investigational drug called govorestat (AT-007) in 56 patients in a double-blind, randomized, placebo-controlled phase 3 registrational study. The company recently reported that interim 12-month results are promising.

Saporta disclosed consulting for DTx Pharma/Novartis, Applied Therapeutics, and Pharnext. Mukherjee-Clavin had no disclosures.

A version of this article first appeared on Medscape.com.

SAVANNAH, GEORGIA – The investigational monoclonal antibody nipocalimab (Johnson & Johnson) is associated with significant improvement in patients with generalized myasthenia gravis (gMG) over a 24-week period, according to topline results from the phase 3 VIVACITY-MG3 study.

The VIVACITY-MG3 trial is the first registrational study of a neonatal fragment crystallizable receptor (FcRn) blocker to show sustained efficacy through 6 months of fixed schedule dosing.

Lead investigator Tuan Vu, MD, professor of neurology at the University of South Florida in Tampa, presented the findings at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024. 
 

Autoantibody Depletion

FcRN plays a crucial role in the transport of immunoglobulin G. Blocking it can reduce circulating immunoglobulin G antibodies, including pathogenic gMG autoantibodies. 

The double-blind, placebo-controlled trial included 196 adults with a broad range of seropositive gMG – who account for approximately 95% of the gMG patient population – and 42 seronegative patients.

The mean age was 52 years, 92% were female, and 63% were White. The mean disease duration was about 8 years. Among seropositive patients, 87.6% were acetylcholine receptor autoantibody-positive (AChR+), 10.5% were muscle-specific kinase autoantibody-positive (MuSK+), and 2% were low-density lipoprotein receptor-related protein 4 antibody positive.

They were randomly assigned 1:1 to receive either nipocalimab IV plus standard of care, or placebo plus standard of care for 24 weeks. A total of 87 patients in the nipocalimab arm and 82 in the placebo arm completed the study.

The primary efficacy endpoint was the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Participants treated with nipocalimab demonstrated a statistically significant improvement of 4.70 points from baseline, compared to the 3.25-point improvement in those treated with placebo (P =.002). 
 

Clinically Meaningful Changes?

“For someone living with gMG, a 1 to 2-point improvement on MG-ADL may be the difference between normal eating and frequent choking on food, or shortness of breath at rest and being on a ventilator,” the drug’s manufacturer noted in a release. 

Secondary endpoints were also better in the nipocalimab group, compared with participants on placebo. Specifically, on the 13-item clinician assessed Quantitative Myasthenia Gravis disease severity score, patients who received nipocalimab had an average reduction of 4.86 points from baseline compared to a reduction of 2.05 points in the placebo arm (P <.001). 

Similarly, MG-ADL response (defined as ≥ 2-point improvement from baseline) was significantly greater in the nipocalimab versus placebo arms (68.8% vs 52.6%; P =.021).

Subgroup analysis revealed similar results for the different types of seropositive patients, but there was no statistically significant difference in results for seronegative patients treated with nipocalimab versus placebo.

“The drug was pretty well tolerated and there was little difference, other than more patients with muscle spasm in the nipocalimab group (12.2% vs 3.1%),” said Vu. 

In addition, peripheral edema occurred in 11.2% of the nipocalimab group and none of the placebo-treated patients. Cholesterol levels were also higher in the nipocalimab arm, but there were no cardiac side effects, he added.
 

Encouraging Findings

Commenting on the findings, Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, was encouraged.

“It’s a phase 3 trial, it’s positive, which is great, so it’ll be another drug on the market, another option for our patients,” she said. However, she cautioned, “their placebo arm did better than most placebos, so I think the delta is not as robust, but it was still statistically significant.” 

Goyal noted that, if approved, nipocalimab will be the third FcRn inhibitor in the MG field, preceded by efgartigimod (Vyvgart), which is approved for AChR antibody-positive disease, and rozanolixizumab-noli (Rystiggo) which is approved for both for AChR and MUSK antibody positive disease. 

“Its target of action is similar to the two drugs that are already on the market, but one thing that is unique about nipocalimab is that it is continuous dosing versus the other two medications that are given cyclically,” she said. 

“The reason that’s an upside, is that with cyclical dosing, patients have a return of symptoms. We treat, they get better, and then they get worse. That’s very disconcerting to patients. So, they want to be treated continuously.”

Additionally, she said there are some early data suggesting its safety in pregnancy.

Vu disclosed he is the USF Site Principal Investigator for MG clinical trials sponsored by Alexion/ AstraZeneca Rare Disease, Amgen, argenx, Cartesian Therapeutics, COUR Pharmaceuticals, Dianthus Therapeutics, Immunovant, Johnson & Johnson, NMD Pharmaceuticals, Regeneron Pharmaceuticals, and UCB, and has served as a speaker for Alexion/AstraZeneca Rare Disease, argenx, and CSL Behring. He performs consulting work for Alexion/AstraZeneca Rare Disease, argenx, Dianthus Therapeutics, ImmunAbs, and UCB. Goyal disclosed consultant, advisory or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Janssen. 
 

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA – The investigational monoclonal antibody nipocalimab (Johnson & Johnson) is associated with significant improvement in patients with generalized myasthenia gravis (gMG) over a 24-week period, according to topline results from the phase 3 VIVACITY-MG3 study.

The VIVACITY-MG3 trial is the first registrational study of a neonatal fragment crystallizable receptor (FcRn) blocker to show sustained efficacy through 6 months of fixed schedule dosing.

Lead investigator Tuan Vu, MD, professor of neurology at the University of South Florida in Tampa, presented the findings at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024. 
 

Autoantibody Depletion

FcRN plays a crucial role in the transport of immunoglobulin G. Blocking it can reduce circulating immunoglobulin G antibodies, including pathogenic gMG autoantibodies. 

The double-blind, placebo-controlled trial included 196 adults with a broad range of seropositive gMG – who account for approximately 95% of the gMG patient population – and 42 seronegative patients.

The mean age was 52 years, 92% were female, and 63% were White. The mean disease duration was about 8 years. Among seropositive patients, 87.6% were acetylcholine receptor autoantibody-positive (AChR+), 10.5% were muscle-specific kinase autoantibody-positive (MuSK+), and 2% were low-density lipoprotein receptor-related protein 4 antibody positive.

They were randomly assigned 1:1 to receive either nipocalimab IV plus standard of care, or placebo plus standard of care for 24 weeks. A total of 87 patients in the nipocalimab arm and 82 in the placebo arm completed the study.

The primary efficacy endpoint was the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Participants treated with nipocalimab demonstrated a statistically significant improvement of 4.70 points from baseline, compared to the 3.25-point improvement in those treated with placebo (P =.002). 
 

Clinically Meaningful Changes?

“For someone living with gMG, a 1 to 2-point improvement on MG-ADL may be the difference between normal eating and frequent choking on food, or shortness of breath at rest and being on a ventilator,” the drug’s manufacturer noted in a release. 

Secondary endpoints were also better in the nipocalimab group, compared with participants on placebo. Specifically, on the 13-item clinician assessed Quantitative Myasthenia Gravis disease severity score, patients who received nipocalimab had an average reduction of 4.86 points from baseline compared to a reduction of 2.05 points in the placebo arm (P <.001). 

Similarly, MG-ADL response (defined as ≥ 2-point improvement from baseline) was significantly greater in the nipocalimab versus placebo arms (68.8% vs 52.6%; P =.021).

Subgroup analysis revealed similar results for the different types of seropositive patients, but there was no statistically significant difference in results for seronegative patients treated with nipocalimab versus placebo.

“The drug was pretty well tolerated and there was little difference, other than more patients with muscle spasm in the nipocalimab group (12.2% vs 3.1%),” said Vu. 

In addition, peripheral edema occurred in 11.2% of the nipocalimab group and none of the placebo-treated patients. Cholesterol levels were also higher in the nipocalimab arm, but there were no cardiac side effects, he added.
 

Encouraging Findings

Commenting on the findings, Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, was encouraged.

“It’s a phase 3 trial, it’s positive, which is great, so it’ll be another drug on the market, another option for our patients,” she said. However, she cautioned, “their placebo arm did better than most placebos, so I think the delta is not as robust, but it was still statistically significant.” 

Goyal noted that, if approved, nipocalimab will be the third FcRn inhibitor in the MG field, preceded by efgartigimod (Vyvgart), which is approved for AChR antibody-positive disease, and rozanolixizumab-noli (Rystiggo) which is approved for both for AChR and MUSK antibody positive disease. 

“Its target of action is similar to the two drugs that are already on the market, but one thing that is unique about nipocalimab is that it is continuous dosing versus the other two medications that are given cyclically,” she said. 

“The reason that’s an upside, is that with cyclical dosing, patients have a return of symptoms. We treat, they get better, and then they get worse. That’s very disconcerting to patients. So, they want to be treated continuously.”

Additionally, she said there are some early data suggesting its safety in pregnancy.

Vu disclosed he is the USF Site Principal Investigator for MG clinical trials sponsored by Alexion/ AstraZeneca Rare Disease, Amgen, argenx, Cartesian Therapeutics, COUR Pharmaceuticals, Dianthus Therapeutics, Immunovant, Johnson & Johnson, NMD Pharmaceuticals, Regeneron Pharmaceuticals, and UCB, and has served as a speaker for Alexion/AstraZeneca Rare Disease, argenx, and CSL Behring. He performs consulting work for Alexion/AstraZeneca Rare Disease, argenx, Dianthus Therapeutics, ImmunAbs, and UCB. Goyal disclosed consultant, advisory or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Janssen. 
 

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA – The investigational monoclonal antibody nipocalimab (Johnson & Johnson) is associated with significant improvement in patients with generalized myasthenia gravis (gMG) over a 24-week period, according to topline results from the phase 3 VIVACITY-MG3 study.

The VIVACITY-MG3 trial is the first registrational study of a neonatal fragment crystallizable receptor (FcRn) blocker to show sustained efficacy through 6 months of fixed schedule dosing.

Lead investigator Tuan Vu, MD, professor of neurology at the University of South Florida in Tampa, presented the findings at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024. 
 

Autoantibody Depletion

FcRN plays a crucial role in the transport of immunoglobulin G. Blocking it can reduce circulating immunoglobulin G antibodies, including pathogenic gMG autoantibodies. 

The double-blind, placebo-controlled trial included 196 adults with a broad range of seropositive gMG – who account for approximately 95% of the gMG patient population – and 42 seronegative patients.

The mean age was 52 years, 92% were female, and 63% were White. The mean disease duration was about 8 years. Among seropositive patients, 87.6% were acetylcholine receptor autoantibody-positive (AChR+), 10.5% were muscle-specific kinase autoantibody-positive (MuSK+), and 2% were low-density lipoprotein receptor-related protein 4 antibody positive.

They were randomly assigned 1:1 to receive either nipocalimab IV plus standard of care, or placebo plus standard of care for 24 weeks. A total of 87 patients in the nipocalimab arm and 82 in the placebo arm completed the study.

The primary efficacy endpoint was the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Participants treated with nipocalimab demonstrated a statistically significant improvement of 4.70 points from baseline, compared to the 3.25-point improvement in those treated with placebo (P =.002). 
 

Clinically Meaningful Changes?

“For someone living with gMG, a 1 to 2-point improvement on MG-ADL may be the difference between normal eating and frequent choking on food, or shortness of breath at rest and being on a ventilator,” the drug’s manufacturer noted in a release. 

Secondary endpoints were also better in the nipocalimab group, compared with participants on placebo. Specifically, on the 13-item clinician assessed Quantitative Myasthenia Gravis disease severity score, patients who received nipocalimab had an average reduction of 4.86 points from baseline compared to a reduction of 2.05 points in the placebo arm (P <.001). 

Similarly, MG-ADL response (defined as ≥ 2-point improvement from baseline) was significantly greater in the nipocalimab versus placebo arms (68.8% vs 52.6%; P =.021).

Subgroup analysis revealed similar results for the different types of seropositive patients, but there was no statistically significant difference in results for seronegative patients treated with nipocalimab versus placebo.

“The drug was pretty well tolerated and there was little difference, other than more patients with muscle spasm in the nipocalimab group (12.2% vs 3.1%),” said Vu. 

In addition, peripheral edema occurred in 11.2% of the nipocalimab group and none of the placebo-treated patients. Cholesterol levels were also higher in the nipocalimab arm, but there were no cardiac side effects, he added.
 

Encouraging Findings

Commenting on the findings, Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, was encouraged.

“It’s a phase 3 trial, it’s positive, which is great, so it’ll be another drug on the market, another option for our patients,” she said. However, she cautioned, “their placebo arm did better than most placebos, so I think the delta is not as robust, but it was still statistically significant.” 

Goyal noted that, if approved, nipocalimab will be the third FcRn inhibitor in the MG field, preceded by efgartigimod (Vyvgart), which is approved for AChR antibody-positive disease, and rozanolixizumab-noli (Rystiggo) which is approved for both for AChR and MUSK antibody positive disease. 

“Its target of action is similar to the two drugs that are already on the market, but one thing that is unique about nipocalimab is that it is continuous dosing versus the other two medications that are given cyclically,” she said. 

“The reason that’s an upside, is that with cyclical dosing, patients have a return of symptoms. We treat, they get better, and then they get worse. That’s very disconcerting to patients. So, they want to be treated continuously.”

Additionally, she said there are some early data suggesting its safety in pregnancy.

Vu disclosed he is the USF Site Principal Investigator for MG clinical trials sponsored by Alexion/ AstraZeneca Rare Disease, Amgen, argenx, Cartesian Therapeutics, COUR Pharmaceuticals, Dianthus Therapeutics, Immunovant, Johnson & Johnson, NMD Pharmaceuticals, Regeneron Pharmaceuticals, and UCB, and has served as a speaker for Alexion/AstraZeneca Rare Disease, argenx, and CSL Behring. He performs consulting work for Alexion/AstraZeneca Rare Disease, argenx, Dianthus Therapeutics, ImmunAbs, and UCB. Goyal disclosed consultant, advisory or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Janssen. 
 

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA — Inebilizumab, a first-in-class anti-CD19 B-cell depleting agent, demonstrated both safety and superior efficacy compared with placebo in patients with seropositive generalized myasthenia gravis (gMG), new phase 3 data showed.

“Based on these results, we have demonstrated that targeting B cells, including the antibody-secreting cells, is beneficial, and there is likely a role for this kind of therapeutic strategy for patients with myasthenia gravis,” said senior investigator Richard Nowak, MD.

The findings were published and presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
 

Largest Cohort of Muscle-Specific Kinase (MuSK) Antibody–Positive Disease

The Myasthenia Gravis INebilizumab Trial study enrolled 238 participants, 60.8% women, mean age 47.5 years, from 79 sites in 18 countries. The participants were divided into two cohorts: 190 acetylcholine receptor (AChR) autoantibody–positive patients and 48 MuSK autoantibody–positive patients.

“This is the largest enrolled cohort of MuSK antibody–positive disease in a placebo-controlled trial to date,” said Nowak, director of the Yale Myasthenia Gravis Clinic and associate professor of neurology at Yale School of Medicine, in New Haven, Connecticut.

Both groups had similar gMG duration (mean 6.7 and 5.2 years for AChR+ and MuSK+ patients, respectively) and disease severity based on Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) baseline score. In addition, more than 80% of participants were on a prednisone equivalent dose greater than 5 mg daily at study entry.

Participants were randomly assigned to receive intravenous (IV) inebilizumab or IV placebo for 52 weeks (AChR+ group) or 26 weeks (MuSK+ group). In addition, study participants who were taking corticosteroids were tapered down starting at week 4 to prednisone 5 mg per day by week 24.

The trial met its primary endpoint, with a statistically significant change from baseline in MG-ADL and with a reduction of 4.2 points for inebilizumab versus 2.2 for placebo (P < .0001) at week 26 for the combined study population.

“You can see that the trend is actually going toward separation of the two groups after week 8 in the combined population,” said Nowak. Key secondary endpoints also showed statistically significant and clinically meaningful change from baseline compared with placebo.

This included a statistically significant change in QMG score inebilizumab compared with placebo for the combined population, a reduction of 4.8 versus 2.3 points, respectively, at week 26 (P = .0002).

In addition, both MG-ADL and QMG scores in the AChR+ subgroup were superior for inebilizumab versus placebo at week 26, with reductions of 4.2 versus 2.4, and 4.4 versus 2.0; P = .0015 and P = .0011, respectively.

In the MuSK+ subgroup, inebilizumab-treated patients had better MG-ADL scores than placebo-treated patients, with reductions of 3.9 versus 1.7 points, respectively, at week 26, although this difference did not meet statistical significance.

“There were no increased safety incidents in the inebilizumab-treated patients versus placebo, and a similar percentage of safety incidents in the AChR–positive and MuSK–positive groups. There were three deaths reported, all likely related to myasthenic crisis,” he said.

Nowak said that inebilizumab is “unique from the other currently FDA-approved medications for myasthenia gravis in that it’s targeting the upstream immunopathogenic mechanism of disease, specifically B cells — and B cells that are actually antibody-secreting cells.”

“It is targeting the factories of autoantibody production, whereas an FcRn antagonist, for example, is not targeting those factories but rather targeting what’s being produced — the immunoglobulins, IgGs in general,” he added.

Nowak said that what is particularly exciting about the drug is that the schedule is not very frequent. It begins with an initial IV infusion, followed by a second infusion 2 weeks later and a third infusion 6 months after that, so that patients are treated approximately every 6 months. This is in contrast to some other targeted therapies, where failing to address the underlying factors driving immunopathogenesis necessitates more regular and frequent medication administration.
 

New, Novel, Exciting

Commenting on the research, Neelam Goyal, MD, who chaired the session, said, “It’s definitely new, novel, interesting, exciting.”

Goyal, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, also noted that while B-cell depletion has shown some previous success in MG, it was with rituximab, a CD20 B-cell depleting agent.

She noted that unlike rituximab, which targets CD20, inebilizumab targets CD19, although both medications lead to B-cell depletion. Rituximab has proven effective for MUSK–positive MG, which accounts for approximately 5% of cases.

However, Goyal noted that the results for AChR–positive MG have been mixed — “the BeatMG trial was negative and the RINOMAX trial was positive. So, I think this is really interesting. It is exciting, and this drug is already on the market.”

She added that although inebilizumab is already US Food and Drug Administration–approved for the treatment of neuromyelitis optica, it still faces approval and indication hurdles for MG.

The future of this drug in the management algorithm for MG remains uncertain. Goyal noted that it’s “quite costly,” and although its benefits are evident — particularly for FcRn and complement inhibitors — some early data from chimeric antigen receptor T-cell therapy studies appear significantly more impressive.

