User login
Promise for Disease-Modifying Therapies to Tame Huntington’s Disease
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.
In April 1872, The Medical and Surgical Reporter of Philadelphia published a roughly 3,000-word paper, titled “On Chorea,” by George Huntington, a 22-year-old family practice physician recently graduated from Columbia University, New York City.
“Chorea is essentially a disease of the nervous system. The name ‘chorea’ is given to the disease on account of the dancing propensities of those who are affected by it, and it is a very appropriate designation,” he wrote in the introduction.
Toward the end of the paper Dr. Huntington described a “hereditary chorea” that he had observed while on professional rounds with his father, also a physician, in towns on the eastern end of Long Island in New York.
“It is spoken of by those in whose veins the seeds of the disease are known to exist, with a kind of horror, and not at all alluded to except through dire necessity, when it is mentioned as ‘that disorder,’ ” he wrote, noting later that “I have never known a recovery or even an amelioration of symptoms in this form of chorea; when once it begins it clings to the bitter end.”1
It wasn’t until 1993 that a team of investigators identified the gene responsible for the neurodegenerative disorder we now know as Huntington’s disease.
That discovery sparked hope for better treatments and a cure, but progress over the last 31 years has been incremental. Nonetheless, recent intensive research into novel approaches for treating Huntington’s disease have considerably brightened prospects for patients and caregivers, experts say.
“This is a devastating neurodegenerative disease and in talking to families that I have had the privilege and honor of following, I hear from them that ‘in 1993 when the gene was identified and my family member — parent, grandparent, aunt, uncle — had Huntington’s, we thought that there would be a curative or disease-modifying therapy in no time,’ ” said Erin Furr Stimming, MD, FAAN, FANA professor of neurology and Memorial Hermann Endowed Chair at the McGovern Medical School at University of Texas Health Science Center in Houston.
“Here we are in 2024. I think our families are still so incredibly resilient and courageous, and they are willing and able to participate in clinical trials. Families in the Huntington’s disease community at large are really ready to have trials that do, in fact, demonstrate some evidence of slowing of disease progression. It’s an exciting time,” she said in an interview.
Repeating Nucleotides
Huntington’s disease is an autosomal dominant neurodegenerative disorder caused by an expansion of a CAG trinucleotide repeat in exon 1 of the huntingtin gene (HTT), which encodes for the huntingtin protein (HTT). The multiple repeats result in expanded expression of mutant HTT. The mutated protein disrupts normal cellular processes, alters intracellular calcium homeostasis, and interferes with gene transcription, leading to progressive degeneration of neurons, and to a hallmark Huntington’s disease triad consisting of movement disorders, cognitive decline, and mood/behavioral issues.
The number of repeats determines the severity of disease and the age of onset. In nonaffected persons the gene contains about 20 CAG repeats, but as genetics research dating from the 1990s has shown, a single HTT allele containing more than 40 CAG repeats will inevitably result in disease, whereas carriers with fewer than 36 repeats on both alleles will remain unaffected.2
The prevalence of the mutation in Western populations is estimated to be from 4 to 10 per 100,000.3
The disease usually manifests first in adults aged 30-50 years but may also occur in children or adolescents and young adults. Early symptoms often include a decline in executive function that may be noticeable to the patient’s family and friends, mood changes, and chorea.
“Because of the uncontrolled movements (chorea), a person with Huntington’s disease may lose a lot of weight without intending to, and may have trouble walking, balancing, and moving around safely. They will eventually lose the ability to work, drive, and manage tasks at home, and may qualify for disability benefits. Over time, the individual will develop difficulty with speaking and swallowing, and their movements will become slow and stiff. People with advanced Huntington’s disease need full-time care to help with their day-to-day activities, and they ultimately succumb to pneumonia, heart failure, or other complications,” according to the Huntington’s Disease Society of America.4
Managing Symptoms
say neurologists.
There are currently three medications approved for the treatment of chorea, all in the class of agents known as vesicular monoamine transporter 2 inhibitors. These agents are tetrabenazine (Xenazine, Lundbeck), deutetrabenazine (Austedo XR, Teva), and valbenazine (Ingrezza, Neurocrine Biosciences).
“These drugs can treat the chorea, but they also can help with some of the other motor features. For example, if a patient has chorea in the legs and you treat it, then maybe they’re walking will get better, or if they have chorea in the mouth and you treat the chorea, then maybe their speech and swallowing may improve,” Victor Sung, MD, professor of neurology and director of the Huntington’s Disease Clinic at the University of Alabama at Birmingham, said in an interview.
Mood and behavioral symptoms associated with Huntington’s disease – depression, anxiety, irritability, impulsivity, etc – can be managed with off-label use of antidepressants, mood stabilizers, and antipsychotic agents.
“When it comes to the cognitive symptoms, that’s a big gap where we don’t have anything that’s [Food and Drug Administration] approved for Huntington’s disease,” Dr. Sung said.
Agents used to treat Alzheimer’s disease, such as cholinesterase inhibitors and the glutamate receptor antagonist memantine, have been studied extensively for preservation of cognition in Huntington’s disease, but have not shown significant benefit.
Dr. Sung said that one promising approach to the problem of cognitive protection in Huntington’s disease is the investigational agent dalzanemdor (SAGE-718), an N-methyl-D-aspartic (NMDA) acid receptor positive allosteric modulator. The drug is in development for cognitive disorders associated with NMDA receptor dysfunction, including Huntington’s disease and Alzheimer’s disease.
In the phase 2 SURVEYOR trial, which was not powered to show efficacy of dalzanemdor over placebo, patients with Huntington’s disease reportedly tolerated the drug well, with treatment-related adverse events primarily mild or moderate in severity.
As of this writing dalzanemdor is being evaluated for efficacy, compared with placebo, in the phase 2 DIMENSION trial. The primary endpoint of this trial is a change from baseline in composite score of the Huntington’s Disease Cognitive Assessment Battery.
Disease-Modifying Therapies
As previously noted, although there is no cure for Huntington’s disease, neurology investigators are developing new strategies for delaying, stalling, or even preventing disease progression.
“There are so many different approaches, it’s hard to know where to start,” Christopher A. Ross, MD, director of the Huntington’s Disease Center at Johns Hopkins University in Baltimore, Maryland, said in an interview.
The most actively investigated approach may be huntingtin-lowering therapies, based on the supposition that mutant huntingtin protein (mHTT) is the primary toxin in Huntington’s disease.
“What you need to do is in some way lower it, and there are a number of different ways to do that: antinsense olignoclueotides, small interfering RNA, CRISPR Cas, or other gene-editing techniques, as well as gene therapy with an adenoviral vector” he said.
Gene Therapy
Dr. Ross cited as promising a phase 1/2 clinical trial of an investigational gene therapy, AMT-130 (uniQure), which consists of an adeno-associated virus vector and a gene encoding a microRNA that is designed to recognize, bind, and nonselectively lower both mHTT and wild-type HTT.
The compound is injected directly into the corpus striatum. It was demonstrated to decrease signs of Huntington’s disease in animal models, and interim data on 29 patients with Huntington’s disease followed for up to 24 months showed a statically significant, dose-dependent slowing of Huntington’s disease progression and lowering of neurofilament light protein, a marker for neuronal degeneration in Huntington’s disease, in cerebrospinal fluid (CSF).
AMT-130 targets exon 1 of the HTT gene, which appears to be an important target, Dr. Ross commented.
“The huntingtin protein is really big. The polyglutamine expansion, which is what causes the toxicity, is right at the N-terminus of exon 1, and there is increasingly good evidence that you can have an exon 1 misspliced protein product which causes the toxicity, so it may be especially important to lower Huntington by targeting exon 1,” he said.
Oral Splicing Modifier
PTC Therapeutics, based in New Jersey, is developing PTC518, an oral small molecule drug that can cross the blood-brain barrier and is reported to target mutant huntingtin protein.
The drug is a splicing modifier that promotes insertion of a premature stop codon to HTT mRNA, thereby degrading and lowering the HTT levels.5
In June 2024, the company reported that, in the phase 2a PIVOT-HD study of PTC518 in patients with Huntington’s disease, 12 months of treatment was associated with a dose-dependent lowering of mHTT in blood and CSF in an interim cohort.
“In addition, favorable trends were demonstrated on several relevant Huntington’s disease clinical assessments including Total Motor Score and Composite Unified Huntington’s Disease Rating Scale. Furthermore, following 12 months of treatment, PTC518 continues to be safe and well tolerated,” the company stated in a press release.
Antisense Oligonucleotides
Antisense oligonucleotides (ASOs) are short strands of DNA or RNA that bind to RNA sequences in faulty genes to modify production of target proteins.
One such drug, tominersen, developed jointly by Ionis and Roche, initially showed promise in a phase 1/2 trial for lowering mHTT in CSF without serious adverse events. But in a phase 3 trial, the intrathecally delivered agent was halted after an independent data monitoring committee recommended halting the trial, which Roche ended in 2021. The company reported in a letter to The New England Journal of Medicine that people in the high-dosage treatment group did measurably worse – although it remains unclear whether this was caused by excess protein lowering or an off-target effect.6 The tominersen program was the first to demonstrate that it was possible to lower HTT with an intervention, and the companies reported that they are continuing the agent’s development program.
Wave Life Sciences is developing an ASO, labeled WVE-003, designed to target a single-nucleotide polymorphism associated with the mHTT mRNA transcript within HTT. The company says that targeting the single-nucleotide polymorphism should allow lowering of expression of the mHTT will preserving wild-type HTT. This approach has the potential for therapies to prevent disease progression during the prodromal period, the company states.