Nowak disclosed research support from the National Institutes of Health, Genentech, Alexion Pharmaceuticals, argenx, Annexon Biosciences, Ra Pharmaceuticals (now UCB S.A.), the Myasthenia Gravis Foundation of America, Momenta Pharmaceuticals (now Janssen), Immunovant, Grifols, S.A., and Viela Bio, Horizon Therapeutics (now Amgen). Served as a consultant and advisor for Alexion Pharmaceuticals, argenx, Cabaletta Bio, Cour Pharmaceuticals, Ra Pharmaceuticals (now UCB S.A.), Immunovant, Momenta Pharmaceuticals (now Janssen), and Viela Bio (Horizon Therapeutics, now Amgen).

Goyal disclosed consultant, advisory, or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Amgen.
 

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA — Inebilizumab, a first-in-class anti-CD19 B-cell depleting agent, demonstrated both safety and superior efficacy compared with placebo in patients with seropositive generalized myasthenia gravis (gMG), new phase 3 data showed.

“Based on these results, we have demonstrated that targeting B cells, including the antibody-secreting cells, is beneficial, and there is likely a role for this kind of therapeutic strategy for patients with myasthenia gravis,” said senior investigator Richard Nowak, MD.

The findings were published and presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
 

Largest Cohort of Muscle-Specific Kinase (MuSK) Antibody–Positive Disease

The Myasthenia Gravis INebilizumab Trial study enrolled 238 participants, 60.8% women, mean age 47.5 years, from 79 sites in 18 countries. The participants were divided into two cohorts: 190 acetylcholine receptor (AChR) autoantibody–positive patients and 48 MuSK autoantibody–positive patients.

“This is the largest enrolled cohort of MuSK antibody–positive disease in a placebo-controlled trial to date,” said Nowak, director of the Yale Myasthenia Gravis Clinic and associate professor of neurology at Yale School of Medicine, in New Haven, Connecticut.

Both groups had similar gMG duration (mean 6.7 and 5.2 years for AChR+ and MuSK+ patients, respectively) and disease severity based on Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) baseline score. In addition, more than 80% of participants were on a prednisone equivalent dose greater than 5 mg daily at study entry.

Participants were randomly assigned to receive intravenous (IV) inebilizumab or IV placebo for 52 weeks (AChR+ group) or 26 weeks (MuSK+ group). In addition, study participants who were taking corticosteroids were tapered down starting at week 4 to prednisone 5 mg per day by week 24.

The trial met its primary endpoint, with a statistically significant change from baseline in MG-ADL and with a reduction of 4.2 points for inebilizumab versus 2.2 for placebo (P < .0001) at week 26 for the combined study population.

“You can see that the trend is actually going toward separation of the two groups after week 8 in the combined population,” said Nowak. Key secondary endpoints also showed statistically significant and clinically meaningful change from baseline compared with placebo.

This included a statistically significant change in QMG score inebilizumab compared with placebo for the combined population, a reduction of 4.8 versus 2.3 points, respectively, at week 26 (P = .0002).

In addition, both MG-ADL and QMG scores in the AChR+ subgroup were superior for inebilizumab versus placebo at week 26, with reductions of 4.2 versus 2.4, and 4.4 versus 2.0; P = .0015 and P = .0011, respectively.

In the MuSK+ subgroup, inebilizumab-treated patients had better MG-ADL scores than placebo-treated patients, with reductions of 3.9 versus 1.7 points, respectively, at week 26, although this difference did not meet statistical significance.

“There were no increased safety incidents in the inebilizumab-treated patients versus placebo, and a similar percentage of safety incidents in the AChR–positive and MuSK–positive groups. There were three deaths reported, all likely related to myasthenic crisis,” he said.

Nowak said that inebilizumab is “unique from the other currently FDA-approved medications for myasthenia gravis in that it’s targeting the upstream immunopathogenic mechanism of disease, specifically B cells — and B cells that are actually antibody-secreting cells.”

“It is targeting the factories of autoantibody production, whereas an FcRn antagonist, for example, is not targeting those factories but rather targeting what’s being produced — the immunoglobulins, IgGs in general,” he added.

Nowak said that what is particularly exciting about the drug is that the schedule is not very frequent. It begins with an initial IV infusion, followed by a second infusion 2 weeks later and a third infusion 6 months after that, so that patients are treated approximately every 6 months. This is in contrast to some other targeted therapies, where failing to address the underlying factors driving immunopathogenesis necessitates more regular and frequent medication administration.
 

New, Novel, Exciting

Commenting on the research, Neelam Goyal, MD, who chaired the session, said, “It’s definitely new, novel, interesting, exciting.”

Goyal, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, also noted that while B-cell depletion has shown some previous success in MG, it was with rituximab, a CD20 B-cell depleting agent.

She noted that unlike rituximab, which targets CD20, inebilizumab targets CD19, although both medications lead to B-cell depletion. Rituximab has proven effective for MUSK–positive MG, which accounts for approximately 5% of cases.

However, Goyal noted that the results for AChR–positive MG have been mixed — “the BeatMG trial was negative and the RINOMAX trial was positive. So, I think this is really interesting. It is exciting, and this drug is already on the market.”

She added that although inebilizumab is already US Food and Drug Administration–approved for the treatment of neuromyelitis optica, it still faces approval and indication hurdles for MG.

The future of this drug in the management algorithm for MG remains uncertain. Goyal noted that it’s “quite costly,” and although its benefits are evident — particularly for FcRn and complement inhibitors — some early data from chimeric antigen receptor T-cell therapy studies appear significantly more impressive.

Nowak disclosed research support from the National Institutes of Health, Genentech, Alexion Pharmaceuticals, argenx, Annexon Biosciences, Ra Pharmaceuticals (now UCB S.A.), the Myasthenia Gravis Foundation of America, Momenta Pharmaceuticals (now Janssen), Immunovant, Grifols, S.A., and Viela Bio, Horizon Therapeutics (now Amgen). Served as a consultant and advisor for Alexion Pharmaceuticals, argenx, Cabaletta Bio, Cour Pharmaceuticals, Ra Pharmaceuticals (now UCB S.A.), Immunovant, Momenta Pharmaceuticals (now Janssen), and Viela Bio (Horizon Therapeutics, now Amgen).

Goyal disclosed consultant, advisory, or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Amgen.
 

A version of this article appeared on Medscape.com.

SAVANNAH, GEORGIA — Inebilizumab, a first-in-class anti-CD19 B-cell depleting agent, demonstrated both safety and superior efficacy compared with placebo in patients with seropositive generalized myasthenia gravis (gMG), new phase 3 data showed.

“Based on these results, we have demonstrated that targeting B cells, including the antibody-secreting cells, is beneficial, and there is likely a role for this kind of therapeutic strategy for patients with myasthenia gravis,” said senior investigator Richard Nowak, MD.

The findings were published and presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
 

Largest Cohort of Muscle-Specific Kinase (MuSK) Antibody–Positive Disease

The Myasthenia Gravis INebilizumab Trial study enrolled 238 participants, 60.8% women, mean age 47.5 years, from 79 sites in 18 countries. The participants were divided into two cohorts: 190 acetylcholine receptor (AChR) autoantibody–positive patients and 48 MuSK autoantibody–positive patients.

“This is the largest enrolled cohort of MuSK antibody–positive disease in a placebo-controlled trial to date,” said Nowak, director of the Yale Myasthenia Gravis Clinic and associate professor of neurology at Yale School of Medicine, in New Haven, Connecticut.

Both groups had similar gMG duration (mean 6.7 and 5.2 years for AChR+ and MuSK+ patients, respectively) and disease severity based on Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) baseline score. In addition, more than 80% of participants were on a prednisone equivalent dose greater than 5 mg daily at study entry.

Participants were randomly assigned to receive intravenous (IV) inebilizumab or IV placebo for 52 weeks (AChR+ group) or 26 weeks (MuSK+ group). In addition, study participants who were taking corticosteroids were tapered down starting at week 4 to prednisone 5 mg per day by week 24.

The trial met its primary endpoint, with a statistically significant change from baseline in MG-ADL and with a reduction of 4.2 points for inebilizumab versus 2.2 for placebo (P < .0001) at week 26 for the combined study population.

“You can see that the trend is actually going toward separation of the two groups after week 8 in the combined population,” said Nowak. Key secondary endpoints also showed statistically significant and clinically meaningful change from baseline compared with placebo.

This included a statistically significant change in QMG score inebilizumab compared with placebo for the combined population, a reduction of 4.8 versus 2.3 points, respectively, at week 26 (P = .0002).

In addition, both MG-ADL and QMG scores in the AChR+ subgroup were superior for inebilizumab versus placebo at week 26, with reductions of 4.2 versus 2.4, and 4.4 versus 2.0; P = .0015 and P = .0011, respectively.

In the MuSK+ subgroup, inebilizumab-treated patients had better MG-ADL scores than placebo-treated patients, with reductions of 3.9 versus 1.7 points, respectively, at week 26, although this difference did not meet statistical significance.

“There were no increased safety incidents in the inebilizumab-treated patients versus placebo, and a similar percentage of safety incidents in the AChR–positive and MuSK–positive groups. There were three deaths reported, all likely related to myasthenic crisis,” he said.

Nowak said that inebilizumab is “unique from the other currently FDA-approved medications for myasthenia gravis in that it’s targeting the upstream immunopathogenic mechanism of disease, specifically B cells — and B cells that are actually antibody-secreting cells.”

“It is targeting the factories of autoantibody production, whereas an FcRn antagonist, for example, is not targeting those factories but rather targeting what’s being produced — the immunoglobulins, IgGs in general,” he added.

Nowak said that what is particularly exciting about the drug is that the schedule is not very frequent. It begins with an initial IV infusion, followed by a second infusion 2 weeks later and a third infusion 6 months after that, so that patients are treated approximately every 6 months. This is in contrast to some other targeted therapies, where failing to address the underlying factors driving immunopathogenesis necessitates more regular and frequent medication administration.
 

New, Novel, Exciting

Commenting on the research, Neelam Goyal, MD, who chaired the session, said, “It’s definitely new, novel, interesting, exciting.”

Goyal, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, also noted that while B-cell depletion has shown some previous success in MG, it was with rituximab, a CD20 B-cell depleting agent.

She noted that unlike rituximab, which targets CD20, inebilizumab targets CD19, although both medications lead to B-cell depletion. Rituximab has proven effective for MUSK–positive MG, which accounts for approximately 5% of cases.

However, Goyal noted that the results for AChR–positive MG have been mixed — “the BeatMG trial was negative and the RINOMAX trial was positive. So, I think this is really interesting. It is exciting, and this drug is already on the market.”

She added that although inebilizumab is already US Food and Drug Administration–approved for the treatment of neuromyelitis optica, it still faces approval and indication hurdles for MG.

The future of this drug in the management algorithm for MG remains uncertain. Goyal noted that it’s “quite costly,” and although its benefits are evident — particularly for FcRn and complement inhibitors — some early data from chimeric antigen receptor T-cell therapy studies appear significantly more impressive.

Nowak disclosed research support from the National Institutes of Health, Genentech, Alexion Pharmaceuticals, argenx, Annexon Biosciences, Ra Pharmaceuticals (now UCB S.A.), the Myasthenia Gravis Foundation of America, Momenta Pharmaceuticals (now Janssen), Immunovant, Grifols, S.A., and Viela Bio, Horizon Therapeutics (now Amgen). Served as a consultant and advisor for Alexion Pharmaceuticals, argenx, Cabaletta Bio, Cour Pharmaceuticals, Ra Pharmaceuticals (now UCB S.A.), Immunovant, Momenta Pharmaceuticals (now Janssen), and Viela Bio (Horizon Therapeutics, now Amgen).

Goyal disclosed consultant, advisory, or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Amgen.
 

A version of this article appeared on Medscape.com.

Editor’s Note
By Glenn S. Williams
In this year’s Rare Neurological Disease Special Report, we focus on rare neurological diseases that have new therapies that have been recently approved as well as conditions for which the treatment pipeline is robust.

A Note From NORD
By Pamela Gavin
Through NORD’s collaboration with Neurology Reviews, we share cutting-edge research and insights from leading medical experts, including specialists from the NORD Rare Disease Centers of Excellence network, about the latest advances in the treatment of rare neurological conditions.

Genetic Testing for ALS, Now a Standard, Creates a Path Toward Individualized Care
By Ted Bosworth
Overall, there is a sense of progress in ALS. The hope is that clinical research is reaching a tipping point where targeted treatments may offer hope to patients with ALS.

Myasthenia Gravis: Patient Choice, Cultural Change
By John Jesitus
Used appropriately, newer treatments for myasthenia gravis can provide dramatic results faster and more safely than broad immunosuppressants.

Promise for Disease-Modifying Therapies to Tame Huntington’s Disease
By Neil Osterweil
Much progress has been made in managing the symptoms of Huntington’s disease, but the real excitement lies in the development of disease-modifying drugs and genetic therapy.

Diagnosing and Managing Duchenne Muscular Dystrophy: Tips for Practicing Clinicians
By Batya Swift Yasgur, MA, LSW
Healthcare providers should be familiar enough with Duchenne muscular dystrophy to provide timely diagnosis and early intervention as well as practical and emotional support to the patient and family/caregivers.

Neuromyelitis Optica: Historically Misdiagnosed — Now Demands Prompt Treatment
By Kate Johnson
Rapid diagnosis and treatment of NMO “means potentially preventing future devastating neurologic injury.”

Untangling CIDP
By Jennie Smith
Though a preferred biomarker remains elusive, this difficult-to-diagnose neuropathy has seen important recent advances in diagnosis and treatment.

Newborn Screening Programs: What Do Clinicians Need to Know?
By Batya Swift Yasgur, MA, LSW
The goal of newborn screening is to identify babies with genetic disorders who otherwise have no obvious symptoms.

Balancing Act: Weighing the Pros and Cons of Genetic Testing in Rare Diseases
By Frieda Wiley
While genetic testing may offer great potential for providing answers to patients and clinicians seeking insight into a rare disorder, the technology holds some pros and cons that neurologists should be aware of.

Editor’s Note
By Glenn S. Williams
In this year’s Rare Neurological Disease Special Report, we focus on rare neurological diseases that have new therapies that have been recently approved as well as conditions for which the treatment pipeline is robust.

A Note From NORD
By Pamela Gavin
Through NORD’s collaboration with Neurology Reviews, we share cutting-edge research and insights from leading medical experts, including specialists from the NORD Rare Disease Centers of Excellence network, about the latest advances in the treatment of rare neurological conditions.

Genetic Testing for ALS, Now a Standard, Creates a Path Toward Individualized Care
By Ted Bosworth
Overall, there is a sense of progress in ALS. The hope is that clinical research is reaching a tipping point where targeted treatments may offer hope to patients with ALS.

Myasthenia Gravis: Patient Choice, Cultural Change
By John Jesitus
Used appropriately, newer treatments for myasthenia gravis can provide dramatic results faster and more safely than broad immunosuppressants.

Promise for Disease-Modifying Therapies to Tame Huntington’s Disease
By Neil Osterweil
Much progress has been made in managing the symptoms of Huntington’s disease, but the real excitement lies in the development of disease-modifying drugs and genetic therapy.

Diagnosing and Managing Duchenne Muscular Dystrophy: Tips for Practicing Clinicians
By Batya Swift Yasgur, MA, LSW
Healthcare providers should be familiar enough with Duchenne muscular dystrophy to provide timely diagnosis and early intervention as well as practical and emotional support to the patient and family/caregivers.

Neuromyelitis Optica: Historically Misdiagnosed — Now Demands Prompt Treatment
By Kate Johnson
Rapid diagnosis and treatment of NMO “means potentially preventing future devastating neurologic injury.”

Untangling CIDP
By Jennie Smith
Though a preferred biomarker remains elusive, this difficult-to-diagnose neuropathy has seen important recent advances in diagnosis and treatment.

Newborn Screening Programs: What Do Clinicians Need to Know?
By Batya Swift Yasgur, MA, LSW
The goal of newborn screening is to identify babies with genetic disorders who otherwise have no obvious symptoms.

Balancing Act: Weighing the Pros and Cons of Genetic Testing in Rare Diseases
By Frieda Wiley
While genetic testing may offer great potential for providing answers to patients and clinicians seeking insight into a rare disorder, the technology holds some pros and cons that neurologists should be aware of.

Editor’s Note
By Glenn S. Williams
In this year’s Rare Neurological Disease Special Report, we focus on rare neurological diseases that have new therapies that have been recently approved as well as conditions for which the treatment pipeline is robust.

A Note From NORD
By Pamela Gavin
Through NORD’s collaboration with Neurology Reviews, we share cutting-edge research and insights from leading medical experts, including specialists from the NORD Rare Disease Centers of Excellence network, about the latest advances in the treatment of rare neurological conditions.

Genetic Testing for ALS, Now a Standard, Creates a Path Toward Individualized Care
By Ted Bosworth
Overall, there is a sense of progress in ALS. The hope is that clinical research is reaching a tipping point where targeted treatments may offer hope to patients with ALS.

Myasthenia Gravis: Patient Choice, Cultural Change
By John Jesitus
Used appropriately, newer treatments for myasthenia gravis can provide dramatic results faster and more safely than broad immunosuppressants.

Promise for Disease-Modifying Therapies to Tame Huntington’s Disease
By Neil Osterweil
Much progress has been made in managing the symptoms of Huntington’s disease, but the real excitement lies in the development of disease-modifying drugs and genetic therapy.

Diagnosing and Managing Duchenne Muscular Dystrophy: Tips for Practicing Clinicians
By Batya Swift Yasgur, MA, LSW
Healthcare providers should be familiar enough with Duchenne muscular dystrophy to provide timely diagnosis and early intervention as well as practical and emotional support to the patient and family/caregivers.

Neuromyelitis Optica: Historically Misdiagnosed — Now Demands Prompt Treatment
By Kate Johnson
Rapid diagnosis and treatment of NMO “means potentially preventing future devastating neurologic injury.”

Untangling CIDP
By Jennie Smith
Though a preferred biomarker remains elusive, this difficult-to-diagnose neuropathy has seen important recent advances in diagnosis and treatment.

Newborn Screening Programs: What Do Clinicians Need to Know?
By Batya Swift Yasgur, MA, LSW
The goal of newborn screening is to identify babies with genetic disorders who otherwise have no obvious symptoms.

Balancing Act: Weighing the Pros and Cons of Genetic Testing in Rare Diseases
By Frieda Wiley
While genetic testing may offer great potential for providing answers to patients and clinicians seeking insight into a rare disorder, the technology holds some pros and cons that neurologists should be aware of.

Newly issued guidelines for cancer screening in patients with dermatomyositis had 100% sensitivity in a single institution’s cohort, though most of the cancers found would have been detected with standard cancer screenings recommended for the general population, according to a research letter published in JAMA Dermatology.