Somatic Expansion
Dr. Furr Stimming and Dr. Ross both noted that there is considerable research interest into recently identified genetic modifiers that are believed to influence somatic instability, which in turn leads to somatic expansion.
“That seems to happen selectively in the neurons that are affected in Huntington’s disease. So a big puzzle for all of the neurodegenerative diseases is why are certain regions of the brain affected and other regions not? And it looks like, for the repeat expansion, this idea of somatic expansion seems to be increasingly central,” Dr. Ross said.
“The really exciting idea here is that, if somatic expansion is critical to the disease process and you could slow it down or stop it, you could go very early and potentially not just slow the progression of the disease once it starts, but conceivably even delay or possibly prevent the onset of Huntington’s disease,” he said.
Does HTT Lowering Mediate Progression?
“The next question is what does this mean clinically? Does lowering mutant huntingtin protein levels, and wild type for that matter, actually slow disease progression, which can be challenging to measure in a disease that is relatively slowly progressive?,” Dr. Furr Stimming said.
One important tool to help answer this question, she noted, is the Huntington’s Disease Integrated Staging System (HDISS), first described in 2022.7 The consensus-based system incorporates biological, clinical, and functional assessments, and characterizes patients from birth by stages, from stage 0 (persons who carry the mutation but have no detectable pathology), to stage 1 (measurable indicators of underlying pathophysiology), stage 2 (a detectable clinical phenotype), and finally to stage 3 (decline in function).
“The goal of the HDISS, which is designed for clinical research purposes, is to try to enroll individuals into clinical trials earlier rather than later, trying to get pharmaceutical companies and others to take advantage of the period prior to significant neurodegeneration occurring. Like Alzheimer’s disease and Parkinson’s disease, by the time we make a clinical diagnose significant neurodegeneration has occurred, so we really want to take advantage of the prodromal period to intervene with these potential disease-modifying therapies,” Dr. Furr Stimming said.
“At the end of the day, I suspect that we will not have just one effective disease-modifying therapy. I suspect that it will be a multifacted approach. We envision that we would hit the huntingtin protein from a few different angles. I envision that we would not only modify in some form or fashion production of the mutant huntingtin protein, but also try to influence the genetic modifiers that we think are important in somatic instability and expansion, which likely contributes to the rate of progression and symptom severity,” Dr. Furr Stimming said.
References
1. Huntington G. On Chorea. Reprinted in The Journal of Neuropsychiatry and Clinical Neurosciences. 2003;15(1):109-112. doi: 10.1176/jnp.15.1.109.
2. Kaemmerer WF and Grondin RC. Degener Neurol Neuromuscul Dis. 2019 Mar 8;9:3-17. doi: 10.2147/DNND.S163808.
3. Jimenez-Sanchez M et al. Cold Spring Harb Perspect Med. 2017 Jul 5;7(7):a024240. doi: 10.1101/cshperspect.a024240.
4. Huntington’s Disease Society of America. Overview of Huntington’s Disease. https://hdsa.org/what-is-hd/overview-of-huntingtons-disease/.
5. Beers B et al. J Neurol Neurosurg Psychiatry. 2022;93:A96. https://jnnp.bmj.com/content/93/Suppl_1/A96.1.
6. McColgan P et al. N Engl J Med. 2023 Dec 7;389(23):2203-2205. doi: 10.1056/NEJMc2300400.
7. Tabrizi SJ et al. Lancet Neurol. 2022 Jul;21(7):632-644. doi: 10.1016/S1474-4422(22)00120-X.
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.
In April 1872, The Medical and Surgical Reporter of Philadelphia published a roughly 3,000-word paper, titled “On Chorea,” by George Huntington, a 22-year-old family practice physician recently graduated from Columbia University, New York City.
“Chorea is essentially a disease of the nervous system. The name ‘chorea’ is given to the disease on account of the dancing propensities of those who are affected by it, and it is a very appropriate designation,” he wrote in the introduction.
Toward the end of the paper Dr. Huntington described a “hereditary chorea” that he had observed while on professional rounds with his father, also a physician, in towns on the eastern end of Long Island in New York.
“It is spoken of by those in whose veins the seeds of the disease are known to exist, with a kind of horror, and not at all alluded to except through dire necessity, when it is mentioned as ‘that disorder,’ ” he wrote, noting later that “I have never known a recovery or even an amelioration of symptoms in this form of chorea; when once it begins it clings to the bitter end.”1
It wasn’t until 1993 that a team of investigators identified the gene responsible for the neurodegenerative disorder we now know as Huntington’s disease.
That discovery sparked hope for better treatments and a cure, but progress over the last 31 years has been incremental. Nonetheless, recent intensive research into novel approaches for treating Huntington’s disease have considerably brightened prospects for patients and caregivers, experts say.
“This is a devastating neurodegenerative disease and in talking to families that I have had the privilege and honor of following, I hear from them that ‘in 1993 when the gene was identified and my family member — parent, grandparent, aunt, uncle — had Huntington’s, we thought that there would be a curative or disease-modifying therapy in no time,’ ” said Erin Furr Stimming, MD, FAAN, FANA professor of neurology and Memorial Hermann Endowed Chair at the McGovern Medical School at University of Texas Health Science Center in Houston.
“Here we are in 2024. I think our families are still so incredibly resilient and courageous, and they are willing and able to participate in clinical trials. Families in the Huntington’s disease community at large are really ready to have trials that do, in fact, demonstrate some evidence of slowing of disease progression. It’s an exciting time,” she said in an interview.
Repeating Nucleotides
Huntington’s disease is an autosomal dominant neurodegenerative disorder caused by an expansion of a CAG trinucleotide repeat in exon 1 of the huntingtin gene (HTT), which encodes for the huntingtin protein (HTT). The multiple repeats result in expanded expression of mutant HTT. The mutated protein disrupts normal cellular processes, alters intracellular calcium homeostasis, and interferes with gene transcription, leading to progressive degeneration of neurons, and to a hallmark Huntington’s disease triad consisting of movement disorders, cognitive decline, and mood/behavioral issues.
The number of repeats determines the severity of disease and the age of onset. In nonaffected persons the gene contains about 20 CAG repeats, but as genetics research dating from the 1990s has shown, a single HTT allele containing more than 40 CAG repeats will inevitably result in disease, whereas carriers with fewer than 36 repeats on both alleles will remain unaffected.2
The prevalence of the mutation in Western populations is estimated to be from 4 to 10 per 100,000.3
The disease usually manifests first in adults aged 30-50 years but may also occur in children or adolescents and young adults. Early symptoms often include a decline in executive function that may be noticeable to the patient’s family and friends, mood changes, and chorea.
“Because of the uncontrolled movements (chorea), a person with Huntington’s disease may lose a lot of weight without intending to, and may have trouble walking, balancing, and moving around safely. They will eventually lose the ability to work, drive, and manage tasks at home, and may qualify for disability benefits. Over time, the individual will develop difficulty with speaking and swallowing, and their movements will become slow and stiff. People with advanced Huntington’s disease need full-time care to help with their day-to-day activities, and they ultimately succumb to pneumonia, heart failure, or other complications,” according to the Huntington’s Disease Society of America.4
Managing Symptoms
say neurologists.
There are currently three medications approved for the treatment of chorea, all in the class of agents known as vesicular monoamine transporter 2 inhibitors. These agents are tetrabenazine (Xenazine, Lundbeck), deutetrabenazine (Austedo XR, Teva), and valbenazine (Ingrezza, Neurocrine Biosciences).
“These drugs can treat the chorea, but they also can help with some of the other motor features. For example, if a patient has chorea in the legs and you treat it, then maybe they’re walking will get better, or if they have chorea in the mouth and you treat the chorea, then maybe their speech and swallowing may improve,” Victor Sung, MD, professor of neurology and director of the Huntington’s Disease Clinic at the University of Alabama at Birmingham, said in an interview.
Mood and behavioral symptoms associated with Huntington’s disease – depression, anxiety, irritability, impulsivity, etc – can be managed with off-label use of antidepressants, mood stabilizers, and antipsychotic agents.
“When it comes to the cognitive symptoms, that’s a big gap where we don’t have anything that’s [Food and Drug Administration] approved for Huntington’s disease,” Dr. Sung said.
Agents used to treat Alzheimer’s disease, such as cholinesterase inhibitors and the glutamate receptor antagonist memantine, have been studied extensively for preservation of cognition in Huntington’s disease, but have not shown significant benefit.
Dr. Sung said that one promising approach to the problem of cognitive protection in Huntington’s disease is the investigational agent dalzanemdor (SAGE-718), an N-methyl-D-aspartic (NMDA) acid receptor positive allosteric modulator. The drug is in development for cognitive disorders associated with NMDA receptor dysfunction, including Huntington’s disease and Alzheimer’s disease.
In the phase 2 SURVEYOR trial, which was not powered to show efficacy of dalzanemdor over placebo, patients with Huntington’s disease reportedly tolerated the drug well, with treatment-related adverse events primarily mild or moderate in severity.
As of this writing dalzanemdor is being evaluated for efficacy, compared with placebo, in the phase 2 DIMENSION trial. The primary endpoint of this trial is a change from baseline in composite score of the Huntington’s Disease Cognitive Assessment Battery.
Disease-Modifying Therapies
As previously noted, although there is no cure for Huntington’s disease, neurology investigators are developing new strategies for delaying, stalling, or even preventing disease progression.
“There are so many different approaches, it’s hard to know where to start,” Christopher A. Ross, MD, director of the Huntington’s Disease Center at Johns Hopkins University in Baltimore, Maryland, said in an interview.
The most actively investigated approach may be huntingtin-lowering therapies, based on the supposition that mutant huntingtin protein (mHTT) is the primary toxin in Huntington’s disease.