“These early results emphasize the continued need to refine risk assessment and cancer screening for patients with dermatomyositis while balancing resource use and outcomes,” concluded Caroline J. Stone and her colleagues at the Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia.

dermatology.cdlib.org/CC BY-SA 3.0/wikimedia

Patients with dermatomyositis have approximately a 4.7 times greater risk for cancer than those without it, according to a 2016 meta-analysis. Despite the well-established link between cancer and dermatomyositis, cancer in people with idiopathic inflammatory myopathies is commonly diagnosed at a later stage and is the leading cause of death in people with these conditions.
 

Guidelines First Presented in 2022 and Published in 2023

A wide variability in screening practices eventually led the International Myositis Assessment & Clinical Studies Group (IMACS) to present the first evidence-based and consensus-based guidelines for cancer screening of patients with idiopathic inflammatory myopathies, including those with dermatomyositis, at the 2022 annual meeting of the American College of Rheumatology and publish them in 2023 in Nature Reviews Rheumatology. The guidelines advise low-risk patients to undergo basic cancer screening with routine blood and urine studies, liver function tests, plain chest radiography, and age- and sex-appropriate cancer screening.

Intermediate- and high-risk patients are recommended to undergo enhanced screening that can include mammography, Pap tests, endoscopy/colonoscopy, pelvic and transvaginal ultrasonography, prostate-specific antigen or cancer antigen 125 blood tests, fecal occult blood tests, and CT of the neck, thorax, abdomen, and pelvis.

But because the guidelines are new, little evidence exists regarding their validation in real-world cohorts. Researchers, therefore, assessed the IMACS guidelines in 370 patients, aged 18-80 years, who visited the University of Pennsylvania rheumatology-dermatology specialty clinic between July 2008 and January 2024. All participants had dermatomyositis and at least 3 years of follow-up and were an average 48 years old. The vast majority were women (87%) and White participants (89%).

Most (68.6%) had myositis-specific autoantibody test results, one of the factors included in the guidelines for determining whether the patient should be classified as low, intermediate, or high risk. Other factors for risk stratification included myositis subtype, age at disease onset, and clinical features. About half (49.2%) had classic dermatomyositis, 42.4% had amyopathic dermatomyositis, 3.8% had juvenile dermatomyositis, 3.2% had hypomyopathic dermatomyositis, 0.8% had antisynthetase syndrome, and 0.5% had immune-mediated necrotizing myopathy.

Just over half the patients (54%) were classified as high risk, while 37.3% were classified as intermediate risk and 8.9% as low risk using the guidelines. Among the 18 patients (4.9%) with paraneoplastic dermatomyositis, 15 were classified as high risk and 3 as intermediate risk.

Of the patients diagnosed with cancer, 55% of cases were diagnosed about a year before their dermatomyositis diagnosis. In three patients, symptoms “suggestive of cancer at the time of dermatomyositis diagnosis, including lymphadenopathy and unexplained weight loss,” led to diagnostic testing that found an underlying cancer.

In the eight patients diagnosed with cancer after their dermatomyositis diagnosis, 75% of the cancers were identified during the first year of follow-up and 25% in the second year. Five were identified based on basic cancer screening and three on enhanced screening.

A total of 11 patients (3%) developed intravenous contrast allergies, and no other adverse events were reported to be associated with cancer screening, but the study was not designed to capture other types of adverse screening effects, such as cost, quality of life, or risk from radiation exposure.

The most common neoplasm identified was breast cancer, found in nine (50%) of the patients using mammography. Two patients had lung cancer identified with chest radiography and two had ovarian cancer identified with abdominal radiography and CT. The remaining five patients included one each with bladder cancer, papillary thyroid cancer, renal cell carcinoma, non-Hodgkin lymphoma, and adenocarcinoma with unknown primary.

The sensitivity of the guidelines in detecting cancer related to dermatomyositis was 100%, though the authors noted that the “IMACS risk-stratification scheme may overestimate cancer risk and encourage enhanced screening protocols of unclear benefit.” Most of the cancers found after dermatomyositis diagnosis were detected with routine age- and sex-related screening that already falls under basic cancer screening recommendations for the general population. Nonetheless, 90% of the participants fell into the intermediate- and high-risk groups, warranting a more comprehensive and costly enhanced screening protocol.
 

Will the Guidelines Lead to Overscreening? 

The 4.9% cancer prevalence is considerably lower than the typical 15%-25% prevalence among patients with dermatomyositis, but the findings, regardless, suggest the guidelines will lead to overscreening, wrote Andrea D. Maderal, MD, University of Miami Miller School of Medicine in Florida, and Alisa Femia, MD, New York University Grossman School of Medicine, New York City, in an accompanying editorial. Given that the median age in patients with cancer in the study was 58 years — 18 years older than the age cutoff for high-risk criteria — one way to refine the guidelines may be to increase the age for the high-risk category, they suggested.

“While these guidelines led to many ultimately unnecessary screening tests based on currently recommended designations of intermediate-risk and high-risk patients, these guidelines reflect a more conservative approach to screening than was previously performed,” Dr. Maderal and Dr. Femia wrote.

Jeff Gehlhausen, MD, PhD, an assistant professor of dermatology at Yale School of Medicine, New Haven, Connecticut, said he is not concerned about overscreening in patients, however, and is “very enthusiastic” about the findings.

“Patients are very anxious for good reason,” given the typical cancer prevalence of 25% in this population, he said in an interview. “I think therein lies the challenge — with that risk, what is ‘enough’ screening?” Yet this “incredibly impressive” study “provides real insights into the applicability of the IMACS screenings to our dermatomyositis management,” including relevance to his own patients. “Their findings are instructive for how to better evaluate these patients in a more mindful fashion,” he said, and they are particularly welcome, given how widely variable practice has historically been before the guidelines were issued.

“This question has been an outstanding one for decades, and nearly every doctor has a different answer,” Dr. Gehlhausen said. “The introduction of the guidelines alone are now much more actionable with this study, and that’s why it’s such an important one for our community.”

Benedict Wu, DO, PhD, director of Inpatient Dermatology and an assistant professor at Montefiore Einstein and a member of the Montefiore Einstein Comprehensive Cancer Center in New York City, similarly regarded the findings as reassuring, though he was surprised at the low prevalence of cancer in the patients.

“The most reassuring finding was that the detection of most malignancies was possible by using routine age- and sex-related screening combined with basic cancer screening,” Wu said in an interview. “Basic cancer screening can reduce costs while keeping patients safe.”

He also found it reassuring that all the paraneoplastic dermatomyositis was in intermediate- or high-risk patients, and while he does not see the IMACS guidelines as overestimating cancer risk, he does think “the risk stratification and recommended screening tests could be revised to be less ‘aggressive.’ ” 

The overall low rate of cancer in the group “calls into question the need for stringent and annual cancer screening,” he said. “In this large cohort of patients, the fact that malignancy was detected within 2 years of dermatomyositis diagnosis will help guide us with long-term screening recommendations.”

Despite the study’s small size and single-center design, the demographics of the patients nearly represents exactly what is found in the United States more broadly, Wu noted. He also drew attention to how many patients lacked the myositis antibody profile performed, and he agreed with the authors that more extensive and prospective studies need to be conducted. He also emphasized the need to keep in mind that “the primary goal of dermatomyositis management should focus on controlling/reducing the disease burden.”

The research was funded by the National Institutes of Health and the US Department of Veterans Affairs. The authors had no disclosures. Dr. Maderal reported personal fees from argenx. No disclosures were noted for Dr. Gehlhausen and Dr. Wu.

A version of this article appeared on Medscape.com.

Newly issued guidelines for cancer screening in patients with dermatomyositis had 100% sensitivity in a single institution’s cohort, though most of the cancers found would have been detected with standard cancer screenings recommended for the general population, according to a research letter published in JAMA Dermatology.

“These early results emphasize the continued need to refine risk assessment and cancer screening for patients with dermatomyositis while balancing resource use and outcomes,” concluded Caroline J. Stone and her colleagues at the Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia.

dermatology.cdlib.org/CC BY-SA 3.0/wikimedia

Patients with dermatomyositis have approximately a 4.7 times greater risk for cancer than those without it, according to a 2016 meta-analysis. Despite the well-established link between cancer and dermatomyositis, cancer in people with idiopathic inflammatory myopathies is commonly diagnosed at a later stage and is the leading cause of death in people with these conditions.
 

Guidelines First Presented in 2022 and Published in 2023

A wide variability in screening practices eventually led the International Myositis Assessment & Clinical Studies Group (IMACS) to present the first evidence-based and consensus-based guidelines for cancer screening of patients with idiopathic inflammatory myopathies, including those with dermatomyositis, at the 2022 annual meeting of the American College of Rheumatology and publish them in 2023 in Nature Reviews Rheumatology. The guidelines advise low-risk patients to undergo basic cancer screening with routine blood and urine studies, liver function tests, plain chest radiography, and age- and sex-appropriate cancer screening.

Intermediate- and high-risk patients are recommended to undergo enhanced screening that can include mammography, Pap tests, endoscopy/colonoscopy, pelvic and transvaginal ultrasonography, prostate-specific antigen or cancer antigen 125 blood tests, fecal occult blood tests, and CT of the neck, thorax, abdomen, and pelvis.

But because the guidelines are new, little evidence exists regarding their validation in real-world cohorts. Researchers, therefore, assessed the IMACS guidelines in 370 patients, aged 18-80 years, who visited the University of Pennsylvania rheumatology-dermatology specialty clinic between July 2008 and January 2024. All participants had dermatomyositis and at least 3 years of follow-up and were an average 48 years old. The vast majority were women (87%) and White participants (89%).

Most (68.6%) had myositis-specific autoantibody test results, one of the factors included in the guidelines for determining whether the patient should be classified as low, intermediate, or high risk. Other factors for risk stratification included myositis subtype, age at disease onset, and clinical features. About half (49.2%) had classic dermatomyositis, 42.4% had amyopathic dermatomyositis, 3.8% had juvenile dermatomyositis, 3.2% had hypomyopathic dermatomyositis, 0.8% had antisynthetase syndrome, and 0.5% had immune-mediated necrotizing myopathy.

Just over half the patients (54%) were classified as high risk, while 37.3% were classified as intermediate risk and 8.9% as low risk using the guidelines. Among the 18 patients (4.9%) with paraneoplastic dermatomyositis, 15 were classified as high risk and 3 as intermediate risk.

Of the patients diagnosed with cancer, 55% of cases were diagnosed about a year before their dermatomyositis diagnosis. In three patients, symptoms “suggestive of cancer at the time of dermatomyositis diagnosis, including lymphadenopathy and unexplained weight loss,” led to diagnostic testing that found an underlying cancer.

In the eight patients diagnosed with cancer after their dermatomyositis diagnosis, 75% of the cancers were identified during the first year of follow-up and 25% in the second year. Five were identified based on basic cancer screening and three on enhanced screening.

A total of 11 patients (3%) developed intravenous contrast allergies, and no other adverse events were reported to be associated with cancer screening, but the study was not designed to capture other types of adverse screening effects, such as cost, quality of life, or risk from radiation exposure.

The most common neoplasm identified was breast cancer, found in nine (50%) of the patients using mammography. Two patients had lung cancer identified with chest radiography and two had ovarian cancer identified with abdominal radiography and CT. The remaining five patients included one each with bladder cancer, papillary thyroid cancer, renal cell carcinoma, non-Hodgkin lymphoma, and adenocarcinoma with unknown primary.

The sensitivity of the guidelines in detecting cancer related to dermatomyositis was 100%, though the authors noted that the “IMACS risk-stratification scheme may overestimate cancer risk and encourage enhanced screening protocols of unclear benefit.” Most of the cancers found after dermatomyositis diagnosis were detected with routine age- and sex-related screening that already falls under basic cancer screening recommendations for the general population. Nonetheless, 90% of the participants fell into the intermediate- and high-risk groups, warranting a more comprehensive and costly enhanced screening protocol.
 

Will the Guidelines Lead to Overscreening? 

The 4.9% cancer prevalence is considerably lower than the typical 15%-25% prevalence among patients with dermatomyositis, but the findings, regardless, suggest the guidelines will lead to overscreening, wrote Andrea D. Maderal, MD, University of Miami Miller School of Medicine in Florida, and Alisa Femia, MD, New York University Grossman School of Medicine, New York City, in an accompanying editorial. Given that the median age in patients with cancer in the study was 58 years — 18 years older than the age cutoff for high-risk criteria — one way to refine the guidelines may be to increase the age for the high-risk category, they suggested.

“While these guidelines led to many ultimately unnecessary screening tests based on currently recommended designations of intermediate-risk and high-risk patients, these guidelines reflect a more conservative approach to screening than was previously performed,” Dr. Maderal and Dr. Femia wrote.

Jeff Gehlhausen, MD, PhD, an assistant professor of dermatology at Yale School of Medicine, New Haven, Connecticut, said he is not concerned about overscreening in patients, however, and is “very enthusiastic” about the findings.

“Patients are very anxious for good reason,” given the typical cancer prevalence of 25% in this population, he said in an interview. “I think therein lies the challenge — with that risk, what is ‘enough’ screening?” Yet this “incredibly impressive” study “provides real insights into the applicability of the IMACS screenings to our dermatomyositis management,” including relevance to his own patients. “Their findings are instructive for how to better evaluate these patients in a more mindful fashion,” he said, and they are particularly welcome, given how widely variable practice has historically been before the guidelines were issued.

“This question has been an outstanding one for decades, and nearly every doctor has a different answer,” Dr. Gehlhausen said. “The introduction of the guidelines alone are now much more actionable with this study, and that’s why it’s such an important one for our community.”

Benedict Wu, DO, PhD, director of Inpatient Dermatology and an assistant professor at Montefiore Einstein and a member of the Montefiore Einstein Comprehensive Cancer Center in New York City, similarly regarded the findings as reassuring, though he was surprised at the low prevalence of cancer in the patients.

“The most reassuring finding was that the detection of most malignancies was possible by using routine age- and sex-related screening combined with basic cancer screening,” Wu said in an interview. “Basic cancer screening can reduce costs while keeping patients safe.”

He also found it reassuring that all the paraneoplastic dermatomyositis was in intermediate- or high-risk patients, and while he does not see the IMACS guidelines as overestimating cancer risk, he does think “the risk stratification and recommended screening tests could be revised to be less ‘aggressive.’ ” 

The overall low rate of cancer in the group “calls into question the need for stringent and annual cancer screening,” he said. “In this large cohort of patients, the fact that malignancy was detected within 2 years of dermatomyositis diagnosis will help guide us with long-term screening recommendations.”

Despite the study’s small size and single-center design, the demographics of the patients nearly represents exactly what is found in the United States more broadly, Wu noted. He also drew attention to how many patients lacked the myositis antibody profile performed, and he agreed with the authors that more extensive and prospective studies need to be conducted. He also emphasized the need to keep in mind that “the primary goal of dermatomyositis management should focus on controlling/reducing the disease burden.”

The research was funded by the National Institutes of Health and the US Department of Veterans Affairs. The authors had no disclosures. Dr. Maderal reported personal fees from argenx. No disclosures were noted for Dr. Gehlhausen and Dr. Wu.

A version of this article appeared on Medscape.com.

Newly issued guidelines for cancer screening in patients with dermatomyositis had 100% sensitivity in a single institution’s cohort, though most of the cancers found would have been detected with standard cancer screenings recommended for the general population, according to a research letter published in JAMA Dermatology.

“These early results emphasize the continued need to refine risk assessment and cancer screening for patients with dermatomyositis while balancing resource use and outcomes,” concluded Caroline J. Stone and her colleagues at the Department of Dermatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia.

dermatology.cdlib.org/CC BY-SA 3.0/wikimedia

Patients with dermatomyositis have approximately a 4.7 times greater risk for cancer than those without it, according to a 2016 meta-analysis. Despite the well-established link between cancer and dermatomyositis, cancer in people with idiopathic inflammatory myopathies is commonly diagnosed at a later stage and is the leading cause of death in people with these conditions.
 

Guidelines First Presented in 2022 and Published in 2023

A wide variability in screening practices eventually led the International Myositis Assessment & Clinical Studies Group (IMACS) to present the first evidence-based and consensus-based guidelines for cancer screening of patients with idiopathic inflammatory myopathies, including those with dermatomyositis, at the 2022 annual meeting of the American College of Rheumatology and publish them in 2023 in Nature Reviews Rheumatology. The guidelines advise low-risk patients to undergo basic cancer screening with routine blood and urine studies, liver function tests, plain chest radiography, and age- and sex-appropriate cancer screening.

Intermediate- and high-risk patients are recommended to undergo enhanced screening that can include mammography, Pap tests, endoscopy/colonoscopy, pelvic and transvaginal ultrasonography, prostate-specific antigen or cancer antigen 125 blood tests, fecal occult blood tests, and CT of the neck, thorax, abdomen, and pelvis.

But because the guidelines are new, little evidence exists regarding their validation in real-world cohorts. Researchers, therefore, assessed the IMACS guidelines in 370 patients, aged 18-80 years, who visited the University of Pennsylvania rheumatology-dermatology specialty clinic between July 2008 and January 2024. All participants had dermatomyositis and at least 3 years of follow-up and were an average 48 years old. The vast majority were women (87%) and White participants (89%).

Most (68.6%) had myositis-specific autoantibody test results, one of the factors included in the guidelines for determining whether the patient should be classified as low, intermediate, or high risk. Other factors for risk stratification included myositis subtype, age at disease onset, and clinical features. About half (49.2%) had classic dermatomyositis, 42.4% had amyopathic dermatomyositis, 3.8% had juvenile dermatomyositis, 3.2% had hypomyopathic dermatomyositis, 0.8% had antisynthetase syndrome, and 0.5% had immune-mediated necrotizing myopathy.

Just over half the patients (54%) were classified as high risk, while 37.3% were classified as intermediate risk and 8.9% as low risk using the guidelines. Among the 18 patients (4.9%) with paraneoplastic dermatomyositis, 15 were classified as high risk and 3 as intermediate risk.

Of the patients diagnosed with cancer, 55% of cases were diagnosed about a year before their dermatomyositis diagnosis. In three patients, symptoms “suggestive of cancer at the time of dermatomyositis diagnosis, including lymphadenopathy and unexplained weight loss,” led to diagnostic testing that found an underlying cancer.

In the eight patients diagnosed with cancer after their dermatomyositis diagnosis, 75% of the cancers were identified during the first year of follow-up and 25% in the second year. Five were identified based on basic cancer screening and three on enhanced screening.

A total of 11 patients (3%) developed intravenous contrast allergies, and no other adverse events were reported to be associated with cancer screening, but the study was not designed to capture other types of adverse screening effects, such as cost, quality of life, or risk from radiation exposure.

The most common neoplasm identified was breast cancer, found in nine (50%) of the patients using mammography. Two patients had lung cancer identified with chest radiography and two had ovarian cancer identified with abdominal radiography and CT. The remaining five patients included one each with bladder cancer, papillary thyroid cancer, renal cell carcinoma, non-Hodgkin lymphoma, and adenocarcinoma with unknown primary.