“What you need to do is in some way lower it, and there are a number of different ways to do that: antinsense olignoclueotides, small interfering RNA, CRISPR Cas, or other gene-editing techniques, as well as gene therapy with an adenoviral vector” he said.
Gene Therapy
Dr. Ross cited as promising a phase 1/2 clinical trial of an investigational gene therapy, AMT-130 (uniQure), which consists of an adeno-associated virus vector and a gene encoding a microRNA that is designed to recognize, bind, and nonselectively lower both mHTT and wild-type HTT.
The compound is injected directly into the corpus striatum. It was demonstrated to decrease signs of Huntington’s disease in animal models, and interim data on 29 patients with Huntington’s disease followed for up to 24 months showed a statically significant, dose-dependent slowing of Huntington’s disease progression and lowering of neurofilament light protein, a marker for neuronal degeneration in Huntington’s disease, in cerebrospinal fluid (CSF).
AMT-130 targets exon 1 of the HTT gene, which appears to be an important target, Dr. Ross commented.
“The huntingtin protein is really big. The polyglutamine expansion, which is what causes the toxicity, is right at the N-terminus of exon 1, and there is increasingly good evidence that you can have an exon 1 misspliced protein product which causes the toxicity, so it may be especially important to lower Huntington by targeting exon 1,” he said.
Oral Splicing Modifier
PTC Therapeutics, based in New Jersey, is developing PTC518, an oral small molecule drug that can cross the blood-brain barrier and is reported to target mutant huntingtin protein.
The drug is a splicing modifier that promotes insertion of a premature stop codon to HTT mRNA, thereby degrading and lowering the HTT levels.5
In June 2024, the company reported that, in the phase 2a PIVOT-HD study of PTC518 in patients with Huntington’s disease, 12 months of treatment was associated with a dose-dependent lowering of mHTT in blood and CSF in an interim cohort.
“In addition, favorable trends were demonstrated on several relevant Huntington’s disease clinical assessments including Total Motor Score and Composite Unified Huntington’s Disease Rating Scale. Furthermore, following 12 months of treatment, PTC518 continues to be safe and well tolerated,” the company stated in a press release.
Antisense Oligonucleotides
Antisense oligonucleotides (ASOs) are short strands of DNA or RNA that bind to RNA sequences in faulty genes to modify production of target proteins.
One such drug, tominersen, developed jointly by Ionis and Roche, initially showed promise in a phase 1/2 trial for lowering mHTT in CSF without serious adverse events. But in a phase 3 trial, the intrathecally delivered agent was halted after an independent data monitoring committee recommended halting the trial, which Roche ended in 2021. The company reported in a letter to The New England Journal of Medicine that people in the high-dosage treatment group did measurably worse – although it remains unclear whether this was caused by excess protein lowering or an off-target effect.6 The tominersen program was the first to demonstrate that it was possible to lower HTT with an intervention, and the companies reported that they are continuing the agent’s development program.
Wave Life Sciences is developing an ASO, labeled WVE-003, designed to target a single-nucleotide polymorphism associated with the mHTT mRNA transcript within HTT. The company says that targeting the single-nucleotide polymorphism should allow lowering of expression of the mHTT will preserving wild-type HTT. This approach has the potential for therapies to prevent disease progression during the prodromal period, the company states.
Somatic Expansion
Dr. Furr Stimming and Dr. Ross both noted that there is considerable research interest into recently identified genetic modifiers that are believed to influence somatic instability, which in turn leads to somatic expansion.
“That seems to happen selectively in the neurons that are affected in Huntington’s disease. So a big puzzle for all of the neurodegenerative diseases is why are certain regions of the brain affected and other regions not? And it looks like, for the repeat expansion, this idea of somatic expansion seems to be increasingly central,” Dr. Ross said.
“The really exciting idea here is that, if somatic expansion is critical to the disease process and you could slow it down or stop it, you could go very early and potentially not just slow the progression of the disease once it starts, but conceivably even delay or possibly prevent the onset of Huntington’s disease,” he said.
Does HTT Lowering Mediate Progression?
“The next question is what does this mean clinically? Does lowering mutant huntingtin protein levels, and wild type for that matter, actually slow disease progression, which can be challenging to measure in a disease that is relatively slowly progressive?,” Dr. Furr Stimming said.
One important tool to help answer this question, she noted, is the Huntington’s Disease Integrated Staging System (HDISS), first described in 2022.7 The consensus-based system incorporates biological, clinical, and functional assessments, and characterizes patients from birth by stages, from stage 0 (persons who carry the mutation but have no detectable pathology), to stage 1 (measurable indicators of underlying pathophysiology), stage 2 (a detectable clinical phenotype), and finally to stage 3 (decline in function).
“The goal of the HDISS, which is designed for clinical research purposes, is to try to enroll individuals into clinical trials earlier rather than later, trying to get pharmaceutical companies and others to take advantage of the period prior to significant neurodegeneration occurring. Like Alzheimer’s disease and Parkinson’s disease, by the time we make a clinical diagnose significant neurodegeneration has occurred, so we really want to take advantage of the prodromal period to intervene with these potential disease-modifying therapies,” Dr. Furr Stimming said.
“At the end of the day, I suspect that we will not have just one effective disease-modifying therapy. I suspect that it will be a multifacted approach. We envision that we would hit the huntingtin protein from a few different angles. I envision that we would not only modify in some form or fashion production of the mutant huntingtin protein, but also try to influence the genetic modifiers that we think are important in somatic instability and expansion, which likely contributes to the rate of progression and symptom severity,” Dr. Furr Stimming said.
References
1. Huntington G. On Chorea. Reprinted in The Journal of Neuropsychiatry and Clinical Neurosciences. 2003;15(1):109-112. doi: 10.1176/jnp.15.1.109.
2. Kaemmerer WF and Grondin RC. Degener Neurol Neuromuscul Dis. 2019 Mar 8;9:3-17. doi: 10.2147/DNND.S163808.
3. Jimenez-Sanchez M et al. Cold Spring Harb Perspect Med. 2017 Jul 5;7(7):a024240. doi: 10.1101/cshperspect.a024240.
4. Huntington’s Disease Society of America. Overview of Huntington’s Disease. https://hdsa.org/what-is-hd/overview-of-huntingtons-disease/.
5. Beers B et al. J Neurol Neurosurg Psychiatry. 2022;93:A96. https://jnnp.bmj.com/content/93/Suppl_1/A96.1.
6. McColgan P et al. N Engl J Med. 2023 Dec 7;389(23):2203-2205. doi: 10.1056/NEJMc2300400.
7. Tabrizi SJ et al. Lancet Neurol. 2022 Jul;21(7):632-644. doi: 10.1016/S1474-4422(22)00120-X.
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.
In April 1872, The Medical and Surgical Reporter of Philadelphia published a roughly 3,000-word paper, titled “On Chorea,” by George Huntington, a 22-year-old family practice physician recently graduated from Columbia University, New York City.
“Chorea is essentially a disease of the nervous system. The name ‘chorea’ is given to the disease on account of the dancing propensities of those who are affected by it, and it is a very appropriate designation,” he wrote in the introduction.
Toward the end of the paper Dr. Huntington described a “hereditary chorea” that he had observed while on professional rounds with his father, also a physician, in towns on the eastern end of Long Island in New York.
“It is spoken of by those in whose veins the seeds of the disease are known to exist, with a kind of horror, and not at all alluded to except through dire necessity, when it is mentioned as ‘that disorder,’ ” he wrote, noting later that “I have never known a recovery or even an amelioration of symptoms in this form of chorea; when once it begins it clings to the bitter end.”1
It wasn’t until 1993 that a team of investigators identified the gene responsible for the neurodegenerative disorder we now know as Huntington’s disease.
That discovery sparked hope for better treatments and a cure, but progress over the last 31 years has been incremental. Nonetheless, recent intensive research into novel approaches for treating Huntington’s disease have considerably brightened prospects for patients and caregivers, experts say.
“This is a devastating neurodegenerative disease and in talking to families that I have had the privilege and honor of following, I hear from them that ‘in 1993 when the gene was identified and my family member — parent, grandparent, aunt, uncle — had Huntington’s, we thought that there would be a curative or disease-modifying therapy in no time,’ ” said Erin Furr Stimming, MD, FAAN, FANA professor of neurology and Memorial Hermann Endowed Chair at the McGovern Medical School at University of Texas Health Science Center in Houston.
“Here we are in 2024. I think our families are still so incredibly resilient and courageous, and they are willing and able to participate in clinical trials. Families in the Huntington’s disease community at large are really ready to have trials that do, in fact, demonstrate some evidence of slowing of disease progression. It’s an exciting time,” she said in an interview.
Repeating Nucleotides
Huntington’s disease is an autosomal dominant neurodegenerative disorder caused by an expansion of a CAG trinucleotide repeat in exon 1 of the huntingtin gene (HTT), which encodes for the huntingtin protein (HTT). The multiple repeats result in expanded expression of mutant HTT. The mutated protein disrupts normal cellular processes, alters intracellular calcium homeostasis, and interferes with gene transcription, leading to progressive degeneration of neurons, and to a hallmark Huntington’s disease triad consisting of movement disorders, cognitive decline, and mood/behavioral issues.
The number of repeats determines the severity of disease and the age of onset. In nonaffected persons the gene contains about 20 CAG repeats, but as genetics research dating from the 1990s has shown, a single HTT allele containing more than 40 CAG repeats will inevitably result in disease, whereas carriers with fewer than 36 repeats on both alleles will remain unaffected.2
The prevalence of the mutation in Western populations is estimated to be from 4 to 10 per 100,000.3
The disease usually manifests first in adults aged 30-50 years but may also occur in children or adolescents and young adults. Early symptoms often include a decline in executive function that may be noticeable to the patient’s family and friends, mood changes, and chorea.