The sensitivity of the guidelines in detecting cancer related to dermatomyositis was 100%, though the authors noted that the “IMACS risk-stratification scheme may overestimate cancer risk and encourage enhanced screening protocols of unclear benefit.” Most of the cancers found after dermatomyositis diagnosis were detected with routine age- and sex-related screening that already falls under basic cancer screening recommendations for the general population. Nonetheless, 90% of the participants fell into the intermediate- and high-risk groups, warranting a more comprehensive and costly enhanced screening protocol.
 

Will the Guidelines Lead to Overscreening? 

The 4.9% cancer prevalence is considerably lower than the typical 15%-25% prevalence among patients with dermatomyositis, but the findings, regardless, suggest the guidelines will lead to overscreening, wrote Andrea D. Maderal, MD, University of Miami Miller School of Medicine in Florida, and Alisa Femia, MD, New York University Grossman School of Medicine, New York City, in an accompanying editorial. Given that the median age in patients with cancer in the study was 58 years — 18 years older than the age cutoff for high-risk criteria — one way to refine the guidelines may be to increase the age for the high-risk category, they suggested.

“While these guidelines led to many ultimately unnecessary screening tests based on currently recommended designations of intermediate-risk and high-risk patients, these guidelines reflect a more conservative approach to screening than was previously performed,” Dr. Maderal and Dr. Femia wrote.

Jeff Gehlhausen, MD, PhD, an assistant professor of dermatology at Yale School of Medicine, New Haven, Connecticut, said he is not concerned about overscreening in patients, however, and is “very enthusiastic” about the findings.

“Patients are very anxious for good reason,” given the typical cancer prevalence of 25% in this population, he said in an interview. “I think therein lies the challenge — with that risk, what is ‘enough’ screening?” Yet this “incredibly impressive” study “provides real insights into the applicability of the IMACS screenings to our dermatomyositis management,” including relevance to his own patients. “Their findings are instructive for how to better evaluate these patients in a more mindful fashion,” he said, and they are particularly welcome, given how widely variable practice has historically been before the guidelines were issued.

“This question has been an outstanding one for decades, and nearly every doctor has a different answer,” Dr. Gehlhausen said. “The introduction of the guidelines alone are now much more actionable with this study, and that’s why it’s such an important one for our community.”

Benedict Wu, DO, PhD, director of Inpatient Dermatology and an assistant professor at Montefiore Einstein and a member of the Montefiore Einstein Comprehensive Cancer Center in New York City, similarly regarded the findings as reassuring, though he was surprised at the low prevalence of cancer in the patients.

“The most reassuring finding was that the detection of most malignancies was possible by using routine age- and sex-related screening combined with basic cancer screening,” Wu said in an interview. “Basic cancer screening can reduce costs while keeping patients safe.”

He also found it reassuring that all the paraneoplastic dermatomyositis was in intermediate- or high-risk patients, and while he does not see the IMACS guidelines as overestimating cancer risk, he does think “the risk stratification and recommended screening tests could be revised to be less ‘aggressive.’ ” 

The overall low rate of cancer in the group “calls into question the need for stringent and annual cancer screening,” he said. “In this large cohort of patients, the fact that malignancy was detected within 2 years of dermatomyositis diagnosis will help guide us with long-term screening recommendations.”

Despite the study’s small size and single-center design, the demographics of the patients nearly represents exactly what is found in the United States more broadly, Wu noted. He also drew attention to how many patients lacked the myositis antibody profile performed, and he agreed with the authors that more extensive and prospective studies need to be conducted. He also emphasized the need to keep in mind that “the primary goal of dermatomyositis management should focus on controlling/reducing the disease burden.”

The research was funded by the National Institutes of Health and the US Department of Veterans Affairs. The authors had no disclosures. Dr. Maderal reported personal fees from argenx. No disclosures were noted for Dr. Gehlhausen and Dr. Wu.

A version of this article appeared on Medscape.com.

EDITOR’S NOTE

This year, we again focus on rare neurological diseases that have new therapies that have been recently approved as well as conditions for which the treatment pipeline is robust. Let’s hope the work of many dedicated researchers adds to the list of rare neurological diseases for which treatment is available.

This year also marks a change of leadership at NORD, our publishing partner in this annual supplement. We here at Neurology Reviews salute the leadership and accomplishments of former NORD CEO Peter Saltonstall and also welcome incoming CEO Pamela Gavin, who has spent many years in NORD leadership roles and was essential in the planning, launch, and early years of this annual supplement. I can think of no one better than Pamela Gavin to continue NORD’s mission into the future.

And finally, a recap of accolades for this annual supplement. For the second year in a row, the Rare Neurological Disease Special Report has won an Azbee award in the category of annual supplement from the American Society of Business Publication Editors. The 2023 issue won a National Gold Award and a Regional Gold Award.

—Glenn Williams, VP, Group Editor, Neurology Reviews and MDedge Neurology

A NOTE FROM NORD

Hello, and Welcome! The National Organization for Rare Disorders (NORD) is pleased to partner with Neurology Reviews to bring you the 2024 edition of the Rare Neurological Disease Report. Through this collaboration, we share cutting-edge research and insights from leading medical experts, including specialists from the NORD Rare Disease Centers of Excellence network, about the latest advances in the treatment of rare neurological conditions.

As healthcare providers, you play a key role in catalyzing advancements and bringing new hope and possibilities to the rare disease community. Your efforts can contribute to shortening the diagnostic odyssey and improving day-to-day care for people living with rare disorders in crucial ways:

Identifying patients: Healthcare providers can recognize the possible signs of a rare disease and initiate further investigation or referral to specialists. Early detection is key as it can lead to a quicker, more accurate diagnosis, better management, and improved outcomes.

Educating other physicians: Many rare diseases are not well-known or understood by the general medical community. Healthcare providers can help bridge this knowledge gap by educating other physicians about rare conditions. They can raise awareness through clinical teaching, seminars, medical literature, or continuing medical education (CME) sessions focused on rare diseases. Raising awareness and providing up-to-date information about rare diseases bolsters diagnostic and treatment capabilities within the medical field.

Providing information to patients: Once a rare disease is identified, healthcare providers can offer valuable support to patients and their families. They can provide potential treatments and management strategies. They can also connect patients with support groups, support programs, educational resources, and specialists with expertise in specific rare conditions. Clear communication and guidance on support resources can positively impact patients’ well-being, empower them to make informed decisions, and help them navigate a complex rare condition.

This issue of the Rare Disease Neurological Special Report features articles by rare disease medical experts on specific diseases with updates on clinical management. Topics include the diagnosis and management of Duchenne muscular dystrophy, the promise of disease-modifying therapies for Huntington’s disease, patient choices and cultural changes around myasthenia gravis, advances in neuromyelitis optica, and untangling chronic inflammatory demyelinating polyneuropathy. In addition, two online-only articles offer timely insights from key opinion leaders on the pros and cons of genetic testing and what clinicians need to know about newborn screening.

You will also find information about the NORD Rare Diseases and Orphan Products Breakthrough Summit. This annual event convenes thought leaders from patient advocacy organizations, industry, academia, medical and research institutions, and government to discuss critical topics facing the rare disease community. 

NORD is deeply appreciative of healthcare professionals like you, who despite long hours and demanding workloads, remain committed to staying up to date on the latest medical advances for the benefit of their patients. Your dedication and hard work make a significant difference to the patients and families we serve, and your commitment does not go unnoticed. Thank you for all that you do.

—Pamela Gavin, NORD Chief Executive Officer

EDITOR’S NOTE

This year, we again focus on rare neurological diseases that have new therapies that have been recently approved as well as conditions for which the treatment pipeline is robust. Let’s hope the work of many dedicated researchers adds to the list of rare neurological diseases for which treatment is available.

This year also marks a change of leadership at NORD, our publishing partner in this annual supplement. We here at Neurology Reviews salute the leadership and accomplishments of former NORD CEO Peter Saltonstall and also welcome incoming CEO Pamela Gavin, who has spent many years in NORD leadership roles and was essential in the planning, launch, and early years of this annual supplement. I can think of no one better than Pamela Gavin to continue NORD’s mission into the future.

And finally, a recap of accolades for this annual supplement. For the second year in a row, the Rare Neurological Disease Special Report has won an Azbee award in the category of annual supplement from the American Society of Business Publication Editors. The 2023 issue won a National Gold Award and a Regional Gold Award.

—Glenn Williams, VP, Group Editor, Neurology Reviews and MDedge Neurology

A NOTE FROM NORD

Hello, and Welcome! The National Organization for Rare Disorders (NORD) is pleased to partner with Neurology Reviews to bring you the 2024 edition of the Rare Neurological Disease Report. Through this collaboration, we share cutting-edge research and insights from leading medical experts, including specialists from the NORD Rare Disease Centers of Excellence network, about the latest advances in the treatment of rare neurological conditions.

As healthcare providers, you play a key role in catalyzing advancements and bringing new hope and possibilities to the rare disease community. Your efforts can contribute to shortening the diagnostic odyssey and improving day-to-day care for people living with rare disorders in crucial ways:

Identifying patients: Healthcare providers can recognize the possible signs of a rare disease and initiate further investigation or referral to specialists. Early detection is key as it can lead to a quicker, more accurate diagnosis, better management, and improved outcomes.

Educating other physicians: Many rare diseases are not well-known or understood by the general medical community. Healthcare providers can help bridge this knowledge gap by educating other physicians about rare conditions. They can raise awareness through clinical teaching, seminars, medical literature, or continuing medical education (CME) sessions focused on rare diseases. Raising awareness and providing up-to-date information about rare diseases bolsters diagnostic and treatment capabilities within the medical field.

Providing information to patients: Once a rare disease is identified, healthcare providers can offer valuable support to patients and their families. They can provide potential treatments and management strategies. They can also connect patients with support groups, support programs, educational resources, and specialists with expertise in specific rare conditions. Clear communication and guidance on support resources can positively impact patients’ well-being, empower them to make informed decisions, and help them navigate a complex rare condition.

This issue of the Rare Disease Neurological Special Report features articles by rare disease medical experts on specific diseases with updates on clinical management. Topics include the diagnosis and management of Duchenne muscular dystrophy, the promise of disease-modifying therapies for Huntington’s disease, patient choices and cultural changes around myasthenia gravis, advances in neuromyelitis optica, and untangling chronic inflammatory demyelinating polyneuropathy. In addition, two online-only articles offer timely insights from key opinion leaders on the pros and cons of genetic testing and what clinicians need to know about newborn screening.

You will also find information about the NORD Rare Diseases and Orphan Products Breakthrough Summit. This annual event convenes thought leaders from patient advocacy organizations, industry, academia, medical and research institutions, and government to discuss critical topics facing the rare disease community. 

NORD is deeply appreciative of healthcare professionals like you, who despite long hours and demanding workloads, remain committed to staying up to date on the latest medical advances for the benefit of their patients. Your dedication and hard work make a significant difference to the patients and families we serve, and your commitment does not go unnoticed. Thank you for all that you do.

—Pamela Gavin, NORD Chief Executive Officer

EDITOR’S NOTE

This year, we again focus on rare neurological diseases that have new therapies that have been recently approved as well as conditions for which the treatment pipeline is robust. Let’s hope the work of many dedicated researchers adds to the list of rare neurological diseases for which treatment is available.

This year also marks a change of leadership at NORD, our publishing partner in this annual supplement. We here at Neurology Reviews salute the leadership and accomplishments of former NORD CEO Peter Saltonstall and also welcome incoming CEO Pamela Gavin, who has spent many years in NORD leadership roles and was essential in the planning, launch, and early years of this annual supplement. I can think of no one better than Pamela Gavin to continue NORD’s mission into the future.

And finally, a recap of accolades for this annual supplement. For the second year in a row, the Rare Neurological Disease Special Report has won an Azbee award in the category of annual supplement from the American Society of Business Publication Editors. The 2023 issue won a National Gold Award and a Regional Gold Award.

—Glenn Williams, VP, Group Editor, Neurology Reviews and MDedge Neurology

A NOTE FROM NORD

Hello, and Welcome! The National Organization for Rare Disorders (NORD) is pleased to partner with Neurology Reviews to bring you the 2024 edition of the Rare Neurological Disease Report. Through this collaboration, we share cutting-edge research and insights from leading medical experts, including specialists from the NORD Rare Disease Centers of Excellence network, about the latest advances in the treatment of rare neurological conditions.

As healthcare providers, you play a key role in catalyzing advancements and bringing new hope and possibilities to the rare disease community. Your efforts can contribute to shortening the diagnostic odyssey and improving day-to-day care for people living with rare disorders in crucial ways:

Identifying patients: Healthcare providers can recognize the possible signs of a rare disease and initiate further investigation or referral to specialists. Early detection is key as it can lead to a quicker, more accurate diagnosis, better management, and improved outcomes.

Educating other physicians: Many rare diseases are not well-known or understood by the general medical community. Healthcare providers can help bridge this knowledge gap by educating other physicians about rare conditions. They can raise awareness through clinical teaching, seminars, medical literature, or continuing medical education (CME) sessions focused on rare diseases. Raising awareness and providing up-to-date information about rare diseases bolsters diagnostic and treatment capabilities within the medical field.

Providing information to patients: Once a rare disease is identified, healthcare providers can offer valuable support to patients and their families. They can provide potential treatments and management strategies. They can also connect patients with support groups, support programs, educational resources, and specialists with expertise in specific rare conditions. Clear communication and guidance on support resources can positively impact patients’ well-being, empower them to make informed decisions, and help them navigate a complex rare condition.

This issue of the Rare Disease Neurological Special Report features articles by rare disease medical experts on specific diseases with updates on clinical management. Topics include the diagnosis and management of Duchenne muscular dystrophy, the promise of disease-modifying therapies for Huntington’s disease, patient choices and cultural changes around myasthenia gravis, advances in neuromyelitis optica, and untangling chronic inflammatory demyelinating polyneuropathy. In addition, two online-only articles offer timely insights from key opinion leaders on the pros and cons of genetic testing and what clinicians need to know about newborn screening.

You will also find information about the NORD Rare Diseases and Orphan Products Breakthrough Summit. This annual event convenes thought leaders from patient advocacy organizations, industry, academia, medical and research institutions, and government to discuss critical topics facing the rare disease community. 

NORD is deeply appreciative of healthcare professionals like you, who despite long hours and demanding workloads, remain committed to staying up to date on the latest medical advances for the benefit of their patients. Your dedication and hard work make a significant difference to the patients and families we serve, and your commitment does not go unnoticed. Thank you for all that you do.

—Pamela Gavin, NORD Chief Executive Officer

The overwhelming majority of rare diseases have a genetic origin, with estimates varying from 71.9% to 80% of rare diseases. Although a rare disease is defined as a condition that affects fewer than 200,000 people domestically, collectively, rare diseases impact approximately 30 million US residents, with at least one of the more than 7,000 rare genetic disorders. In fact, the population of patients with at least one rare disease mirrors the prevalence of people who have type 2 diabetes, or one in every 10 people. Despite their prevalence, most rare conditions are treated only when symptomatic, as many cases remain either misdiagnosed or undiagnosed. As with most health conditions, it is imperative to have a prompt and accurate diagnosis to improve outcomes and avoid inappropriate or unnecessary treatments that may pose severe side effects to the patient.

As the push toward prompt testing and treatment of rare diseases continues building momentum, it has cast a growing spotlight on genetic testing and its potential. To that end, this report weighs the less obvious pros and cons of genetic testing in rare diseases of which neurologists should be aware.
 

The Path to Accurate Diagnosis Remains Long Despite Increased Genetic Testing

When it comes to identifying the greatest challenge in rare genetic disease testing for the neurology community, experts have different opinions. For Kiley Boone Quintana, MD, assistant professor of pediatrics at the University of New Mexico in Albuquerque, the greatest challenge for neurologists navigating this space lies in becoming comfortable with the unknown.

“Many neurologists think genetic testing will certainly find an answer or that the answers will be black and white — which is not true,” said Dr. Quintana. “Instead of clear answers, we often find variants of unknown significance and genetic changes like a deletion or duplication that can have reduced penetrance, so clinicians have to become comfortable with not always having an answer or not knowing exactly how the answer will impact the person.”

Whole Exome and Whole Genome Testing Continues Growing in Prevalence, But Neither Offers a Panacea

Historically, genetic testing was expensive, with only a few genes interrogated at a time. However, the past decade has seen prices simmer down with the introduction of next-generation sequencing — a technology that improves both the accuracy and utility of genetic testing.

One form of genetic testing, called whole exome sequencing, has proven especially helpful in recent years because it looks at all 20,000 genes and spelling changes that can cause mutations and genetic diseases. However, whole exome testing comes with its own limitations. It tests at the DNA loci that produce the actual protein blueprints but does not look at the DNA between those spaces. In addition, the medical community lacks a comprehensive understanding of all 20,000 genes, as scientists have yet to understand all their functions.

Unfortunately, the drawbacks do not stop there.

“Whole exome sequencing is not good at detecting conditions such as Huntington’s disease or Fragile X syndrome,” Dr. Quintana said. “It also fails to pick up spelling changes in DNA of noncoding regions, which we are learning do have functions in epigenetics.”

Quality also can limit reliability of both exome and genome testing. According to Dr. Regier, trustworthiness of results depends on several factors, including the lab conducting the test and the analysis performed. To help ensure quality, Dr. Regier and her colleagues use only CLIA-certified labs and labs that follow the American College of Medical Genetics (ACMG) guidelines. Furthermore, they allow only qualified experts to analyze the results, experts who hold board certifications with either the American College of Medical Genetics and Genomics or the American Board of Pathology.
 

Familial and Societal Stigma Surrounding Rare Diseases Engenders Emotional, Psychological, and Financial Distress

Ultimately, traversing the trajectory of delayed diagnosis and its ambiguity also leaves questions regarding how it will impact the person. All too often, these mysteries transcend the patient with the condition, affecting relatives and other loved ones, as the familial and societal stigma surrounding rare diseases engenders emotional and psychological distress.

In cases with prolonged or delayed diagnostics, Dr. Quintana said that neurologists should advise patients to prepare themselves for the potential of arduous workups — some of which may also come at a high price. Not only does a circuitous path to diagnosis impede treatment initiation, but it often results in major trauma for patients and their caregivers, who encounter significant emotional, psychological, and financial distress in the fallout. Emotional distress of misdiagnosis or lack of a diagnosis remains a significant pain point for patients and their family members alike.

Emotional distress presents the greatest drawback for the rare disease community, according to Dr. Regier. She described the cons of navigating a rare genetic disease diagnosis as “very personal” for families.

“Sometimes, there can be guilt or shame associated with a genetic illness,” Dr. Regier noted. “Understanding the ‘why’ or knowing better how to use nonspecific treatments can be incredibly important to reduce guilt and shame, but it also allows the family to feel like there is a reason and encourages inclusion in the social setting.”