“Because of the uncontrolled movements (chorea), a person with Huntington’s disease may lose a lot of weight without intending to, and may have trouble walking, balancing, and moving around safely. They will eventually lose the ability to work, drive, and manage tasks at home, and may qualify for disability benefits. Over time, the individual will develop difficulty with speaking and swallowing, and their movements will become slow and stiff. People with advanced Huntington’s disease need full-time care to help with their day-to-day activities, and they ultimately succumb to pneumonia, heart failure, or other complications,” according to the Huntington’s Disease Society of America.4
Managing Symptoms
say neurologists.
There are currently three medications approved for the treatment of chorea, all in the class of agents known as vesicular monoamine transporter 2 inhibitors. These agents are tetrabenazine (Xenazine, Lundbeck), deutetrabenazine (Austedo XR, Teva), and valbenazine (Ingrezza, Neurocrine Biosciences).
“These drugs can treat the chorea, but they also can help with some of the other motor features. For example, if a patient has chorea in the legs and you treat it, then maybe they’re walking will get better, or if they have chorea in the mouth and you treat the chorea, then maybe their speech and swallowing may improve,” Victor Sung, MD, professor of neurology and director of the Huntington’s Disease Clinic at the University of Alabama at Birmingham, said in an interview.
Mood and behavioral symptoms associated with Huntington’s disease – depression, anxiety, irritability, impulsivity, etc – can be managed with off-label use of antidepressants, mood stabilizers, and antipsychotic agents.
“When it comes to the cognitive symptoms, that’s a big gap where we don’t have anything that’s [Food and Drug Administration] approved for Huntington’s disease,” Dr. Sung said.
Agents used to treat Alzheimer’s disease, such as cholinesterase inhibitors and the glutamate receptor antagonist memantine, have been studied extensively for preservation of cognition in Huntington’s disease, but have not shown significant benefit.
Dr. Sung said that one promising approach to the problem of cognitive protection in Huntington’s disease is the investigational agent dalzanemdor (SAGE-718), an N-methyl-D-aspartic (NMDA) acid receptor positive allosteric modulator. The drug is in development for cognitive disorders associated with NMDA receptor dysfunction, including Huntington’s disease and Alzheimer’s disease.
In the phase 2 SURVEYOR trial, which was not powered to show efficacy of dalzanemdor over placebo, patients with Huntington’s disease reportedly tolerated the drug well, with treatment-related adverse events primarily mild or moderate in severity.
As of this writing dalzanemdor is being evaluated for efficacy, compared with placebo, in the phase 2 DIMENSION trial. The primary endpoint of this trial is a change from baseline in composite score of the Huntington’s Disease Cognitive Assessment Battery.
Disease-Modifying Therapies
As previously noted, although there is no cure for Huntington’s disease, neurology investigators are developing new strategies for delaying, stalling, or even preventing disease progression.
“There are so many different approaches, it’s hard to know where to start,” Christopher A. Ross, MD, director of the Huntington’s Disease Center at Johns Hopkins University in Baltimore, Maryland, said in an interview.
The most actively investigated approach may be huntingtin-lowering therapies, based on the supposition that mutant huntingtin protein (mHTT) is the primary toxin in Huntington’s disease.
“What you need to do is in some way lower it, and there are a number of different ways to do that: antinsense olignoclueotides, small interfering RNA, CRISPR Cas, or other gene-editing techniques, as well as gene therapy with an adenoviral vector” he said.
Gene Therapy
Dr. Ross cited as promising a phase 1/2 clinical trial of an investigational gene therapy, AMT-130 (uniQure), which consists of an adeno-associated virus vector and a gene encoding a microRNA that is designed to recognize, bind, and nonselectively lower both mHTT and wild-type HTT.
The compound is injected directly into the corpus striatum. It was demonstrated to decrease signs of Huntington’s disease in animal models, and interim data on 29 patients with Huntington’s disease followed for up to 24 months showed a statically significant, dose-dependent slowing of Huntington’s disease progression and lowering of neurofilament light protein, a marker for neuronal degeneration in Huntington’s disease, in cerebrospinal fluid (CSF).
AMT-130 targets exon 1 of the HTT gene, which appears to be an important target, Dr. Ross commented.
“The huntingtin protein is really big. The polyglutamine expansion, which is what causes the toxicity, is right at the N-terminus of exon 1, and there is increasingly good evidence that you can have an exon 1 misspliced protein product which causes the toxicity, so it may be especially important to lower Huntington by targeting exon 1,” he said.
Oral Splicing Modifier
PTC Therapeutics, based in New Jersey, is developing PTC518, an oral small molecule drug that can cross the blood-brain barrier and is reported to target mutant huntingtin protein.
The drug is a splicing modifier that promotes insertion of a premature stop codon to HTT mRNA, thereby degrading and lowering the HTT levels.5
In June 2024, the company reported that, in the phase 2a PIVOT-HD study of PTC518 in patients with Huntington’s disease, 12 months of treatment was associated with a dose-dependent lowering of mHTT in blood and CSF in an interim cohort.
“In addition, favorable trends were demonstrated on several relevant Huntington’s disease clinical assessments including Total Motor Score and Composite Unified Huntington’s Disease Rating Scale. Furthermore, following 12 months of treatment, PTC518 continues to be safe and well tolerated,” the company stated in a press release.
Antisense Oligonucleotides
Antisense oligonucleotides (ASOs) are short strands of DNA or RNA that bind to RNA sequences in faulty genes to modify production of target proteins.
One such drug, tominersen, developed jointly by Ionis and Roche, initially showed promise in a phase 1/2 trial for lowering mHTT in CSF without serious adverse events. But in a phase 3 trial, the intrathecally delivered agent was halted after an independent data monitoring committee recommended halting the trial, which Roche ended in 2021. The company reported in a letter to The New England Journal of Medicine that people in the high-dosage treatment group did measurably worse – although it remains unclear whether this was caused by excess protein lowering or an off-target effect.6 The tominersen program was the first to demonstrate that it was possible to lower HTT with an intervention, and the companies reported that they are continuing the agent’s development program.
Wave Life Sciences is developing an ASO, labeled WVE-003, designed to target a single-nucleotide polymorphism associated with the mHTT mRNA transcript within HTT. The company says that targeting the single-nucleotide polymorphism should allow lowering of expression of the mHTT will preserving wild-type HTT. This approach has the potential for therapies to prevent disease progression during the prodromal period, the company states.
Somatic Expansion
Dr. Furr Stimming and Dr. Ross both noted that there is considerable research interest into recently identified genetic modifiers that are believed to influence somatic instability, which in turn leads to somatic expansion.
“That seems to happen selectively in the neurons that are affected in Huntington’s disease. So a big puzzle for all of the neurodegenerative diseases is why are certain regions of the brain affected and other regions not? And it looks like, for the repeat expansion, this idea of somatic expansion seems to be increasingly central,” Dr. Ross said.
“The really exciting idea here is that, if somatic expansion is critical to the disease process and you could slow it down or stop it, you could go very early and potentially not just slow the progression of the disease once it starts, but conceivably even delay or possibly prevent the onset of Huntington’s disease,” he said.
Does HTT Lowering Mediate Progression?
“The next question is what does this mean clinically? Does lowering mutant huntingtin protein levels, and wild type for that matter, actually slow disease progression, which can be challenging to measure in a disease that is relatively slowly progressive?,” Dr. Furr Stimming said.
One important tool to help answer this question, she noted, is the Huntington’s Disease Integrated Staging System (HDISS), first described in 2022.7 The consensus-based system incorporates biological, clinical, and functional assessments, and characterizes patients from birth by stages, from stage 0 (persons who carry the mutation but have no detectable pathology), to stage 1 (measurable indicators of underlying pathophysiology), stage 2 (a detectable clinical phenotype), and finally to stage 3 (decline in function).
“The goal of the HDISS, which is designed for clinical research purposes, is to try to enroll individuals into clinical trials earlier rather than later, trying to get pharmaceutical companies and others to take advantage of the period prior to significant neurodegeneration occurring. Like Alzheimer’s disease and Parkinson’s disease, by the time we make a clinical diagnose significant neurodegeneration has occurred, so we really want to take advantage of the prodromal period to intervene with these potential disease-modifying therapies,” Dr. Furr Stimming said.
“At the end of the day, I suspect that we will not have just one effective disease-modifying therapy. I suspect that it will be a multifacted approach. We envision that we would hit the huntingtin protein from a few different angles. I envision that we would not only modify in some form or fashion production of the mutant huntingtin protein, but also try to influence the genetic modifiers that we think are important in somatic instability and expansion, which likely contributes to the rate of progression and symptom severity,” Dr. Furr Stimming said.
References
1. Huntington G. On Chorea. Reprinted in The Journal of Neuropsychiatry and Clinical Neurosciences. 2003;15(1):109-112. doi: 10.1176/jnp.15.1.109.
2. Kaemmerer WF and Grondin RC. Degener Neurol Neuromuscul Dis. 2019 Mar 8;9:3-17. doi: 10.2147/DNND.S163808.
3. Jimenez-Sanchez M et al. Cold Spring Harb Perspect Med. 2017 Jul 5;7(7):a024240. doi: 10.1101/cshperspect.a024240.
4. Huntington’s Disease Society of America. Overview of Huntington’s Disease. https://hdsa.org/what-is-hd/overview-of-huntingtons-disease/.