Diagnosis typically results in inclusion in a patient and family group, which increases understanding while easing some of the psychological and emotional stress associated with not knowing the cause.
 

Establishing Social Support Networks Typically Falls on the Patient and Loved Ones

Another con in rare genetic diseases is the lack of adoption across the community.

Because of the long haul, neurologists and other clinicians should recognize the need for patients to have support. Both Dr. Regier and Dr. Quintana agreed that communal support is a critical component of managing the rare genetic disease population. However, finding one’s tribe is easier said than done. Due to the diagnostic hurdles and low number of people with confirmed diagnoses, patient communities and patient advocacy groups for people with individual rare diseases can be underdeveloped. However, the importance of family-based support groups should not be understated. The low community head counts and high level of time investment for care also contributes to poor recruitment turnouts for clinical trials and, subsequently, the sparse number of therapies for such conditions in the pipeline. However, it is also worth noting that, in the case of rare diseases, insufficient disease state knowledge, antiquated policies, lack of funding, and poor research and development diagnostic infrastructure also amplify such cons.

Patients can form communities of support by finding other families and knowing what to expect in terms of complications. While clinicians may not always have the resources to help the patient establish support systems, they can increase the patients’ awareness and encourage them to search for groups that align with their needs. Dr. Quintana reported that many of her patients find support groups of people with the same rare conditions through social media outlets such as Facebook.
 

Lack of Widespread Genetic Testing Adoption Remains a Barrier in Rare Diseases

As Dr. Quintana told Neurology Reviews, geneticists are more likely to order exome testing, despite the fact that genome-wide testing is slightly more likely to find a diagnosis. However, she anticipates that genome-wide testing will gain wider adoption in the future.

In terms of cost and feasibility, genetic testing can identify roughly 50% of the underlying etiology of a rare disease, including phenotyping to make a clinical diagnosis and using genetic testing, according to Dr. Regier.

Regarding the broad use of whole genome sequencing, Dr. Regier foresees that the more we learn about all the diagnostic and prognostic information rare disease testing can give us, “the more this number will grow.”

As an example of the true impact, she shared how new research indicates that changes to one’s DNA can lead to intellectual disability.

Dr. Quintana agreed that genetic testing will increase, noting an increase in genetic testing ordered from neonatal intensive care units. However, that uptick comes with the caveat of an ever-evolving landscape as genetic companies continue undergoing mergers, acquisitions, and other structural changes that can complicate service availability, provision, and acceptance.

Even if the clinician orders a comprehensive workup, he or she may still encounter resistance at the hands of insurance companies, which can prolong an accurate and prompt diagnosis while hindering families’ access to a thorough investigation.

“Genetic testing is advantageous for insurance companies as well and can prevent unnecessary lab tests to find an answer,” said Dr. Quintana.
 

Accessibility and Lack of Geneticists Often a Rate-Limiting Step

The paucity of geneticists also creates another hurdle. “Where I practice in New Mexico and in many other places in this country, there’s a shortage of geneticists,” Dr. Quintana said. “For 3 years, the state had only one geneticist, and that’s a lot of ground to cover.”

Dr. Quintana went on to stress the importance of neurologists and other clinicians conducting outreach in rural areas despite the logistical barriers; oftentimes, families cannot travel to big cities. Despite these geographical challenges, prenatal genetic testing is becoming more accessible for both rural and urban areas. For that reason, some babies are born with a diagnosis, allowing the parents and healthcare providers to take immediate action.

Moreover, risks and uncertainty exist around genetic testing results and access to long-term life insurance and disability insurance coverage. “Obtaining proper consent prior to genetic testing is very important,” said Dr. Quintana.

In many cases, genetic counseling may be beneficial because it offers patients some additional information and resources that help them understand not only the results of their genetic tests but also the consequences of their conditions.
 

Ultimately, Genetic Testing in Rare Diseases Requires All Stakeholders to Have Patience and Tenacity

Dr. Regier summarized some of the nuances of genetic testing in the rare disease community. “Families understand that you might not be able to make the diagnosis,” Dr. Regier said. “It is more important to them that you stay on the journey with them, even if there is not a diagnosis.”

Another critical element of the diagnostic voyage hinges on clinicians recognizing and honoring that every family ­— and patient — is different.

“Some families want to do testing while others want to take one thing at a time and start with symptom management,” Dr. Regier said. “Both of these approaches are good, and every family has the right to decide when and if genetic testing should be part of their diagnostic odyssey.”

Suggested Reading

Baynam G et al. Stigma Associated With Genetic Testing for Rare Diseases — Causes and Recommendations. Front Genet. 2024 Apr 4:15:1335768. doi: 10.3389/fgene.2024.1335768.

Marwaha S et al. A Guide for the Diagnosis of Rare and Undiagnosed Disease: Beyond the Exome. Genome Med. 2022 Feb 28;14(1):23. doi: 10.1186/s13073-022-01026-w.

The overwhelming majority of rare diseases have a genetic origin, with estimates varying from 71.9% to 80% of rare diseases. Although a rare disease is defined as a condition that affects fewer than 200,000 people domestically, collectively, rare diseases impact approximately 30 million US residents, with at least one of the more than 7,000 rare genetic disorders. In fact, the population of patients with at least one rare disease mirrors the prevalence of people who have type 2 diabetes, or one in every 10 people. Despite their prevalence, most rare conditions are treated only when symptomatic, as many cases remain either misdiagnosed or undiagnosed. As with most health conditions, it is imperative to have a prompt and accurate diagnosis to improve outcomes and avoid inappropriate or unnecessary treatments that may pose severe side effects to the patient.

As the push toward prompt testing and treatment of rare diseases continues building momentum, it has cast a growing spotlight on genetic testing and its potential. To that end, this report weighs the less obvious pros and cons of genetic testing in rare diseases of which neurologists should be aware.
 

The Path to Accurate Diagnosis Remains Long Despite Increased Genetic Testing

When it comes to identifying the greatest challenge in rare genetic disease testing for the neurology community, experts have different opinions. For Kiley Boone Quintana, MD, assistant professor of pediatrics at the University of New Mexico in Albuquerque, the greatest challenge for neurologists navigating this space lies in becoming comfortable with the unknown.

“Many neurologists think genetic testing will certainly find an answer or that the answers will be black and white — which is not true,” said Dr. Quintana. “Instead of clear answers, we often find variants of unknown significance and genetic changes like a deletion or duplication that can have reduced penetrance, so clinicians have to become comfortable with not always having an answer or not knowing exactly how the answer will impact the person.”

Whole Exome and Whole Genome Testing Continues Growing in Prevalence, But Neither Offers a Panacea

Historically, genetic testing was expensive, with only a few genes interrogated at a time. However, the past decade has seen prices simmer down with the introduction of next-generation sequencing — a technology that improves both the accuracy and utility of genetic testing.

One form of genetic testing, called whole exome sequencing, has proven especially helpful in recent years because it looks at all 20,000 genes and spelling changes that can cause mutations and genetic diseases. However, whole exome testing comes with its own limitations. It tests at the DNA loci that produce the actual protein blueprints but does not look at the DNA between those spaces. In addition, the medical community lacks a comprehensive understanding of all 20,000 genes, as scientists have yet to understand all their functions.

Unfortunately, the drawbacks do not stop there.

“Whole exome sequencing is not good at detecting conditions such as Huntington’s disease or Fragile X syndrome,” Dr. Quintana said. “It also fails to pick up spelling changes in DNA of noncoding regions, which we are learning do have functions in epigenetics.”

Quality also can limit reliability of both exome and genome testing. According to Dr. Regier, trustworthiness of results depends on several factors, including the lab conducting the test and the analysis performed. To help ensure quality, Dr. Regier and her colleagues use only CLIA-certified labs and labs that follow the American College of Medical Genetics (ACMG) guidelines. Furthermore, they allow only qualified experts to analyze the results, experts who hold board certifications with either the American College of Medical Genetics and Genomics or the American Board of Pathology.
 

Familial and Societal Stigma Surrounding Rare Diseases Engenders Emotional, Psychological, and Financial Distress

Ultimately, traversing the trajectory of delayed diagnosis and its ambiguity also leaves questions regarding how it will impact the person. All too often, these mysteries transcend the patient with the condition, affecting relatives and other loved ones, as the familial and societal stigma surrounding rare diseases engenders emotional and psychological distress.

In cases with prolonged or delayed diagnostics, Dr. Quintana said that neurologists should advise patients to prepare themselves for the potential of arduous workups — some of which may also come at a high price. Not only does a circuitous path to diagnosis impede treatment initiation, but it often results in major trauma for patients and their caregivers, who encounter significant emotional, psychological, and financial distress in the fallout. Emotional distress of misdiagnosis or lack of a diagnosis remains a significant pain point for patients and their family members alike.

Emotional distress presents the greatest drawback for the rare disease community, according to Dr. Regier. She described the cons of navigating a rare genetic disease diagnosis as “very personal” for families.

“Sometimes, there can be guilt or shame associated with a genetic illness,” Dr. Regier noted. “Understanding the ‘why’ or knowing better how to use nonspecific treatments can be incredibly important to reduce guilt and shame, but it also allows the family to feel like there is a reason and encourages inclusion in the social setting.”

Diagnosis typically results in inclusion in a patient and family group, which increases understanding while easing some of the psychological and emotional stress associated with not knowing the cause.
 

Establishing Social Support Networks Typically Falls on the Patient and Loved Ones

Another con in rare genetic diseases is the lack of adoption across the community.

Because of the long haul, neurologists and other clinicians should recognize the need for patients to have support. Both Dr. Regier and Dr. Quintana agreed that communal support is a critical component of managing the rare genetic disease population. However, finding one’s tribe is easier said than done. Due to the diagnostic hurdles and low number of people with confirmed diagnoses, patient communities and patient advocacy groups for people with individual rare diseases can be underdeveloped. However, the importance of family-based support groups should not be understated. The low community head counts and high level of time investment for care also contributes to poor recruitment turnouts for clinical trials and, subsequently, the sparse number of therapies for such conditions in the pipeline. However, it is also worth noting that, in the case of rare diseases, insufficient disease state knowledge, antiquated policies, lack of funding, and poor research and development diagnostic infrastructure also amplify such cons.

Patients can form communities of support by finding other families and knowing what to expect in terms of complications. While clinicians may not always have the resources to help the patient establish support systems, they can increase the patients’ awareness and encourage them to search for groups that align with their needs. Dr. Quintana reported that many of her patients find support groups of people with the same rare conditions through social media outlets such as Facebook.
 

Lack of Widespread Genetic Testing Adoption Remains a Barrier in Rare Diseases

As Dr. Quintana told Neurology Reviews, geneticists are more likely to order exome testing, despite the fact that genome-wide testing is slightly more likely to find a diagnosis. However, she anticipates that genome-wide testing will gain wider adoption in the future.

In terms of cost and feasibility, genetic testing can identify roughly 50% of the underlying etiology of a rare disease, including phenotyping to make a clinical diagnosis and using genetic testing, according to Dr. Regier.

Regarding the broad use of whole genome sequencing, Dr. Regier foresees that the more we learn about all the diagnostic and prognostic information rare disease testing can give us, “the more this number will grow.”

As an example of the true impact, she shared how new research indicates that changes to one’s DNA can lead to intellectual disability.

Dr. Quintana agreed that genetic testing will increase, noting an increase in genetic testing ordered from neonatal intensive care units. However, that uptick comes with the caveat of an ever-evolving landscape as genetic companies continue undergoing mergers, acquisitions, and other structural changes that can complicate service availability, provision, and acceptance.

Even if the clinician orders a comprehensive workup, he or she may still encounter resistance at the hands of insurance companies, which can prolong an accurate and prompt diagnosis while hindering families’ access to a thorough investigation.

“Genetic testing is advantageous for insurance companies as well and can prevent unnecessary lab tests to find an answer,” said Dr. Quintana.
 

Accessibility and Lack of Geneticists Often a Rate-Limiting Step

The paucity of geneticists also creates another hurdle. “Where I practice in New Mexico and in many other places in this country, there’s a shortage of geneticists,” Dr. Quintana said. “For 3 years, the state had only one geneticist, and that’s a lot of ground to cover.”

Dr. Quintana went on to stress the importance of neurologists and other clinicians conducting outreach in rural areas despite the logistical barriers; oftentimes, families cannot travel to big cities. Despite these geographical challenges, prenatal genetic testing is becoming more accessible for both rural and urban areas. For that reason, some babies are born with a diagnosis, allowing the parents and healthcare providers to take immediate action.

Moreover, risks and uncertainty exist around genetic testing results and access to long-term life insurance and disability insurance coverage. “Obtaining proper consent prior to genetic testing is very important,” said Dr. Quintana.

In many cases, genetic counseling may be beneficial because it offers patients some additional information and resources that help them understand not only the results of their genetic tests but also the consequences of their conditions.
 

Ultimately, Genetic Testing in Rare Diseases Requires All Stakeholders to Have Patience and Tenacity

Dr. Regier summarized some of the nuances of genetic testing in the rare disease community. “Families understand that you might not be able to make the diagnosis,” Dr. Regier said. “It is more important to them that you stay on the journey with them, even if there is not a diagnosis.”

Another critical element of the diagnostic voyage hinges on clinicians recognizing and honoring that every family ­— and patient — is different.

“Some families want to do testing while others want to take one thing at a time and start with symptom management,” Dr. Regier said. “Both of these approaches are good, and every family has the right to decide when and if genetic testing should be part of their diagnostic odyssey.”

Suggested Reading

Baynam G et al. Stigma Associated With Genetic Testing for Rare Diseases — Causes and Recommendations. Front Genet. 2024 Apr 4:15:1335768. doi: 10.3389/fgene.2024.1335768.

Marwaha S et al. A Guide for the Diagnosis of Rare and Undiagnosed Disease: Beyond the Exome. Genome Med. 2022 Feb 28;14(1):23. doi: 10.1186/s13073-022-01026-w.

The overwhelming majority of rare diseases have a genetic origin, with estimates varying from 71.9% to 80% of rare diseases. Although a rare disease is defined as a condition that affects fewer than 200,000 people domestically, collectively, rare diseases impact approximately 30 million US residents, with at least one of the more than 7,000 rare genetic disorders. In fact, the population of patients with at least one rare disease mirrors the prevalence of people who have type 2 diabetes, or one in every 10 people. Despite their prevalence, most rare conditions are treated only when symptomatic, as many cases remain either misdiagnosed or undiagnosed. As with most health conditions, it is imperative to have a prompt and accurate diagnosis to improve outcomes and avoid inappropriate or unnecessary treatments that may pose severe side effects to the patient.

As the push toward prompt testing and treatment of rare diseases continues building momentum, it has cast a growing spotlight on genetic testing and its potential. To that end, this report weighs the less obvious pros and cons of genetic testing in rare diseases of which neurologists should be aware.
 

The Path to Accurate Diagnosis Remains Long Despite Increased Genetic Testing

When it comes to identifying the greatest challenge in rare genetic disease testing for the neurology community, experts have different opinions. For Kiley Boone Quintana, MD, assistant professor of pediatrics at the University of New Mexico in Albuquerque, the greatest challenge for neurologists navigating this space lies in becoming comfortable with the unknown.

“Many neurologists think genetic testing will certainly find an answer or that the answers will be black and white — which is not true,” said Dr. Quintana. “Instead of clear answers, we often find variants of unknown significance and genetic changes like a deletion or duplication that can have reduced penetrance, so clinicians have to become comfortable with not always having an answer or not knowing exactly how the answer will impact the person.”

Whole Exome and Whole Genome Testing Continues Growing in Prevalence, But Neither Offers a Panacea

Historically, genetic testing was expensive, with only a few genes interrogated at a time. However, the past decade has seen prices simmer down with the introduction of next-generation sequencing — a technology that improves both the accuracy and utility of genetic testing.

One form of genetic testing, called whole exome sequencing, has proven especially helpful in recent years because it looks at all 20,000 genes and spelling changes that can cause mutations and genetic diseases. However, whole exome testing comes with its own limitations. It tests at the DNA loci that produce the actual protein blueprints but does not look at the DNA between those spaces. In addition, the medical community lacks a comprehensive understanding of all 20,000 genes, as scientists have yet to understand all their functions.

Unfortunately, the drawbacks do not stop there.

“Whole exome sequencing is not good at detecting conditions such as Huntington’s disease or Fragile X syndrome,” Dr. Quintana said. “It also fails to pick up spelling changes in DNA of noncoding regions, which we are learning do have functions in epigenetics.”

Quality also can limit reliability of both exome and genome testing. According to Dr. Regier, trustworthiness of results depends on several factors, including the lab conducting the test and the analysis performed. To help ensure quality, Dr. Regier and her colleagues use only CLIA-certified labs and labs that follow the American College of Medical Genetics (ACMG) guidelines. Furthermore, they allow only qualified experts to analyze the results, experts who hold board certifications with either the American College of Medical Genetics and Genomics or the American Board of Pathology.
 

Familial and Societal Stigma Surrounding Rare Diseases Engenders Emotional, Psychological, and Financial Distress

Ultimately, traversing the trajectory of delayed diagnosis and its ambiguity also leaves questions regarding how it will impact the person. All too often, these mysteries transcend the patient with the condition, affecting relatives and other loved ones, as the familial and societal stigma surrounding rare diseases engenders emotional and psychological distress.

In cases with prolonged or delayed diagnostics, Dr. Quintana said that neurologists should advise patients to prepare themselves for the potential of arduous workups — some of which may also come at a high price. Not only does a circuitous path to diagnosis impede treatment initiation, but it often results in major trauma for patients and their caregivers, who encounter significant emotional, psychological, and financial distress in the fallout. Emotional distress of misdiagnosis or lack of a diagnosis remains a significant pain point for patients and their family members alike.

Emotional distress presents the greatest drawback for the rare disease community, according to Dr. Regier. She described the cons of navigating a rare genetic disease diagnosis as “very personal” for families.

“Sometimes, there can be guilt or shame associated with a genetic illness,” Dr. Regier noted. “Understanding the ‘why’ or knowing better how to use nonspecific treatments can be incredibly important to reduce guilt and shame, but it also allows the family to feel like there is a reason and encourages inclusion in the social setting.”

Diagnosis typically results in inclusion in a patient and family group, which increases understanding while easing some of the psychological and emotional stress associated with not knowing the cause.
 

Establishing Social Support Networks Typically Falls on the Patient and Loved Ones

Another con in rare genetic diseases is the lack of adoption across the community.

Because of the long haul, neurologists and other clinicians should recognize the need for patients to have support. Both Dr. Regier and Dr. Quintana agreed that communal support is a critical component of managing the rare genetic disease population. However, finding one’s tribe is easier said than done. Due to the diagnostic hurdles and low number of people with confirmed diagnoses, patient communities and patient advocacy groups for people with individual rare diseases can be underdeveloped. However, the importance of family-based support groups should not be understated. The low community head counts and high level of time investment for care also contributes to poor recruitment turnouts for clinical trials and, subsequently, the sparse number of therapies for such conditions in the pipeline. However, it is also worth noting that, in the case of rare diseases, insufficient disease state knowledge, antiquated policies, lack of funding, and poor research and development diagnostic infrastructure also amplify such cons.

Patients can form communities of support by finding other families and knowing what to expect in terms of complications. While clinicians may not always have the resources to help the patient establish support systems, they can increase the patients’ awareness and encourage them to search for groups that align with their needs. Dr. Quintana reported that many of her patients find support groups of people with the same rare conditions through social media outlets such as Facebook.
 

Lack of Widespread Genetic Testing Adoption Remains a Barrier in Rare Diseases

As Dr. Quintana told Neurology Reviews, geneticists are more likely to order exome testing, despite the fact that genome-wide testing is slightly more likely to find a diagnosis. However, she anticipates that genome-wide testing will gain wider adoption in the future.

In terms of cost and feasibility, genetic testing can identify roughly 50% of the underlying etiology of a rare disease, including phenotyping to make a clinical diagnosis and using genetic testing, according to Dr. Regier.

Regarding the broad use of whole genome sequencing, Dr. Regier foresees that the more we learn about all the diagnostic and prognostic information rare disease testing can give us, “the more this number will grow.”

As an example of the true impact, she shared how new research indicates that changes to one’s DNA can lead to intellectual disability.

Dr. Quintana agreed that genetic testing will increase, noting an increase in genetic testing ordered from neonatal intensive care units. However, that uptick comes with the caveat of an ever-evolving landscape as genetic companies continue undergoing mergers, acquisitions, and other structural changes that can complicate service availability, provision, and acceptance.

Even if the clinician orders a comprehensive workup, he or she may still encounter resistance at the hands of insurance companies, which can prolong an accurate and prompt diagnosis while hindering families’ access to a thorough investigation.

“Genetic testing is advantageous for insurance companies as well and can prevent unnecessary lab tests to find an answer,” said Dr. Quintana.
 

Accessibility and Lack of Geneticists Often a Rate-Limiting Step

The paucity of geneticists also creates another hurdle. “Where I practice in New Mexico and in many other places in this country, there’s a shortage of geneticists,” Dr. Quintana said. “For 3 years, the state had only one geneticist, and that’s a lot of ground to cover.”

Dr. Quintana went on to stress the importance of neurologists and other clinicians conducting outreach in rural areas despite the logistical barriers; oftentimes, families cannot travel to big cities. Despite these geographical challenges, prenatal genetic testing is becoming more accessible for both rural and urban areas. For that reason, some babies are born with a diagnosis, allowing the parents and healthcare providers to take immediate action.

Moreover, risks and uncertainty exist around genetic testing results and access to long-term life insurance and disability insurance coverage. “Obtaining proper consent prior to genetic testing is very important,” said Dr. Quintana.

In many cases, genetic counseling may be beneficial because it offers patients some additional information and resources that help them understand not only the results of their genetic tests but also the consequences of their conditions.
 

Ultimately, Genetic Testing in Rare Diseases Requires All Stakeholders to Have Patience and Tenacity

Dr. Regier summarized some of the nuances of genetic testing in the rare disease community. “Families understand that you might not be able to make the diagnosis,” Dr. Regier said. “It is more important to them that you stay on the journey with them, even if there is not a diagnosis.”

Another critical element of the diagnostic voyage hinges on clinicians recognizing and honoring that every family ­— and patient — is different.

“Some families want to do testing while others want to take one thing at a time and start with symptom management,” Dr. Regier said. “Both of these approaches are good, and every family has the right to decide when and if genetic testing should be part of their diagnostic odyssey.”

Suggested Reading

Baynam G et al. Stigma Associated With Genetic Testing for Rare Diseases — Causes and Recommendations. Front Genet. 2024 Apr 4:15:1335768. doi: 10.3389/fgene.2024.1335768.

Marwaha S et al. A Guide for the Diagnosis of Rare and Undiagnosed Disease: Beyond the Exome. Genome Med. 2022 Feb 28;14(1):23. doi: 10.1186/s13073-022-01026-w.

Unlike conventional immunosuppression, treatments approved since 2017 are giving patients with myasthenia gravis targeted options to better match their needs, desires, and tolerance. Used appropriately, newer treatments can provide dramatic results faster and more safely than broad immunosuppressants. However, according to experts, payers’ willingness to cover costly new therapies remains a work in progress.

The availability of more effective treatments with fewer side effects has brought about a cultural shift, said James F. Howard, Jr, MD. “The physician’s goal now is for the patient to be symptom free with grade 1 or less adverse events. And patients are demanding freedom from all the side effects that our usual course of immune therapy produces.” Dr. Howard is professor of neurology, medicine and allied health and director of the Myasthenia Gravis Clinical Trials and Translational Research Program at the University of North Carolina at Chapel Hill.

courtesy University of North Carolina

The shift has been long in coming. Although myasthenia gravis was identified in the mid-1600s, it took more than 340 years to get the first drug approved specifically for the disorder.

Worldwide prevalence estimates vary widely, from less than 200,000 to 700,000 cases.^1,2 Pathophysiologically, myasthenia gravis stems from autoimmune destruction of neuromuscular junctions (NMJs), which transmit motor neuron impulses to muscle fibers.¹ Symptoms include variable skeletal muscle weakness that can range from mild and transient to life-threatening.

In approximately 80% of cases, autoimmune antibodies target the postsynaptic acetylcholine receptor (AChR). Additional autoimmune targets mainly include muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). However, around 10% of patients are seronegative, lacking autoantibodies detectable through conventional radioimmunoassays. Clinical disease does not always correspond with circulating antibody levels, and pathogenesis may require cooperation between multiple autoantibodies attacking the same target.³ Around 10% of MG cases are associated with thymomas.

Among myasthenia gravis treatments, immunosuppressants typically take 4-10 months to begin working and 18-36 months for maximum benefit. “Our new targeted therapies work within 1-2 weeks, with maximum improvement occurring somewhere between 8 and 12 weeks,” Dr. Howard said. Quick onset makes these drugs well suited for primary therapy in recalcitrant myasthenia gravis or as bridges to standard immunotherapy. Targeted drugs also appear to provide effective rescue therapy, although head-to-head studies are needed.
 

Complement Inhibition

In AChR antibody–positive myasthenia gravis, autoantibody binding with the postsynaptic AChR receptor activates complement to attack postsynaptic neuronal membrane. Complement inhibitors approved to date block activation of the terminal complement protein C5.

courtesy George Washington University

For many patients, complement inhibitors deliver dramatic results. Henry J. Kaminski, MD, said that the first patient for whom he prescribed a complement inhibitor outside a clinical trial went from being miserable to traveling internationally within a month. Dr. Kaminski is Meta A. Neumann Professor of Neurology at George Washington University, Washington, DC. 

Eculizumab (Soliris, Alexion), earned Food and Drug Administration (FDA) approval for myasthenia gravis in 2017. Week 26 results in the phase 3 REGAIN trial showed no significant difference in Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores between treatment and placebo. However, said Dr. Howard, primary investigator on the study, the negative result was a statistical aberration stemming from the FDA’s requirement to use worst-rank analysis rather than absolute change scores. What got eculizumab approved were highly positive results in the overwhelming majority of secondary endpoints.⁴ Subsequently, the FDA had the manufacturer rewrite the package insert using common statistical methods, which yielded positive primary results.

Ravulizumab (Ultomiris, Alexion), approved for myasthenia gravis in 2022, reduces eculizumab’s twice-monthly intravenous dosing to every 2 months (after loading doses), with very similar efficacy. The newest complement inhibitor, zilucoplan (Zilbrysq, UCB), administered once daily subcutaneously, earned FDA approval in 2023. Daily subcutaneous dosing provides patient convenience, said Dr. Howard. Because the body does not clear this small molecule as it would a full-size antibody, it is the only complement inhibitor that can be combined with a fragment crystallizable neonatal receptor (FcRn) inhibitor.
 

FcRn Inhibition

The FcRn exists on the surface and intracellular vesicles of many cells, including B cells, but not T cells.⁵FcRn inhibitors block binding of circulating IgG antibodies to the FcRn, preventing their normal recycling, significantly reducing circulating antibodies within days of treatment.

Efgartigimod (Vyvgart, Argenx), earned FDA approval in intravenous form in 2021, followed by a subcutaneous formulation that includes hyaluronidase (Vyvgart Hytrulo) in 2023. Rozanolixizumab (Rystiggo, UCB) earned FDA approval for both AChR antibody–positive and MuSK antibody–positive myasthenia gravis in 2023.

Along with rapid response, said Dr. Howard, complement inhibitors and FcRn inhibitors offer a “hugely improved” side-effect profile. In phase 3 research, the most common side effects for both classes included headache, nausea, and diarrhea.^4,6,7 Because complement inhibitors increase the risk of Neisseria infection, users require immunization against meningococcal infection (or concurrent antibiotic prophylaxis) while on complement inhibitors.
 

Insurance Issues

With many clinicians wondering which targeted therapy to choose for a particular patient, said Dr. Howard and Dr. Kaminski, the main obstacle to wider use of these treatments is payer attitudes and practices. “While many of us would like to see these drugs used earlier in the course of disease,” Dr. Howard explained, “there are numerous restrictions placed on the physician and the patient by whatever insurance the individual has.”

Dr. Kaminski said: “There’s a lot of variability among insurance companies regarding what is expected in terms of getting approval for a certain medication. It frustrates me, thinking this patient may do well with a complement inhibitor or an FcRn inhibitor, but it takes weeks to get them approved.”

Some of his patients have been approved for, and flourished on, complement inhibitors and FcRn inhibitors, he added, and then denied a second round of treatment. Dr. Kaminski said he does not know why these patients were denied, and every time he requests reevaluation, the decision is reversed. “That’s a significant time frame for me and my staff to manage.”

When asked what can be done to address high drug prices, Dr. Howard replied, “I have no idea. I’m not an advocate of high drug prices. But I don’t think people realize the cost of doing clinical trials, which is hundreds of millions of dollars, particularly in rare diseases.”

Presently, Dr. Howard said, FcRn inhibitors are used more frequently than complement inhibitors solely because of cost. Zilucoplan will be priced below existing complement inhibitors, although it is too soon to compare its price with those of FcRn inhibitors.

When eculizumab debuted, said Dr. Howard, it cost nearly $750,000 annually. “But if you look at the number of patients treated, the cost of the drug over this population is probably less than the cost for using a cholesterol-lowering agent to treat hyperlipidemia.”

An Institute for Clinical and Economic Review (ICER) report stated that eculizumab and efgartigimod should both cost less than $20,000 annually to meet commonly used cost-effectiveness thresholds.⁸ However, Dr. Howard said ICER used models based on common diseases and ignored the economic impact of patients’ losing fewer workdays and avoiding long-term immunosuppressant side effects such as diabetes and osteoporosis and related treatment costs. “We’ve got to start looking at total societal cost,” he said.

Leapfrogging Ahead

Not all the new drugs work in every indicated patient, Dr. Howard said. For example, up to 30% of patients do not respond to complement inhibitors. “We don’t understand why. It’s as if we have leapfrogged way ahead in terms of therapeutics, and now we have to go back and answer all the questions – the who, what, where, and why of an individual drug and its response in folks.”

In this climate, said Dr. Kaminski, heavy direct-to-consumer advertising of newer myasthenia gravis therapies creates complications. “My patients are highly excited to see, ‘that’s my disease being advertised on Jeopardy.’ ” Many patients are frustrated with the general lack of awareness regarding myasthenia gravis, he added. “But then I’ve had patients who clearly would never qualify for a certain medication getting mailings to their homes.”

Dr. Howard countered that broader awareness of myasthenia gravis can only help. “There’s increasing recognition of the disease, not only by patients, but to some extent, by the treating clinician. Patients are coming to our offices and saying, ‘am I a candidate for this new drug?’ It’s the responsibility of the clinician to decide.”

Individual physicians’ practice patterns vary greatly, said Dr. Kaminski, and very little quantitative data exist here. But based on personal communications, academic-center neurologists tend to use targeted treatments on patients who have failed conventional treatments.

Conversely, Dr. Howard said that, because community physicians rarely see myasthenia gravis, and targeted treatments remain relatively new, many of these providers rely on prednisone, azathioprine, and mycophenolate mofetil.
 

B-Cell Blockers in Development

Overall, said Dr. Howard, the field of myasthenia gravis treatment development is “very rich. And pharma’s interest in myasthenia has taken off like a rocket. It’s exceptionally gratifying to those of us who take care of these patients whose life is miserable” because of adverse effects and/or nonresponse to current drugs.

“In myasthenia,” added Dr. Kaminski, “we know that T cells are promoting the activity of these auto-reactive B cells.” Many drugs currently in phase 2 or 3 development aim to eliminate B cells or signaling between T and B cells, he said. “That’s where most of the drug development is.”

Leading candidates include telitacicept (Tai’ai, RemeGen), which is both a B-lymphocyte stimulator and a proliferation-inducing ligand. A phase 3 trial (NCT05737160) is ongoing, with primary completion expected in late 2026. A second phase 3 trial (NCT06456580) recently began enrolling. Dr. Howard said that, although early results warranted phase 3 analysis, telitacicept’s phase 2 trial was open label and lacked a placebo group.⁹ The latter is a critical concern because placebo response rates in myasthenia gravis trials average 35%-40%.

Combined with standard care, the FcRn inhibitor nipocalimab (Johnson & Johnson) enabled patients with AChR, MuSK, and/or LRP4 autoantibodies to improve by 4.70 points on the MG-ADL vs 3.25 points for placebo (P = .002) over 24 weeks in phase ^3.10All FcRn inhibitors in development can broadly reduce autoantibody levels, said Dr. Howard. “But what role they will play in myasthenia gravis when they’re several years behind leaders in the field in terms of capturing market remains to be seen.”

Additionally, batoclimab (Immunovant/Harbour BioMed) showed positive topline results in phase 3, and an elevated rate of hypercholesterolemia in treated patients that was transient and consistent with previous research.¹¹ Subsequent to efgartigimod, Dr. Howard said, FcRn inhibitors are full-size antibodies. “I believe that contributes to the adverse events that we see. Efgartigimod is a small FcRn fragment. That’s why it’s a cleaner drug, if you will.”

FcRn inhibitors require periodic retreatment. For example, said Dr. Howard, the ADAPT phase 3 trial of efgartigimod, on which he was lead investigator, employed a cyclic dosing schedule – 4 weeks’ treatment, then observation until patients needed retreatment — because patients demanded it.¹² In clinical practice, some patients have gone more than 25 weeks before needing retreatment. One of his patients went beyond 40 weeks. “Others only get around 6-9 weeks. So patient choice again enters the decision-making process.”

Rituximab targets the CD20 protein on B cells nonspecifically, producing general immunosuppression. “That’s problematic in producing significant immunosuppression,” said Dr. Kaminski. Nevertheless, he said, rituximab is very effective for most patients with MuSK-specific MG, and its application to this indication has revealed differences between the MuSK subtype and AChR antibody–positive myasthenia. Specifically, MuSK antibody–positive patients have short-lived plasmablasts, which rituximab eliminates.¹³

Conversely, said Dr. Kaminski, patients with AChR antibody-positive myasthenia, especially long-term, likely have long-lived plasmablasts producing antibodies. This fact, and these patients’ lack of CD20, likely explain their poor response to rituximab.

A phase 3 trial (NCT04524273) of the CD19 blocker inebilizumab (Uplinza, Amgen) reached primary completion in May. Dr. Howard said that if topline results (unreleased at press time) prove positive, inebilizumab could replace rituximab in MG — provided payers do not reject inebilizumab because of cost.

Packed Early-Development Pipeline

Regarding early-stage projects, said Dr. Howard, the pipeline is packed with compounds that target various aspects of the immune system. “The real question with those is, what’s going to be the side effect profile? All of the trials are very early. We need bigger trials with much longer observation for safety, durability, and degree of efficacy.”

The next potential B cell–targeting game changer, he said, is chimeric antigen receptor (CAR) T cell–based therapy. In a phase 2b trial of Descartes-08 (Cartesian Therapeutics), 71% of treated patients experienced clinically meaningful improvement in MG Composite score at 3 months vs 25% for placebo.¹⁴

In early clinical trials, said Dr. Howard, patients treated with Descartes-08 — which uses autologous mRNA to target B-cell maturation antigen — have shown “exceptional improvement” lasting 20 or more months. Because the drug is not ingrained permanently into the genome, Descartes-08 avoids potentially severe side effects of DNA-targeting CAR T candidates. Dr. Howard hopes a phase 3 trial will commence around January 2025.

The tolerance approach exemplified by CNP-106 (COUR Pharmaceuticals) and a myasthenia gravis tolerogen (Toleranzia) seeks to prevent the immune system from recognizing and reacting to the NMJ abnormalities that produce myasthenia gravis, potentially providing a cure. “We look forward to those trials as they come online in the next 1-2 years,” said Dr. Howard.
 

Unmet Needs

Historically, neurologists believed that all myasthenia gravis symptoms stemmed from muscle fatigue — the more active the muscle, the weaker it gets. However, said Dr. Kaminski, some patients might lack measurable weakness but still complain of fatigue.

Elevated levels of cytokines such as interleukin (IL)–6 or IL-17 also can produce fatigue, he noted. “With the drugs we’re using, certainly the new ones, we’re not specifically targeting this fatigue phenomenon, which has been studied in a very limited fashion.”

In the RAISE-XT zilucoplan trial, participants experienced significant improvement in fatigue scores for up to 60 weeks.¹⁵ Although zilucoplan does not address fatigue directly, said Dr. Howard, improving myasthenia gravis overall helps reduce fatigue.

The Myasthenia Gravis Symptoms Patient Reported Outcome (MG Symptoms PRO), which Dr. Kaminski helped develop, includes questions designed to distinguish muscular fatigue from overall physical fatigue.¹⁶ “I’m very interested in some of the information that’s coming out on long COVID and its effect on muscle,” Dr. Kaminski added. “We might be able to learn from there that there’s still some pathology going on beyond the neuromuscular junction.”

What the field desperately needs, said Dr. Howard, are biomarkers to identify which patients will and will not respond to certain therapeutics. “We’re not there yet.” Such biomarkers are at least 3-7 years from becoming clinical reality.

Promising antibody-independent serum markers include circulating microRNAs. For example, miRNA-150-5p and miRNA-21-5p are elevated in generalized AChR-positive myasthenia gravis and early-onset myasthenia gravis (occurring before age 50) and decline after immunosuppression and thymectomy.¹⁷

Among diagnostic modalities for patients with seronegative myasthenia gravis, said Dr. Kaminski, single-fiber EMG is the most sensitive, at approximately 95%. “It’s not perfect.” Moreover, he said, performing this test accurately requires a highly experienced expert, which many treatment centers lack.