5. Beers B et al. J Neurol Neurosurg Psychiatry. 2022;93:A96. https://jnnp.bmj.com/content/93/Suppl_1/A96.1.
6. McColgan P et al. N Engl J Med. 2023 Dec 7;389(23):2203-2205. doi: 10.1056/NEJMc2300400.
7. Tabrizi SJ et al. Lancet Neurol. 2022 Jul;21(7):632-644. doi: 10.1016/S1474-4422(22)00120-X.
Genetic Testing for ALS, Now a Standard, Creates a Path Toward Individualized Care
The first therapy targeted at modifying a mutant gene associated with amyotrophic lateral sclerosis (ALS), approved in early 2023, has offered reassurance that the biology of ALS, when known, is targetable. Historically, the disease has been considered a clinical diagnosis, but the
Despite a narrow indication, the only therapy targeted at an ALS-associated gene so far, SOD1 ALS, supports the premise that the biology of ALS can be modified, according to Christina N. Fournier, MD, an associate professor in the Department of Neurology, Emory University, Atlanta, Georgia.
Rather than a single pathological entity, ALS is best understood as the end result of many different pathological processes. Each might require its own targeted therapy in order to interrupt the upstream biological pathways that drive disease.
About 15% of ALS Has An Identifiable Genetic Cause
A family history of ALS is present in about 10% of cases. A genetic cause can be identified in approximately 15%. Cases without an identifiable genetic etiology are considered sporadic. So far, the only approved therapy that modifies the function of a gene associated with ALS is tofersen (Qalsody, Biogen), an antisense oligonucleotide. Tofersen inhibits RNA transcription of the superoxide dismutase 1 (SOD1) gene to decrease production of the SOD1 protein.
This first gene therapy for ALS is a breakthrough, but it is indicated for only a small proportion of ALS patients. Even though SOD1 gene mutations represent the second most common genetic cause of ALS after the C90rf72 gene, the proportion of patients who are candidates for tofersen is low. Efficacy is expected only in about 1% of those with familial ALS and 1% of those with sporadic ALS, or about 2% of all patients with ALS.
The evidence of benefit from a treatment with a specific target has provided the basis for concluding that “we are onto something,” Dr. Fournier said. An expert in ALS, she sees reason for excitement about the prospects in treatment with the growing focus on the underlying pathways of disease rather than the downstream consequences.
“The hope is that new gene-targeted therapies will be developed in the future to treat the broader ALS population,” said Dr. Fournier, explaining that the move toward rationally targeted treatments, whether related to gene mutations or independent molecular pathways of ALS progression, has created excitement in the field.
Numerous Disease Processes Are Potentially Targetable
As treatments are developed to address nongenetic molecular processes that contribute to the risk or progression of ALS, such as neuroinflammation or abnormal protein misfolding and aggregation, individualized treatment is likely to become key. Just as not all genetic cases share mutations in the same gene, the key molecular drivers of disease are likely to differ between patients. If so, it is hoped that biomarkers reflective of this underlying biology can be identified to appropriately target treatments.
“The excitement behind the newer targets in clinical trials is based on both basic science and early clinical data that support treatment based on specific drivers of disease,” Dr. Fournier said.
In 2023 and just prior to the FDA approval of tofersen, a set of expert consensus guidelines were published calling for genetic testing to be offered to all patients with ALS. These recommendations suggested that SOD1, C9orf72, FUS, and TARDBP should be included routinely into the panel of genes evaluated, calling for additional genes to be added as they emerge as potential therapeutic targets.
Even before these guidelines were released, genetic testing was already being offered at many centers with expertise in ALS. The rationale was to differentiate ALS with a genetic etiology from that with a nongenetic etiology, as well as to counsel family members when genetic risk was identified, but genetic testing has now assumed new urgency. In addition to the potential for offering a specific treatment for SOD1-related ALS, patients with other genetic forms of disease might be candidates for genetically focused clinical trials.
Genetic testing should be performed as soon as a diagnosis of ALS is made, according to Dr. Fournier. Although not all patients have accepted genetic testing, particularly in the past when there was no immediate clinical gain from establishing the presence of a genetic mutation, she said there is no longer any controversy about clinical relevance.
Genetic Testing Is Key to Genetic Therapies
“We do not want to miss the opportunity to treat patients when we have the chance,” said Dr. Fournier, referring to both the likely advantage of an early start of the approved gene therapy as well as the opportunity to participate in a clinical trial with other gene therapies in development.
Prior to the approval of tofersen, riluzole and edaravone had been the only disease-modifying agents in widespread use, but these drugs are nonspecific. There are no established biomarkers for establishing which patients are most likely to benefit.
In the case of riluzole, a pivotal trial conducted 30 years ago showed a survival benefit relative to placebo at 12 months (74% vs. 58%; P = 0.014). In a retrospective study published in 2022 that evaluated survival in a database of 4778 ALS patients of whom 3446 received riluzole, early diagnosis of ALS and prompt treatment with riluzole was associated with longer survival than delayed treatment. The benefit of edaravone has been validated with clinical measures, such as the revised Amyotrophic Lateral Sclerosis Functional Scale (ALSFRS-R).
The retrospective study of riluzole provides the basis for predicting better benefits from disease-modifying therapies if started earlier in the course of ALS. The same premise will be explored with newer therapies that target ALS-associated genes.
Early Treatment Presumed More Effective
“We think that earlier treatment in the course of ALS is probably better for gene therapies as well,” Dr. Fournier said. She cautioned that follow-up is not yet long enough to confirm a survival benefit with tofersen, but she said it is reasonable to anticipate better and longer response when neurologic damage is limited. Citing the effect of gene therapy in spinal muscular atrophy (SMA), where progression is halted if gene therapy is initiated early in life, Dr. Fourier suggested that the emphasis on early treatment stems from the low likelihood for treatments to reverse functional impairments.
“It is conceivable that future treatments might be developed to reverse symptoms, but current drug development is largely aimed at slowing progression,” she explained. Under some circumstances, halting progression has the potential to allow some function to be regained, but as the etiologies of ALS and the pathways of progression are better understood, she believes that all targeted therapy will be started as early as possible to prevent rather than treat neurological damage.
Tofersen, the gene therapy for SOD1-ALS, has provided an opportunity to test the idea that it may be possible to prevent ALS. In a phase 3 trial called ATLAS, unaffected carriers of SOD1 variants that are associated with aggressive disease and high or complete penetrance are enrolled for a run-in phase (Part A) during which participants are followed for a rise in neurofilament light chain (NfL) levels. Based on a previous natural history study called the Pre-Symptomatic Familial ALS (Pre-fALS) study, NfL rises in the serum of unaffected SOD1 carriers prior to phenoconversion. A low NfL is an entry criterion for ATLAS.
ATLAS End Point Is Reduction in Phenoconversion to Clinically Manifest ALS
People in whom NfL rises above a predefined threshold during the run-in stage will be eligible for randomization (Part B) to receive either tofersen or placebo. Efficacy will be measured by comparing the rates of phenoconversion to clinically manifest ALS between those who receive placebo and those who receive tofersen.
Two other groups enrolled in ATLAS will be followed on open-label tofersen. One comprises people who phenoconvert during Part B and the other comprises those who develop ALS during the run-in and therefore are not enrolled in Part B. These patients, forming Parts C and D of the study, provide another set of data to evaluate whether earlier rather than later introduction of therapy provides better outcomes.
“There is a lot of interest and optimism about the trial,” said Dr. Fournier, who praised the trial design and thinks the hypothesis being explored “makes sense.”
Michael Benatar, MD, PhD, professor of neurology and public health, University of Miami School of Medicine, Miami, Florida, is the principal investigator of ATLAS and also leads the Pre-Symptomatic Familial ALS study together with a colleague, Joanne Wuu, Associate Director of Research at the University of Miami ALS Center. The hope from these initiatives, according to Dr. Fournier, is that ATLAS will offer broader learnings beyond just the SOD1 population, providing critical information about the optimal timing of treatment initiation.
The benefit from targeting genes considered causative for ALS is not yet a sure thing. A clinical trial targeting C9orf72, for example, failed to support an approvable therapy. There is a trial of a gene therapy for the FUS variant that is ongoing. Yet, the introduction of a gene therapy for SOD1 variant ALS has already established that highly targeted therapies can be effective, an important step forward after so many failed treatment trials with nonspecific drugs.
“We are seeing more and more therapies being developed to address specific ALS biology,” said Dr. Fournier, who predicts a pivot toward conceptualizing ALS as an array of pathologies rather than one disorder driven by a single mechanism. More effort is being directed to recognizing phenotypes as well as genotypes. Hopefully, more biomarkers that distinguish between ALS variants will emerge and help in individualizing treatment.
“We are not there yet, but I think many of us in the field see this as a way forward,” she said.
Multidisciplinary Care, Symptomatic Management, and Palliative Care Are Still Essential for ALS
Disease-modifying therapies are the ultimate goal in ALS, but Dr. Fournier said that the other side of the equation is multidisciplinary and palliative care. To the extent that almost all ALS therapies only modify the course of disease modestly, palliative care remains the cornerstone of day-to-day care.
“Multidisciplinary and palliative care are not necessarily novel, but they are still critically important. There are clear data to show that multidisciplinary care improves functional status and quality of life, and that this is meaningful to patients,” Dr. Fournier said.
There have been numerous improvements in the areas of multidisciplinary and palliative care, some of which can be credited to advancing technology. In centers of excellence, the multidisciplinary approach has been focused on helping patients sustain a sense of independence and self-worth.
Now robotics, devices, and software are being increasingly employed to extend patient capabilities even in relatively advanced stages of disease, according to Dr. Fournier. As one example, she cited current work in brain-computer interfaces to record electrical activity in the central nervous system to allow patients to communicate even when speech is impaired.
A focus on patient-centered clinical care is appropriate because it is the best current opportunity to improve the lives of patients with ALS. Clinically, this work is very rewarding, according to Dr. Fournier, who described ALS patients overall as generally ”very invested in advocacy and research initiatives and motivated to help others,” Dr. Fournier said.
“The diagnosis can be tough, but there is satisfaction in helping these patients navigate toward an acceptable and meaningful quality of life. They typically give a lot back,” she added.
Overall, there is a sense of progress in ALS, even though it remains a uniformly fatal disease. Dr. Fournier expressed hope that clinical research is reaching a tipping point and an emphasis on targeted treatments after a long list of failed trials over the past 30 years. However, with only one approved therapy modifying an ALS-associated gene, this approach is still in its early stages.
Dr. Fournier has financial relationships with Amylyx, Biogen, Corcept, Denali, Mitsubishi QurAlis, and Tanabe.
Suggested Reading
Benatar M et al. Design of a Randomized, Placebo-Controlled, Phase 3 Trial of Tofersen Initiated in Clinically Presymptomatic SOD1 Variant Carriers: the ATLAS Study. Neurotherapeutics. 2022 Jul;19(4):1248-1258. doi: 10.1007/s13311-022-01237-4.
Geronimo A et al. Ten Years of Riluzole Use in a Tertiary ALS Clinic. Muscle Nerve. 2022 Jun;65(6):659-666. doi: 10.1002/mus.27541.
Roggenbuck J et al. Evidence-Based Consensus Guidelines for ALS Genetic Testing and Counseling. Ann Clin Transl Neurol. 2023 Nov;10(11):2074-2091. doi: 10.1002/acn3.51895.
The first therapy targeted at modifying a mutant gene associated with amyotrophic lateral sclerosis (ALS), approved in early 2023, has offered reassurance that the biology of ALS, when known, is targetable. Historically, the disease has been considered a clinical diagnosis, but the
Despite a narrow indication, the only therapy targeted at an ALS-associated gene so far, SOD1 ALS, supports the premise that the biology of ALS can be modified, according to Christina N. Fournier, MD, an associate professor in the Department of Neurology, Emory University, Atlanta, Georgia.
Rather than a single pathological entity, ALS is best understood as the end result of many different pathological processes. Each might require its own targeted therapy in order to interrupt the upstream biological pathways that drive disease.
About 15% of ALS Has An Identifiable Genetic Cause
A family history of ALS is present in about 10% of cases. A genetic cause can be identified in approximately 15%. Cases without an identifiable genetic etiology are considered sporadic. So far, the only approved therapy that modifies the function of a gene associated with ALS is tofersen (Qalsody, Biogen), an antisense oligonucleotide. Tofersen inhibits RNA transcription of the superoxide dismutase 1 (SOD1) gene to decrease production of the SOD1 protein.
This first gene therapy for ALS is a breakthrough, but it is indicated for only a small proportion of ALS patients. Even though SOD1 gene mutations represent the second most common genetic cause of ALS after the C90rf72 gene, the proportion of patients who are candidates for tofersen is low. Efficacy is expected only in about 1% of those with familial ALS and 1% of those with sporadic ALS, or about 2% of all patients with ALS.
The evidence of benefit from a treatment with a specific target has provided the basis for concluding that “we are onto something,” Dr. Fournier said. An expert in ALS, she sees reason for excitement about the prospects in treatment with the growing focus on the underlying pathways of disease rather than the downstream consequences.
“The hope is that new gene-targeted therapies will be developed in the future to treat the broader ALS population,” said Dr. Fournier, explaining that the move toward rationally targeted treatments, whether related to gene mutations or independent molecular pathways of ALS progression, has created excitement in the field.
Numerous Disease Processes Are Potentially Targetable
As treatments are developed to address nongenetic molecular processes that contribute to the risk or progression of ALS, such as neuroinflammation or abnormal protein misfolding and aggregation, individualized treatment is likely to become key. Just as not all genetic cases share mutations in the same gene, the key molecular drivers of disease are likely to differ between patients. If so, it is hoped that biomarkers reflective of this underlying biology can be identified to appropriately target treatments.
“The excitement behind the newer targets in clinical trials is based on both basic science and early clinical data that support treatment based on specific drivers of disease,” Dr. Fournier said.
In 2023 and just prior to the FDA approval of tofersen, a set of expert consensus guidelines were published calling for genetic testing to be offered to all patients with ALS. These recommendations suggested that SOD1, C9orf72, FUS, and TARDBP should be included routinely into the panel of genes evaluated, calling for additional genes to be added as they emerge as potential therapeutic targets.
Even before these guidelines were released, genetic testing was already being offered at many centers with expertise in ALS. The rationale was to differentiate ALS with a genetic etiology from that with a nongenetic etiology, as well as to counsel family members when genetic risk was identified, but genetic testing has now assumed new urgency. In addition to the potential for offering a specific treatment for SOD1-related ALS, patients with other genetic forms of disease might be candidates for genetically focused clinical trials.
Genetic testing should be performed as soon as a diagnosis of ALS is made, according to Dr. Fournier. Although not all patients have accepted genetic testing, particularly in the past when there was no immediate clinical gain from establishing the presence of a genetic mutation, she said there is no longer any controversy about clinical relevance.
Genetic Testing Is Key to Genetic Therapies
“We do not want to miss the opportunity to treat patients when we have the chance,” said Dr. Fournier, referring to both the likely advantage of an early start of the approved gene therapy as well as the opportunity to participate in a clinical trial with other gene therapies in development.
Prior to the approval of tofersen, riluzole and edaravone had been the only disease-modifying agents in widespread use, but these drugs are nonspecific. There are no established biomarkers for establishing which patients are most likely to benefit.
In the case of riluzole, a pivotal trial conducted 30 years ago showed a survival benefit relative to placebo at 12 months (74% vs. 58%; P = 0.014). In a retrospective study published in 2022 that evaluated survival in a database of 4778 ALS patients of whom 3446 received riluzole, early diagnosis of ALS and prompt treatment with riluzole was associated with longer survival than delayed treatment. The benefit of edaravone has been validated with clinical measures, such as the revised Amyotrophic Lateral Sclerosis Functional Scale (ALSFRS-R).
The retrospective study of riluzole provides the basis for predicting better benefits from disease-modifying therapies if started earlier in the course of ALS. The same premise will be explored with newer therapies that target ALS-associated genes.
Early Treatment Presumed More Effective
“We think that earlier treatment in the course of ALS is probably better for gene therapies as well,” Dr. Fournier said. She cautioned that follow-up is not yet long enough to confirm a survival benefit with tofersen, but she said it is reasonable to anticipate better and longer response when neurologic damage is limited. Citing the effect of gene therapy in spinal muscular atrophy (SMA), where progression is halted if gene therapy is initiated early in life, Dr. Fourier suggested that the emphasis on early treatment stems from the low likelihood for treatments to reverse functional impairments.
“It is conceivable that future treatments might be developed to reverse symptoms, but current drug development is largely aimed at slowing progression,” she explained. Under some circumstances, halting progression has the potential to allow some function to be regained, but as the etiologies of ALS and the pathways of progression are better understood, she believes that all targeted therapy will be started as early as possible to prevent rather than treat neurological damage.
Tofersen, the gene therapy for SOD1-ALS, has provided an opportunity to test the idea that it may be possible to prevent ALS. In a phase 3 trial called ATLAS, unaffected carriers of SOD1 variants that are associated with aggressive disease and high or complete penetrance are enrolled for a run-in phase (Part A) during which participants are followed for a rise in neurofilament light chain (NfL) levels. Based on a previous natural history study called the Pre-Symptomatic Familial ALS (Pre-fALS) study, NfL rises in the serum of unaffected SOD1 carriers prior to phenoconversion. A low NfL is an entry criterion for ATLAS.
ATLAS End Point Is Reduction in Phenoconversion to Clinically Manifest ALS
People in whom NfL rises above a predefined threshold during the run-in stage will be eligible for randomization (Part B) to receive either tofersen or placebo. Efficacy will be measured by comparing the rates of phenoconversion to clinically manifest ALS between those who receive placebo and those who receive tofersen.
Two other groups enrolled in ATLAS will be followed on open-label tofersen. One comprises people who phenoconvert during Part B and the other comprises those who develop ALS during the run-in and therefore are not enrolled in Part B. These patients, forming Parts C and D of the study, provide another set of data to evaluate whether earlier rather than later introduction of therapy provides better outcomes.
“There is a lot of interest and optimism about the trial,” said Dr. Fournier, who praised the trial design and thinks the hypothesis being explored “makes sense.”
Michael Benatar, MD, PhD, professor of neurology and public health, University of Miami School of Medicine, Miami, Florida, is the principal investigator of ATLAS and also leads the Pre-Symptomatic Familial ALS study together with a colleague, Joanne Wuu, Associate Director of Research at the University of Miami ALS Center. The hope from these initiatives, according to Dr. Fournier, is that ATLAS will offer broader learnings beyond just the SOD1 population, providing critical information about the optimal timing of treatment initiation.
The benefit from targeting genes considered causative for ALS is not yet a sure thing. A clinical trial targeting C9orf72, for example, failed to support an approvable therapy. There is a trial of a gene therapy for the FUS variant that is ongoing. Yet, the introduction of a gene therapy for SOD1 variant ALS has already established that highly targeted therapies can be effective, an important step forward after so many failed treatment trials with nonspecific drugs.