Presently, added Dr. Kaminski, orbital MRI is neither specific nor sensitive enough to be clinically useful. “One needs to be careful with these specialized tests that are published from the best laboratory in the world that does the test, and does it repetitively.” As the search for effective myasthenia gravis biomarkers continues, avoiding false-positive results is as important as avoiding false negatives.

References

1. Bubuioc AM et al. J Med Life. 2021 Jan-Mar;14(1):7-16. doi: 10.25122/jml-2020-0145.

2. Deenen JC et al. J Neuromuscul Dis. 2015;2(1):73-85. doi: 10.3233/JND-140045.

3. Kaminski HJ et al. J Clin Invest. 2024 Jun 17;134(12):e179742. doi: 10.1172/JCI179742.

4. Howard JF Jr et al. Lancet Neurol. 2017 Dec;16(12):976-986. doi: 10.1016/S1474-4422(17)30369-1.

5. Huda R. Front Immunol. 2020 Feb 21:11:240. doi: 10.3389/fimmu.2020.00240.

6. Howard JF Jr et al. Lancet Neurol. 2023 May;22(5):395-406. doi: 10.1016/S1474-4422(23)00080-7.

7. Vu T et al. NEJM Evid. 2022 May;1(5):EVIDoa2100066. doi: 10.1056/EVIDoa2100066.

8. Tice JA et al. October 20, 2021. https://icer.org/assessment/myasthenia-gravis/.

9. Yin J et al. Eur J Neurol. 2024 Aug;31(8):e16322. doi: 10.1111/ene.16322.

10. Antozzi C et al. EAN 2024, Abstract EPR-116. https://www.neurology.org/doi/10.1212/WNL.0000000000203660.

11. Yan C et al. JAMA Neurol. 2024 Mar 4;81(4):336-345. doi: 10.1001/jamaneurol.2024.0044.

12. Howard JF Jr et al. Lancet Neurol. 2021 Jul;20(7):526-536. doi: 10.1016/S1474-4422(21)00159-9.

13. Stathopoulos P et al. JCI Insight. 2017 Sep 7;2(17):e94263. doi: 10.1172/jci.insight.94263.

14. Cartesian Therapeutics. Cartesian Therapeutics announces positive topline results from phase 2b trial of Descartes-08 in patients with myasthenia gravis. 2024 Jul 2. https://ir.cartesiantherapeutics.com/news-releases/news-release-details/cartesian-therapeutics-announces-positive-topline-results-phase.

15. Howard JF Jr et al. Ther Adv Neurol Disord. 2024 Apr 17:17:17562864241243186. doi: 10.1177/17562864241243186.

16. Cleanthous S et al. Orphanet J Rare Dis. 2021 Oct 30;16(1):457. doi: 10.1186/s13023-021-02064-0.

17. Sabre L et al. Front Immunol. 2020 Mar 4:11:213. doi: 10.3389/fimmu.2020.00213.

Unlike conventional immunosuppression, treatments approved since 2017 are giving patients with myasthenia gravis targeted options to better match their needs, desires, and tolerance. Used appropriately, newer treatments can provide dramatic results faster and more safely than broad immunosuppressants. However, according to experts, payers’ willingness to cover costly new therapies remains a work in progress.

The availability of more effective treatments with fewer side effects has brought about a cultural shift, said James F. Howard, Jr, MD. “The physician’s goal now is for the patient to be symptom free with grade 1 or less adverse events. And patients are demanding freedom from all the side effects that our usual course of immune therapy produces.” Dr. Howard is professor of neurology, medicine and allied health and director of the Myasthenia Gravis Clinical Trials and Translational Research Program at the University of North Carolina at Chapel Hill.

courtesy University of North Carolina

The shift has been long in coming. Although myasthenia gravis was identified in the mid-1600s, it took more than 340 years to get the first drug approved specifically for the disorder.

Worldwide prevalence estimates vary widely, from less than 200,000 to 700,000 cases.^1,2 Pathophysiologically, myasthenia gravis stems from autoimmune destruction of neuromuscular junctions (NMJs), which transmit motor neuron impulses to muscle fibers.¹ Symptoms include variable skeletal muscle weakness that can range from mild and transient to life-threatening.

In approximately 80% of cases, autoimmune antibodies target the postsynaptic acetylcholine receptor (AChR). Additional autoimmune targets mainly include muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). However, around 10% of patients are seronegative, lacking autoantibodies detectable through conventional radioimmunoassays. Clinical disease does not always correspond with circulating antibody levels, and pathogenesis may require cooperation between multiple autoantibodies attacking the same target.³ Around 10% of MG cases are associated with thymomas.

Among myasthenia gravis treatments, immunosuppressants typically take 4-10 months to begin working and 18-36 months for maximum benefit. “Our new targeted therapies work within 1-2 weeks, with maximum improvement occurring somewhere between 8 and 12 weeks,” Dr. Howard said. Quick onset makes these drugs well suited for primary therapy in recalcitrant myasthenia gravis or as bridges to standard immunotherapy. Targeted drugs also appear to provide effective rescue therapy, although head-to-head studies are needed.
 

Complement Inhibition

In AChR antibody–positive myasthenia gravis, autoantibody binding with the postsynaptic AChR receptor activates complement to attack postsynaptic neuronal membrane. Complement inhibitors approved to date block activation of the terminal complement protein C5.

courtesy George Washington University

For many patients, complement inhibitors deliver dramatic results. Henry J. Kaminski, MD, said that the first patient for whom he prescribed a complement inhibitor outside a clinical trial went from being miserable to traveling internationally within a month. Dr. Kaminski is Meta A. Neumann Professor of Neurology at George Washington University, Washington, DC. 

Eculizumab (Soliris, Alexion), earned Food and Drug Administration (FDA) approval for myasthenia gravis in 2017. Week 26 results in the phase 3 REGAIN trial showed no significant difference in Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores between treatment and placebo. However, said Dr. Howard, primary investigator on the study, the negative result was a statistical aberration stemming from the FDA’s requirement to use worst-rank analysis rather than absolute change scores. What got eculizumab approved were highly positive results in the overwhelming majority of secondary endpoints.⁴ Subsequently, the FDA had the manufacturer rewrite the package insert using common statistical methods, which yielded positive primary results.

Ravulizumab (Ultomiris, Alexion), approved for myasthenia gravis in 2022, reduces eculizumab’s twice-monthly intravenous dosing to every 2 months (after loading doses), with very similar efficacy. The newest complement inhibitor, zilucoplan (Zilbrysq, UCB), administered once daily subcutaneously, earned FDA approval in 2023. Daily subcutaneous dosing provides patient convenience, said Dr. Howard. Because the body does not clear this small molecule as it would a full-size antibody, it is the only complement inhibitor that can be combined with a fragment crystallizable neonatal receptor (FcRn) inhibitor.
 

FcRn Inhibition

The FcRn exists on the surface and intracellular vesicles of many cells, including B cells, but not T cells.⁵FcRn inhibitors block binding of circulating IgG antibodies to the FcRn, preventing their normal recycling, significantly reducing circulating antibodies within days of treatment.

Efgartigimod (Vyvgart, Argenx), earned FDA approval in intravenous form in 2021, followed by a subcutaneous formulation that includes hyaluronidase (Vyvgart Hytrulo) in 2023. Rozanolixizumab (Rystiggo, UCB) earned FDA approval for both AChR antibody–positive and MuSK antibody–positive myasthenia gravis in 2023.

Along with rapid response, said Dr. Howard, complement inhibitors and FcRn inhibitors offer a “hugely improved” side-effect profile. In phase 3 research, the most common side effects for both classes included headache, nausea, and diarrhea.^4,6,7 Because complement inhibitors increase the risk of Neisseria infection, users require immunization against meningococcal infection (or concurrent antibiotic prophylaxis) while on complement inhibitors.
 

Insurance Issues

With many clinicians wondering which targeted therapy to choose for a particular patient, said Dr. Howard and Dr. Kaminski, the main obstacle to wider use of these treatments is payer attitudes and practices. “While many of us would like to see these drugs used earlier in the course of disease,” Dr. Howard explained, “there are numerous restrictions placed on the physician and the patient by whatever insurance the individual has.”

Dr. Kaminski said: “There’s a lot of variability among insurance companies regarding what is expected in terms of getting approval for a certain medication. It frustrates me, thinking this patient may do well with a complement inhibitor or an FcRn inhibitor, but it takes weeks to get them approved.”

Some of his patients have been approved for, and flourished on, complement inhibitors and FcRn inhibitors, he added, and then denied a second round of treatment. Dr. Kaminski said he does not know why these patients were denied, and every time he requests reevaluation, the decision is reversed. “That’s a significant time frame for me and my staff to manage.”

When asked what can be done to address high drug prices, Dr. Howard replied, “I have no idea. I’m not an advocate of high drug prices. But I don’t think people realize the cost of doing clinical trials, which is hundreds of millions of dollars, particularly in rare diseases.”

Presently, Dr. Howard said, FcRn inhibitors are used more frequently than complement inhibitors solely because of cost. Zilucoplan will be priced below existing complement inhibitors, although it is too soon to compare its price with those of FcRn inhibitors.

When eculizumab debuted, said Dr. Howard, it cost nearly $750,000 annually. “But if you look at the number of patients treated, the cost of the drug over this population is probably less than the cost for using a cholesterol-lowering agent to treat hyperlipidemia.”

An Institute for Clinical and Economic Review (ICER) report stated that eculizumab and efgartigimod should both cost less than $20,000 annually to meet commonly used cost-effectiveness thresholds.⁸ However, Dr. Howard said ICER used models based on common diseases and ignored the economic impact of patients’ losing fewer workdays and avoiding long-term immunosuppressant side effects such as diabetes and osteoporosis and related treatment costs. “We’ve got to start looking at total societal cost,” he said.

Leapfrogging Ahead

Not all the new drugs work in every indicated patient, Dr. Howard said. For example, up to 30% of patients do not respond to complement inhibitors. “We don’t understand why. It’s as if we have leapfrogged way ahead in terms of therapeutics, and now we have to go back and answer all the questions – the who, what, where, and why of an individual drug and its response in folks.”

In this climate, said Dr. Kaminski, heavy direct-to-consumer advertising of newer myasthenia gravis therapies creates complications. “My patients are highly excited to see, ‘that’s my disease being advertised on Jeopardy.’ ” Many patients are frustrated with the general lack of awareness regarding myasthenia gravis, he added. “But then I’ve had patients who clearly would never qualify for a certain medication getting mailings to their homes.”

Dr. Howard countered that broader awareness of myasthenia gravis can only help. “There’s increasing recognition of the disease, not only by patients, but to some extent, by the treating clinician. Patients are coming to our offices and saying, ‘am I a candidate for this new drug?’ It’s the responsibility of the clinician to decide.”

Individual physicians’ practice patterns vary greatly, said Dr. Kaminski, and very little quantitative data exist here. But based on personal communications, academic-center neurologists tend to use targeted treatments on patients who have failed conventional treatments.

Conversely, Dr. Howard said that, because community physicians rarely see myasthenia gravis, and targeted treatments remain relatively new, many of these providers rely on prednisone, azathioprine, and mycophenolate mofetil.
 

B-Cell Blockers in Development

Overall, said Dr. Howard, the field of myasthenia gravis treatment development is “very rich. And pharma’s interest in myasthenia has taken off like a rocket. It’s exceptionally gratifying to those of us who take care of these patients whose life is miserable” because of adverse effects and/or nonresponse to current drugs.

“In myasthenia,” added Dr. Kaminski, “we know that T cells are promoting the activity of these auto-reactive B cells.” Many drugs currently in phase 2 or 3 development aim to eliminate B cells or signaling between T and B cells, he said. “That’s where most of the drug development is.”

Leading candidates include telitacicept (Tai’ai, RemeGen), which is both a B-lymphocyte stimulator and a proliferation-inducing ligand. A phase 3 trial (NCT05737160) is ongoing, with primary completion expected in late 2026. A second phase 3 trial (NCT06456580) recently began enrolling. Dr. Howard said that, although early results warranted phase 3 analysis, telitacicept’s phase 2 trial was open label and lacked a placebo group.⁹ The latter is a critical concern because placebo response rates in myasthenia gravis trials average 35%-40%.

Combined with standard care, the FcRn inhibitor nipocalimab (Johnson & Johnson) enabled patients with AChR, MuSK, and/or LRP4 autoantibodies to improve by 4.70 points on the MG-ADL vs 3.25 points for placebo (P = .002) over 24 weeks in phase ^3.10All FcRn inhibitors in development can broadly reduce autoantibody levels, said Dr. Howard. “But what role they will play in myasthenia gravis when they’re several years behind leaders in the field in terms of capturing market remains to be seen.”

Additionally, batoclimab (Immunovant/Harbour BioMed) showed positive topline results in phase 3, and an elevated rate of hypercholesterolemia in treated patients that was transient and consistent with previous research.¹¹ Subsequent to efgartigimod, Dr. Howard said, FcRn inhibitors are full-size antibodies. “I believe that contributes to the adverse events that we see. Efgartigimod is a small FcRn fragment. That’s why it’s a cleaner drug, if you will.”

FcRn inhibitors require periodic retreatment. For example, said Dr. Howard, the ADAPT phase 3 trial of efgartigimod, on which he was lead investigator, employed a cyclic dosing schedule – 4 weeks’ treatment, then observation until patients needed retreatment — because patients demanded it.¹² In clinical practice, some patients have gone more than 25 weeks before needing retreatment. One of his patients went beyond 40 weeks. “Others only get around 6-9 weeks. So patient choice again enters the decision-making process.”

Rituximab targets the CD20 protein on B cells nonspecifically, producing general immunosuppression. “That’s problematic in producing significant immunosuppression,” said Dr. Kaminski. Nevertheless, he said, rituximab is very effective for most patients with MuSK-specific MG, and its application to this indication has revealed differences between the MuSK subtype and AChR antibody–positive myasthenia. Specifically, MuSK antibody–positive patients have short-lived plasmablasts, which rituximab eliminates.¹³

Conversely, said Dr. Kaminski, patients with AChR antibody-positive myasthenia, especially long-term, likely have long-lived plasmablasts producing antibodies. This fact, and these patients’ lack of CD20, likely explain their poor response to rituximab.

A phase 3 trial (NCT04524273) of the CD19 blocker inebilizumab (Uplinza, Amgen) reached primary completion in May. Dr. Howard said that if topline results (unreleased at press time) prove positive, inebilizumab could replace rituximab in MG — provided payers do not reject inebilizumab because of cost.

Packed Early-Development Pipeline

Regarding early-stage projects, said Dr. Howard, the pipeline is packed with compounds that target various aspects of the immune system. “The real question with those is, what’s going to be the side effect profile? All of the trials are very early. We need bigger trials with much longer observation for safety, durability, and degree of efficacy.”

The next potential B cell–targeting game changer, he said, is chimeric antigen receptor (CAR) T cell–based therapy. In a phase 2b trial of Descartes-08 (Cartesian Therapeutics), 71% of treated patients experienced clinically meaningful improvement in MG Composite score at 3 months vs 25% for placebo.¹⁴

In early clinical trials, said Dr. Howard, patients treated with Descartes-08 — which uses autologous mRNA to target B-cell maturation antigen — have shown “exceptional improvement” lasting 20 or more months. Because the drug is not ingrained permanently into the genome, Descartes-08 avoids potentially severe side effects of DNA-targeting CAR T candidates. Dr. Howard hopes a phase 3 trial will commence around January 2025.

The tolerance approach exemplified by CNP-106 (COUR Pharmaceuticals) and a myasthenia gravis tolerogen (Toleranzia) seeks to prevent the immune system from recognizing and reacting to the NMJ abnormalities that produce myasthenia gravis, potentially providing a cure. “We look forward to those trials as they come online in the next 1-2 years,” said Dr. Howard.
 

Unmet Needs

Historically, neurologists believed that all myasthenia gravis symptoms stemmed from muscle fatigue — the more active the muscle, the weaker it gets. However, said Dr. Kaminski, some patients might lack measurable weakness but still complain of fatigue.

Elevated levels of cytokines such as interleukin (IL)–6 or IL-17 also can produce fatigue, he noted. “With the drugs we’re using, certainly the new ones, we’re not specifically targeting this fatigue phenomenon, which has been studied in a very limited fashion.”

In the RAISE-XT zilucoplan trial, participants experienced significant improvement in fatigue scores for up to 60 weeks.¹⁵ Although zilucoplan does not address fatigue directly, said Dr. Howard, improving myasthenia gravis overall helps reduce fatigue.

The Myasthenia Gravis Symptoms Patient Reported Outcome (MG Symptoms PRO), which Dr. Kaminski helped develop, includes questions designed to distinguish muscular fatigue from overall physical fatigue.¹⁶ “I’m very interested in some of the information that’s coming out on long COVID and its effect on muscle,” Dr. Kaminski added. “We might be able to learn from there that there’s still some pathology going on beyond the neuromuscular junction.”

What the field desperately needs, said Dr. Howard, are biomarkers to identify which patients will and will not respond to certain therapeutics. “We’re not there yet.” Such biomarkers are at least 3-7 years from becoming clinical reality.

Promising antibody-independent serum markers include circulating microRNAs. For example, miRNA-150-5p and miRNA-21-5p are elevated in generalized AChR-positive myasthenia gravis and early-onset myasthenia gravis (occurring before age 50) and decline after immunosuppression and thymectomy.¹⁷

Among diagnostic modalities for patients with seronegative myasthenia gravis, said Dr. Kaminski, single-fiber EMG is the most sensitive, at approximately 95%. “It’s not perfect.” Moreover, he said, performing this test accurately requires a highly experienced expert, which many treatment centers lack.

Presently, added Dr. Kaminski, orbital MRI is neither specific nor sensitive enough to be clinically useful. “One needs to be careful with these specialized tests that are published from the best laboratory in the world that does the test, and does it repetitively.” As the search for effective myasthenia gravis biomarkers continues, avoiding false-positive results is as important as avoiding false negatives.