“We are seeing more and more therapies being developed to address specific ALS biology,” said Dr. Fournier, who predicts a pivot toward conceptualizing ALS as an array of pathologies rather than one disorder driven by a single mechanism. More effort is being directed to recognizing phenotypes as well as genotypes. Hopefully, more biomarkers that distinguish between ALS variants will emerge and help in individualizing treatment.
“We are not there yet, but I think many of us in the field see this as a way forward,” she said.
Multidisciplinary Care, Symptomatic Management, and Palliative Care Are Still Essential for ALS
Disease-modifying therapies are the ultimate goal in ALS, but Dr. Fournier said that the other side of the equation is multidisciplinary and palliative care. To the extent that almost all ALS therapies only modify the course of disease modestly, palliative care remains the cornerstone of day-to-day care.
“Multidisciplinary and palliative care are not necessarily novel, but they are still critically important. There are clear data to show that multidisciplinary care improves functional status and quality of life, and that this is meaningful to patients,” Dr. Fournier said.
There have been numerous improvements in the areas of multidisciplinary and palliative care, some of which can be credited to advancing technology. In centers of excellence, the multidisciplinary approach has been focused on helping patients sustain a sense of independence and self-worth.
Now robotics, devices, and software are being increasingly employed to extend patient capabilities even in relatively advanced stages of disease, according to Dr. Fournier. As one example, she cited current work in brain-computer interfaces to record electrical activity in the central nervous system to allow patients to communicate even when speech is impaired.
A focus on patient-centered clinical care is appropriate because it is the best current opportunity to improve the lives of patients with ALS. Clinically, this work is very rewarding, according to Dr. Fournier, who described ALS patients overall as generally ”very invested in advocacy and research initiatives and motivated to help others,” Dr. Fournier said.
“The diagnosis can be tough, but there is satisfaction in helping these patients navigate toward an acceptable and meaningful quality of life. They typically give a lot back,” she added.
Overall, there is a sense of progress in ALS, even though it remains a uniformly fatal disease. Dr. Fournier expressed hope that clinical research is reaching a tipping point and an emphasis on targeted treatments after a long list of failed trials over the past 30 years. However, with only one approved therapy modifying an ALS-associated gene, this approach is still in its early stages.
Dr. Fournier has financial relationships with Amylyx, Biogen, Corcept, Denali, Mitsubishi QurAlis, and Tanabe.
Suggested Reading
Benatar M et al. Design of a Randomized, Placebo-Controlled, Phase 3 Trial of Tofersen Initiated in Clinically Presymptomatic SOD1 Variant Carriers: the ATLAS Study. Neurotherapeutics. 2022 Jul;19(4):1248-1258. doi: 10.1007/s13311-022-01237-4.
Geronimo A et al. Ten Years of Riluzole Use in a Tertiary ALS Clinic. Muscle Nerve. 2022 Jun;65(6):659-666. doi: 10.1002/mus.27541.
Roggenbuck J et al. Evidence-Based Consensus Guidelines for ALS Genetic Testing and Counseling. Ann Clin Transl Neurol. 2023 Nov;10(11):2074-2091. doi: 10.1002/acn3.51895.
The first therapy targeted at modifying a mutant gene associated with amyotrophic lateral sclerosis (ALS), approved in early 2023, has offered reassurance that the biology of ALS, when known, is targetable. Historically, the disease has been considered a clinical diagnosis, but the
Despite a narrow indication, the only therapy targeted at an ALS-associated gene so far, SOD1 ALS, supports the premise that the biology of ALS can be modified, according to Christina N. Fournier, MD, an associate professor in the Department of Neurology, Emory University, Atlanta, Georgia.
Rather than a single pathological entity, ALS is best understood as the end result of many different pathological processes. Each might require its own targeted therapy in order to interrupt the upstream biological pathways that drive disease.
About 15% of ALS Has An Identifiable Genetic Cause
A family history of ALS is present in about 10% of cases. A genetic cause can be identified in approximately 15%. Cases without an identifiable genetic etiology are considered sporadic. So far, the only approved therapy that modifies the function of a gene associated with ALS is tofersen (Qalsody, Biogen), an antisense oligonucleotide. Tofersen inhibits RNA transcription of the superoxide dismutase 1 (SOD1) gene to decrease production of the SOD1 protein.
This first gene therapy for ALS is a breakthrough, but it is indicated for only a small proportion of ALS patients. Even though SOD1 gene mutations represent the second most common genetic cause of ALS after the C90rf72 gene, the proportion of patients who are candidates for tofersen is low. Efficacy is expected only in about 1% of those with familial ALS and 1% of those with sporadic ALS, or about 2% of all patients with ALS.
The evidence of benefit from a treatment with a specific target has provided the basis for concluding that “we are onto something,” Dr. Fournier said. An expert in ALS, she sees reason for excitement about the prospects in treatment with the growing focus on the underlying pathways of disease rather than the downstream consequences.
“The hope is that new gene-targeted therapies will be developed in the future to treat the broader ALS population,” said Dr. Fournier, explaining that the move toward rationally targeted treatments, whether related to gene mutations or independent molecular pathways of ALS progression, has created excitement in the field.
Numerous Disease Processes Are Potentially Targetable
As treatments are developed to address nongenetic molecular processes that contribute to the risk or progression of ALS, such as neuroinflammation or abnormal protein misfolding and aggregation, individualized treatment is likely to become key. Just as not all genetic cases share mutations in the same gene, the key molecular drivers of disease are likely to differ between patients. If so, it is hoped that biomarkers reflective of this underlying biology can be identified to appropriately target treatments.
“The excitement behind the newer targets in clinical trials is based on both basic science and early clinical data that support treatment based on specific drivers of disease,” Dr. Fournier said.
In 2023 and just prior to the FDA approval of tofersen, a set of expert consensus guidelines were published calling for genetic testing to be offered to all patients with ALS. These recommendations suggested that SOD1, C9orf72, FUS, and TARDBP should be included routinely into the panel of genes evaluated, calling for additional genes to be added as they emerge as potential therapeutic targets.
Even before these guidelines were released, genetic testing was already being offered at many centers with expertise in ALS. The rationale was to differentiate ALS with a genetic etiology from that with a nongenetic etiology, as well as to counsel family members when genetic risk was identified, but genetic testing has now assumed new urgency. In addition to the potential for offering a specific treatment for SOD1-related ALS, patients with other genetic forms of disease might be candidates for genetically focused clinical trials.
Genetic testing should be performed as soon as a diagnosis of ALS is made, according to Dr. Fournier. Although not all patients have accepted genetic testing, particularly in the past when there was no immediate clinical gain from establishing the presence of a genetic mutation, she said there is no longer any controversy about clinical relevance.
Genetic Testing Is Key to Genetic Therapies
“We do not want to miss the opportunity to treat patients when we have the chance,” said Dr. Fournier, referring to both the likely advantage of an early start of the approved gene therapy as well as the opportunity to participate in a clinical trial with other gene therapies in development.
Prior to the approval of tofersen, riluzole and edaravone had been the only disease-modifying agents in widespread use, but these drugs are nonspecific. There are no established biomarkers for establishing which patients are most likely to benefit.
In the case of riluzole, a pivotal trial conducted 30 years ago showed a survival benefit relative to placebo at 12 months (74% vs. 58%; P = 0.014). In a retrospective study published in 2022 that evaluated survival in a database of 4778 ALS patients of whom 3446 received riluzole, early diagnosis of ALS and prompt treatment with riluzole was associated with longer survival than delayed treatment. The benefit of edaravone has been validated with clinical measures, such as the revised Amyotrophic Lateral Sclerosis Functional Scale (ALSFRS-R).
The retrospective study of riluzole provides the basis for predicting better benefits from disease-modifying therapies if started earlier in the course of ALS. The same premise will be explored with newer therapies that target ALS-associated genes.
Early Treatment Presumed More Effective
“We think that earlier treatment in the course of ALS is probably better for gene therapies as well,” Dr. Fournier said. She cautioned that follow-up is not yet long enough to confirm a survival benefit with tofersen, but she said it is reasonable to anticipate better and longer response when neurologic damage is limited. Citing the effect of gene therapy in spinal muscular atrophy (SMA), where progression is halted if gene therapy is initiated early in life, Dr. Fourier suggested that the emphasis on early treatment stems from the low likelihood for treatments to reverse functional impairments.
“It is conceivable that future treatments might be developed to reverse symptoms, but current drug development is largely aimed at slowing progression,” she explained. Under some circumstances, halting progression has the potential to allow some function to be regained, but as the etiologies of ALS and the pathways of progression are better understood, she believes that all targeted therapy will be started as early as possible to prevent rather than treat neurological damage.
Tofersen, the gene therapy for SOD1-ALS, has provided an opportunity to test the idea that it may be possible to prevent ALS. In a phase 3 trial called ATLAS, unaffected carriers of SOD1 variants that are associated with aggressive disease and high or complete penetrance are enrolled for a run-in phase (Part A) during which participants are followed for a rise in neurofilament light chain (NfL) levels. Based on a previous natural history study called the Pre-Symptomatic Familial ALS (Pre-fALS) study, NfL rises in the serum of unaffected SOD1 carriers prior to phenoconversion. A low NfL is an entry criterion for ATLAS.
ATLAS End Point Is Reduction in Phenoconversion to Clinically Manifest ALS
People in whom NfL rises above a predefined threshold during the run-in stage will be eligible for randomization (Part B) to receive either tofersen or placebo. Efficacy will be measured by comparing the rates of phenoconversion to clinically manifest ALS between those who receive placebo and those who receive tofersen.
Two other groups enrolled in ATLAS will be followed on open-label tofersen. One comprises people who phenoconvert during Part B and the other comprises those who develop ALS during the run-in and therefore are not enrolled in Part B. These patients, forming Parts C and D of the study, provide another set of data to evaluate whether earlier rather than later introduction of therapy provides better outcomes.