References

1. Bubuioc AM et al. J Med Life. 2021 Jan-Mar;14(1):7-16. doi: 10.25122/jml-2020-0145.

2. Deenen JC et al. J Neuromuscul Dis. 2015;2(1):73-85. doi: 10.3233/JND-140045.

3. Kaminski HJ et al. J Clin Invest. 2024 Jun 17;134(12):e179742. doi: 10.1172/JCI179742.

4. Howard JF Jr et al. Lancet Neurol. 2017 Dec;16(12):976-986. doi: 10.1016/S1474-4422(17)30369-1.

5. Huda R. Front Immunol. 2020 Feb 21:11:240. doi: 10.3389/fimmu.2020.00240.

6. Howard JF Jr et al. Lancet Neurol. 2023 May;22(5):395-406. doi: 10.1016/S1474-4422(23)00080-7.

7. Vu T et al. NEJM Evid. 2022 May;1(5):EVIDoa2100066. doi: 10.1056/EVIDoa2100066.

8. Tice JA et al. October 20, 2021. https://icer.org/assessment/myasthenia-gravis/.

9. Yin J et al. Eur J Neurol. 2024 Aug;31(8):e16322. doi: 10.1111/ene.16322.

10. Antozzi C et al. EAN 2024, Abstract EPR-116. https://www.neurology.org/doi/10.1212/WNL.0000000000203660.

11. Yan C et al. JAMA Neurol. 2024 Mar 4;81(4):336-345. doi: 10.1001/jamaneurol.2024.0044.

12. Howard JF Jr et al. Lancet Neurol. 2021 Jul;20(7):526-536. doi: 10.1016/S1474-4422(21)00159-9.

13. Stathopoulos P et al. JCI Insight. 2017 Sep 7;2(17):e94263. doi: 10.1172/jci.insight.94263.

14. Cartesian Therapeutics. Cartesian Therapeutics announces positive topline results from phase 2b trial of Descartes-08 in patients with myasthenia gravis. 2024 Jul 2. https://ir.cartesiantherapeutics.com/news-releases/news-release-details/cartesian-therapeutics-announces-positive-topline-results-phase.

15. Howard JF Jr et al. Ther Adv Neurol Disord. 2024 Apr 17:17:17562864241243186. doi: 10.1177/17562864241243186.

16. Cleanthous S et al. Orphanet J Rare Dis. 2021 Oct 30;16(1):457. doi: 10.1186/s13023-021-02064-0.

17. Sabre L et al. Front Immunol. 2020 Mar 4:11:213. doi: 10.3389/fimmu.2020.00213.

Unlike conventional immunosuppression, treatments approved since 2017 are giving patients with myasthenia gravis targeted options to better match their needs, desires, and tolerance. Used appropriately, newer treatments can provide dramatic results faster and more safely than broad immunosuppressants. However, according to experts, payers’ willingness to cover costly new therapies remains a work in progress.

The availability of more effective treatments with fewer side effects has brought about a cultural shift, said James F. Howard, Jr, MD. “The physician’s goal now is for the patient to be symptom free with grade 1 or less adverse events. And patients are demanding freedom from all the side effects that our usual course of immune therapy produces.” Dr. Howard is professor of neurology, medicine and allied health and director of the Myasthenia Gravis Clinical Trials and Translational Research Program at the University of North Carolina at Chapel Hill.

courtesy University of North Carolina

The shift has been long in coming. Although myasthenia gravis was identified in the mid-1600s, it took more than 340 years to get the first drug approved specifically for the disorder.

Worldwide prevalence estimates vary widely, from less than 200,000 to 700,000 cases.^1,2 Pathophysiologically, myasthenia gravis stems from autoimmune destruction of neuromuscular junctions (NMJs), which transmit motor neuron impulses to muscle fibers.¹ Symptoms include variable skeletal muscle weakness that can range from mild and transient to life-threatening.

In approximately 80% of cases, autoimmune antibodies target the postsynaptic acetylcholine receptor (AChR). Additional autoimmune targets mainly include muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). However, around 10% of patients are seronegative, lacking autoantibodies detectable through conventional radioimmunoassays. Clinical disease does not always correspond with circulating antibody levels, and pathogenesis may require cooperation between multiple autoantibodies attacking the same target.³ Around 10% of MG cases are associated with thymomas.

Among myasthenia gravis treatments, immunosuppressants typically take 4-10 months to begin working and 18-36 months for maximum benefit. “Our new targeted therapies work within 1-2 weeks, with maximum improvement occurring somewhere between 8 and 12 weeks,” Dr. Howard said. Quick onset makes these drugs well suited for primary therapy in recalcitrant myasthenia gravis or as bridges to standard immunotherapy. Targeted drugs also appear to provide effective rescue therapy, although head-to-head studies are needed.
 

Complement Inhibition

In AChR antibody–positive myasthenia gravis, autoantibody binding with the postsynaptic AChR receptor activates complement to attack postsynaptic neuronal membrane. Complement inhibitors approved to date block activation of the terminal complement protein C5.

courtesy George Washington University

For many patients, complement inhibitors deliver dramatic results. Henry J. Kaminski, MD, said that the first patient for whom he prescribed a complement inhibitor outside a clinical trial went from being miserable to traveling internationally within a month. Dr. Kaminski is Meta A. Neumann Professor of Neurology at George Washington University, Washington, DC. 

Eculizumab (Soliris, Alexion), earned Food and Drug Administration (FDA) approval for myasthenia gravis in 2017. Week 26 results in the phase 3 REGAIN trial showed no significant difference in Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores between treatment and placebo. However, said Dr. Howard, primary investigator on the study, the negative result was a statistical aberration stemming from the FDA’s requirement to use worst-rank analysis rather than absolute change scores. What got eculizumab approved were highly positive results in the overwhelming majority of secondary endpoints.⁴ Subsequently, the FDA had the manufacturer rewrite the package insert using common statistical methods, which yielded positive primary results.

Ravulizumab (Ultomiris, Alexion), approved for myasthenia gravis in 2022, reduces eculizumab’s twice-monthly intravenous dosing to every 2 months (after loading doses), with very similar efficacy. The newest complement inhibitor, zilucoplan (Zilbrysq, UCB), administered once daily subcutaneously, earned FDA approval in 2023. Daily subcutaneous dosing provides patient convenience, said Dr. Howard. Because the body does not clear this small molecule as it would a full-size antibody, it is the only complement inhibitor that can be combined with a fragment crystallizable neonatal receptor (FcRn) inhibitor.
 

FcRn Inhibition

The FcRn exists on the surface and intracellular vesicles of many cells, including B cells, but not T cells.⁵FcRn inhibitors block binding of circulating IgG antibodies to the FcRn, preventing their normal recycling, significantly reducing circulating antibodies within days of treatment.

Efgartigimod (Vyvgart, Argenx), earned FDA approval in intravenous form in 2021, followed by a subcutaneous formulation that includes hyaluronidase (Vyvgart Hytrulo) in 2023. Rozanolixizumab (Rystiggo, UCB) earned FDA approval for both AChR antibody–positive and MuSK antibody–positive myasthenia gravis in 2023.

Along with rapid response, said Dr. Howard, complement inhibitors and FcRn inhibitors offer a “hugely improved” side-effect profile. In phase 3 research, the most common side effects for both classes included headache, nausea, and diarrhea.^4,6,7 Because complement inhibitors increase the risk of Neisseria infection, users require immunization against meningococcal infection (or concurrent antibiotic prophylaxis) while on complement inhibitors.
 

Insurance Issues

With many clinicians wondering which targeted therapy to choose for a particular patient, said Dr. Howard and Dr. Kaminski, the main obstacle to wider use of these treatments is payer attitudes and practices. “While many of us would like to see these drugs used earlier in the course of disease,” Dr. Howard explained, “there are numerous restrictions placed on the physician and the patient by whatever insurance the individual has.”

Dr. Kaminski said: “There’s a lot of variability among insurance companies regarding what is expected in terms of getting approval for a certain medication. It frustrates me, thinking this patient may do well with a complement inhibitor or an FcRn inhibitor, but it takes weeks to get them approved.”

Some of his patients have been approved for, and flourished on, complement inhibitors and FcRn inhibitors, he added, and then denied a second round of treatment. Dr. Kaminski said he does not know why these patients were denied, and every time he requests reevaluation, the decision is reversed. “That’s a significant time frame for me and my staff to manage.”

When asked what can be done to address high drug prices, Dr. Howard replied, “I have no idea. I’m not an advocate of high drug prices. But I don’t think people realize the cost of doing clinical trials, which is hundreds of millions of dollars, particularly in rare diseases.”

Presently, Dr. Howard said, FcRn inhibitors are used more frequently than complement inhibitors solely because of cost. Zilucoplan will be priced below existing complement inhibitors, although it is too soon to compare its price with those of FcRn inhibitors.

When eculizumab debuted, said Dr. Howard, it cost nearly $750,000 annually. “But if you look at the number of patients treated, the cost of the drug over this population is probably less than the cost for using a cholesterol-lowering agent to treat hyperlipidemia.”

An Institute for Clinical and Economic Review (ICER) report stated that eculizumab and efgartigimod should both cost less than $20,000 annually to meet commonly used cost-effectiveness thresholds.⁸ However, Dr. Howard said ICER used models based on common diseases and ignored the economic impact of patients’ losing fewer workdays and avoiding long-term immunosuppressant side effects such as diabetes and osteoporosis and related treatment costs. “We’ve got to start looking at total societal cost,” he said.

Leapfrogging Ahead

Not all the new drugs work in every indicated patient, Dr. Howard said. For example, up to 30% of patients do not respond to complement inhibitors. “We don’t understand why. It’s as if we have leapfrogged way ahead in terms of therapeutics, and now we have to go back and answer all the questions – the who, what, where, and why of an individual drug and its response in folks.”

In this climate, said Dr. Kaminski, heavy direct-to-consumer advertising of newer myasthenia gravis therapies creates complications. “My patients are highly excited to see, ‘that’s my disease being advertised on Jeopardy.’ ” Many patients are frustrated with the general lack of awareness regarding myasthenia gravis, he added. “But then I’ve had patients who clearly would never qualify for a certain medication getting mailings to their homes.”

Dr. Howard countered that broader awareness of myasthenia gravis can only help. “There’s increasing recognition of the disease, not only by patients, but to some extent, by the treating clinician. Patients are coming to our offices and saying, ‘am I a candidate for this new drug?’ It’s the responsibility of the clinician to decide.”

Individual physicians’ practice patterns vary greatly, said Dr. Kaminski, and very little quantitative data exist here. But based on personal communications, academic-center neurologists tend to use targeted treatments on patients who have failed conventional treatments.

Conversely, Dr. Howard said that, because community physicians rarely see myasthenia gravis, and targeted treatments remain relatively new, many of these providers rely on prednisone, azathioprine, and mycophenolate mofetil.
 

B-Cell Blockers in Development

Overall, said Dr. Howard, the field of myasthenia gravis treatment development is “very rich. And pharma’s interest in myasthenia has taken off like a rocket. It’s exceptionally gratifying to those of us who take care of these patients whose life is miserable” because of adverse effects and/or nonresponse to current drugs.

“In myasthenia,” added Dr. Kaminski, “we know that T cells are promoting the activity of these auto-reactive B cells.” Many drugs currently in phase 2 or 3 development aim to eliminate B cells or signaling between T and B cells, he said. “That’s where most of the drug development is.”

Leading candidates include telitacicept (Tai’ai, RemeGen), which is both a B-lymphocyte stimulator and a proliferation-inducing ligand. A phase 3 trial (NCT05737160) is ongoing, with primary completion expected in late 2026. A second phase 3 trial (NCT06456580) recently began enrolling. Dr. Howard said that, although early results warranted phase 3 analysis, telitacicept’s phase 2 trial was open label and lacked a placebo group.⁹ The latter is a critical concern because placebo response rates in myasthenia gravis trials average 35%-40%.

Combined with standard care, the FcRn inhibitor nipocalimab (Johnson & Johnson) enabled patients with AChR, MuSK, and/or LRP4 autoantibodies to improve by 4.70 points on the MG-ADL vs 3.25 points for placebo (P = .002) over 24 weeks in phase ^3.10All FcRn inhibitors in development can broadly reduce autoantibody levels, said Dr. Howard. “But what role they will play in myasthenia gravis when they’re several years behind leaders in the field in terms of capturing market remains to be seen.”

Additionally, batoclimab (Immunovant/Harbour BioMed) showed positive topline results in phase 3, and an elevated rate of hypercholesterolemia in treated patients that was transient and consistent with previous research.¹¹ Subsequent to efgartigimod, Dr. Howard said, FcRn inhibitors are full-size antibodies. “I believe that contributes to the adverse events that we see. Efgartigimod is a small FcRn fragment. That’s why it’s a cleaner drug, if you will.”

FcRn inhibitors require periodic retreatment. For example, said Dr. Howard, the ADAPT phase 3 trial of efgartigimod, on which he was lead investigator, employed a cyclic dosing schedule – 4 weeks’ treatment, then observation until patients needed retreatment — because patients demanded it.¹² In clinical practice, some patients have gone more than 25 weeks before needing retreatment. One of his patients went beyond 40 weeks. “Others only get around 6-9 weeks. So patient choice again enters the decision-making process.”

Rituximab targets the CD20 protein on B cells nonspecifically, producing general immunosuppression. “That’s problematic in producing significant immunosuppression,” said Dr. Kaminski. Nevertheless, he said, rituximab is very effective for most patients with MuSK-specific MG, and its application to this indication has revealed differences between the MuSK subtype and AChR antibody–positive myasthenia. Specifically, MuSK antibody–positive patients have short-lived plasmablasts, which rituximab eliminates.¹³

Conversely, said Dr. Kaminski, patients with AChR antibody-positive myasthenia, especially long-term, likely have long-lived plasmablasts producing antibodies. This fact, and these patients’ lack of CD20, likely explain their poor response to rituximab.

A phase 3 trial (NCT04524273) of the CD19 blocker inebilizumab (Uplinza, Amgen) reached primary completion in May. Dr. Howard said that if topline results (unreleased at press time) prove positive, inebilizumab could replace rituximab in MG — provided payers do not reject inebilizumab because of cost.

Packed Early-Development Pipeline

Regarding early-stage projects, said Dr. Howard, the pipeline is packed with compounds that target various aspects of the immune system. “The real question with those is, what’s going to be the side effect profile? All of the trials are very early. We need bigger trials with much longer observation for safety, durability, and degree of efficacy.”

The next potential B cell–targeting game changer, he said, is chimeric antigen receptor (CAR) T cell–based therapy. In a phase 2b trial of Descartes-08 (Cartesian Therapeutics), 71% of treated patients experienced clinically meaningful improvement in MG Composite score at 3 months vs 25% for placebo.¹⁴

In early clinical trials, said Dr. Howard, patients treated with Descartes-08 — which uses autologous mRNA to target B-cell maturation antigen — have shown “exceptional improvement” lasting 20 or more months. Because the drug is not ingrained permanently into the genome, Descartes-08 avoids potentially severe side effects of DNA-targeting CAR T candidates. Dr. Howard hopes a phase 3 trial will commence around January 2025.

The tolerance approach exemplified by CNP-106 (COUR Pharmaceuticals) and a myasthenia gravis tolerogen (Toleranzia) seeks to prevent the immune system from recognizing and reacting to the NMJ abnormalities that produce myasthenia gravis, potentially providing a cure. “We look forward to those trials as they come online in the next 1-2 years,” said Dr. Howard.
 

Unmet Needs

Historically, neurologists believed that all myasthenia gravis symptoms stemmed from muscle fatigue — the more active the muscle, the weaker it gets. However, said Dr. Kaminski, some patients might lack measurable weakness but still complain of fatigue.

Elevated levels of cytokines such as interleukin (IL)–6 or IL-17 also can produce fatigue, he noted. “With the drugs we’re using, certainly the new ones, we’re not specifically targeting this fatigue phenomenon, which has been studied in a very limited fashion.”

In the RAISE-XT zilucoplan trial, participants experienced significant improvement in fatigue scores for up to 60 weeks.¹⁵ Although zilucoplan does not address fatigue directly, said Dr. Howard, improving myasthenia gravis overall helps reduce fatigue.

The Myasthenia Gravis Symptoms Patient Reported Outcome (MG Symptoms PRO), which Dr. Kaminski helped develop, includes questions designed to distinguish muscular fatigue from overall physical fatigue.¹⁶ “I’m very interested in some of the information that’s coming out on long COVID and its effect on muscle,” Dr. Kaminski added. “We might be able to learn from there that there’s still some pathology going on beyond the neuromuscular junction.”

What the field desperately needs, said Dr. Howard, are biomarkers to identify which patients will and will not respond to certain therapeutics. “We’re not there yet.” Such biomarkers are at least 3-7 years from becoming clinical reality.

Promising antibody-independent serum markers include circulating microRNAs. For example, miRNA-150-5p and miRNA-21-5p are elevated in generalized AChR-positive myasthenia gravis and early-onset myasthenia gravis (occurring before age 50) and decline after immunosuppression and thymectomy.¹⁷

Among diagnostic modalities for patients with seronegative myasthenia gravis, said Dr. Kaminski, single-fiber EMG is the most sensitive, at approximately 95%. “It’s not perfect.” Moreover, he said, performing this test accurately requires a highly experienced expert, which many treatment centers lack.

Presently, added Dr. Kaminski, orbital MRI is neither specific nor sensitive enough to be clinically useful. “One needs to be careful with these specialized tests that are published from the best laboratory in the world that does the test, and does it repetitively.” As the search for effective myasthenia gravis biomarkers continues, avoiding false-positive results is as important as avoiding false negatives.

References

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2. Deenen JC et al. J Neuromuscul Dis. 2015;2(1):73-85. doi: 10.3233/JND-140045.

3. Kaminski HJ et al. J Clin Invest. 2024 Jun 17;134(12):e179742. doi: 10.1172/JCI179742.

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8. Tice JA et al. October 20, 2021. https://icer.org/assessment/myasthenia-gravis/.

9. Yin J et al. Eur J Neurol. 2024 Aug;31(8):e16322. doi: 10.1111/ene.16322.

10. Antozzi C et al. EAN 2024, Abstract EPR-116. https://www.neurology.org/doi/10.1212/WNL.0000000000203660.

11. Yan C et al. JAMA Neurol. 2024 Mar 4;81(4):336-345. doi: 10.1001/jamaneurol.2024.0044.

12. Howard JF Jr et al. Lancet Neurol. 2021 Jul;20(7):526-536. doi: 10.1016/S1474-4422(21)00159-9.

13. Stathopoulos P et al. JCI Insight. 2017 Sep 7;2(17):e94263. doi: 10.1172/jci.insight.94263.

14. Cartesian Therapeutics. Cartesian Therapeutics announces positive topline results from phase 2b trial of Descartes-08 in patients with myasthenia gravis. 2024 Jul 2. https://ir.cartesiantherapeutics.com/news-releases/news-release-details/cartesian-therapeutics-announces-positive-topline-results-phase.

15. Howard JF Jr et al. Ther Adv Neurol Disord. 2024 Apr 17:17:17562864241243186. doi: 10.1177/17562864241243186.

16. Cleanthous S et al. Orphanet J Rare Dis. 2021 Oct 30;16(1):457. doi: 10.1186/s13023-021-02064-0.

17. Sabre L et al. Front Immunol. 2020 Mar 4:11:213. doi: 10.3389/fimmu.2020.00213.