“There is a lot of interest and optimism about the trial,” said Dr. Fournier, who praised the trial design and thinks the hypothesis being explored “makes sense.”
Michael Benatar, MD, PhD, professor of neurology and public health, University of Miami School of Medicine, Miami, Florida, is the principal investigator of ATLAS and also leads the Pre-Symptomatic Familial ALS study together with a colleague, Joanne Wuu, Associate Director of Research at the University of Miami ALS Center. The hope from these initiatives, according to Dr. Fournier, is that ATLAS will offer broader learnings beyond just the SOD1 population, providing critical information about the optimal timing of treatment initiation.
The benefit from targeting genes considered causative for ALS is not yet a sure thing. A clinical trial targeting C9orf72, for example, failed to support an approvable therapy. There is a trial of a gene therapy for the FUS variant that is ongoing. Yet, the introduction of a gene therapy for SOD1 variant ALS has already established that highly targeted therapies can be effective, an important step forward after so many failed treatment trials with nonspecific drugs.
“We are seeing more and more therapies being developed to address specific ALS biology,” said Dr. Fournier, who predicts a pivot toward conceptualizing ALS as an array of pathologies rather than one disorder driven by a single mechanism. More effort is being directed to recognizing phenotypes as well as genotypes. Hopefully, more biomarkers that distinguish between ALS variants will emerge and help in individualizing treatment.
“We are not there yet, but I think many of us in the field see this as a way forward,” she said.
Multidisciplinary Care, Symptomatic Management, and Palliative Care Are Still Essential for ALS
Disease-modifying therapies are the ultimate goal in ALS, but Dr. Fournier said that the other side of the equation is multidisciplinary and palliative care. To the extent that almost all ALS therapies only modify the course of disease modestly, palliative care remains the cornerstone of day-to-day care.
“Multidisciplinary and palliative care are not necessarily novel, but they are still critically important. There are clear data to show that multidisciplinary care improves functional status and quality of life, and that this is meaningful to patients,” Dr. Fournier said.
There have been numerous improvements in the areas of multidisciplinary and palliative care, some of which can be credited to advancing technology. In centers of excellence, the multidisciplinary approach has been focused on helping patients sustain a sense of independence and self-worth.
Now robotics, devices, and software are being increasingly employed to extend patient capabilities even in relatively advanced stages of disease, according to Dr. Fournier. As one example, she cited current work in brain-computer interfaces to record electrical activity in the central nervous system to allow patients to communicate even when speech is impaired.
A focus on patient-centered clinical care is appropriate because it is the best current opportunity to improve the lives of patients with ALS. Clinically, this work is very rewarding, according to Dr. Fournier, who described ALS patients overall as generally ”very invested in advocacy and research initiatives and motivated to help others,” Dr. Fournier said.
“The diagnosis can be tough, but there is satisfaction in helping these patients navigate toward an acceptable and meaningful quality of life. They typically give a lot back,” she added.
Overall, there is a sense of progress in ALS, even though it remains a uniformly fatal disease. Dr. Fournier expressed hope that clinical research is reaching a tipping point and an emphasis on targeted treatments after a long list of failed trials over the past 30 years. However, with only one approved therapy modifying an ALS-associated gene, this approach is still in its early stages.
Dr. Fournier has financial relationships with Amylyx, Biogen, Corcept, Denali, Mitsubishi QurAlis, and Tanabe.
Suggested Reading
Benatar M et al. Design of a Randomized, Placebo-Controlled, Phase 3 Trial of Tofersen Initiated in Clinically Presymptomatic SOD1 Variant Carriers: the ATLAS Study. Neurotherapeutics. 2022 Jul;19(4):1248-1258. doi: 10.1007/s13311-022-01237-4.
Geronimo A et al. Ten Years of Riluzole Use in a Tertiary ALS Clinic. Muscle Nerve. 2022 Jun;65(6):659-666. doi: 10.1002/mus.27541.
Roggenbuck J et al. Evidence-Based Consensus Guidelines for ALS Genetic Testing and Counseling. Ann Clin Transl Neurol. 2023 Nov;10(11):2074-2091. doi: 10.1002/acn3.51895.
Hearing Loss, Neuropathy Cut Survival in Older Adults
TOPLINE:
METHODOLOGY:
- Researchers analyzed 793 older adults recruited from primary care practices participating in the OKLAHOMA Studies in 1999.
- Participants completed a questionnaire and underwent a physical examination; timed gait assessments (50 ft); and tests for peripheral nerve function, balance, and hearing.
- Hearing thresholds were tested at 20, 25, and 40 dB, respectively, and at sound frequencies of 500, 1000, 2000, and 4000 Hz.
- Researchers tracked mortality data over 22 years.
TAKEAWAY:
- Overall, 83% participants experienced hearing loss. Regular use of hearing aids was low, reported in 19% and 55% of those with moderate and severe hearing loss, respectively.
- Hearing loss was linked to impaired balance (P = .0014), slower walking (P = .0024), and reduced survival time (P = .0001). Moderate to severe hearing loss was strongly associated with reduced survival time (odds ratio, 1.36; P = .001), independent of the use of hearing aids.
- Peripheral neuropathy was present in 32% participants. The condition also increased the risk for death over the study period (hazard ratio [HR], 1.32; P = .003). Participants with both hearing loss and peripheral neuropathy showed reduced balance and survival time compared with people with either condition alone (HR, 1.55; P < .0001).
IN PRACTICE:
“Like peripheral neuropathy, advanced-age hearing loss is associated with reduced life expectancy, probably mediated in part through an adverse impact on balance,” the authors wrote. “Greater appreciation for the serious impacts of hearing loss and peripheral neuropathy could lead to further efforts to understand their causes and improve prevention and treatment strategies.”
SOURCE:
The study was led by James W. Mold, MD, MPH, of the University of Oklahoma Health Sciences Center, Oklahoma City. It was published online in the Journal of the American Geriatrics Society.
LIMITATIONS:
The dataset was collected in 1999 and may not entirely represent the current cohorts of older primary care patients. The absence of soundproof rooms and the exclusion of some components of the standard audiometric evaluation may have affected low-frequency sound measurements. Furthermore, physical examination was a less accurate measure of peripheral neuropathy. Information on the duration or severity of predictors and causes of death was not available.
DISCLOSURES:
The study was funded by the Presbyterian Health Foundation. The authors did not disclose any competing interests.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
TOPLINE:
METHODOLOGY:
- Researchers analyzed 793 older adults recruited from primary care practices participating in the OKLAHOMA Studies in 1999.
- Participants completed a questionnaire and underwent a physical examination; timed gait assessments (50 ft); and tests for peripheral nerve function, balance, and hearing.
- Hearing thresholds were tested at 20, 25, and 40 dB, respectively, and at sound frequencies of 500, 1000, 2000, and 4000 Hz.
- Researchers tracked mortality data over 22 years.
TAKEAWAY:
- Overall, 83% participants experienced hearing loss. Regular use of hearing aids was low, reported in 19% and 55% of those with moderate and severe hearing loss, respectively.
- Hearing loss was linked to impaired balance (P = .0014), slower walking (P = .0024), and reduced survival time (P = .0001). Moderate to severe hearing loss was strongly associated with reduced survival time (odds ratio, 1.36; P = .001), independent of the use of hearing aids.
- Peripheral neuropathy was present in 32% participants. The condition also increased the risk for death over the study period (hazard ratio [HR], 1.32; P = .003). Participants with both hearing loss and peripheral neuropathy showed reduced balance and survival time compared with people with either condition alone (HR, 1.55; P < .0001).
IN PRACTICE:
“Like peripheral neuropathy, advanced-age hearing loss is associated with reduced life expectancy, probably mediated in part through an adverse impact on balance,” the authors wrote. “Greater appreciation for the serious impacts of hearing loss and peripheral neuropathy could lead to further efforts to understand their causes and improve prevention and treatment strategies.”
SOURCE:
The study was led by James W. Mold, MD, MPH, of the University of Oklahoma Health Sciences Center, Oklahoma City. It was published online in the Journal of the American Geriatrics Society.
LIMITATIONS:
The dataset was collected in 1999 and may not entirely represent the current cohorts of older primary care patients. The absence of soundproof rooms and the exclusion of some components of the standard audiometric evaluation may have affected low-frequency sound measurements. Furthermore, physical examination was a less accurate measure of peripheral neuropathy. Information on the duration or severity of predictors and causes of death was not available.
DISCLOSURES:
The study was funded by the Presbyterian Health Foundation. The authors did not disclose any competing interests.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
TOPLINE:
METHODOLOGY:
- Researchers analyzed 793 older adults recruited from primary care practices participating in the OKLAHOMA Studies in 1999.
- Participants completed a questionnaire and underwent a physical examination; timed gait assessments (50 ft); and tests for peripheral nerve function, balance, and hearing.
- Hearing thresholds were tested at 20, 25, and 40 dB, respectively, and at sound frequencies of 500, 1000, 2000, and 4000 Hz.
- Researchers tracked mortality data over 22 years.
TAKEAWAY:
- Overall, 83% participants experienced hearing loss. Regular use of hearing aids was low, reported in 19% and 55% of those with moderate and severe hearing loss, respectively.
- Hearing loss was linked to impaired balance (P = .0014), slower walking (P = .0024), and reduced survival time (P = .0001). Moderate to severe hearing loss was strongly associated with reduced survival time (odds ratio, 1.36; P = .001), independent of the use of hearing aids.
- Peripheral neuropathy was present in 32% participants. The condition also increased the risk for death over the study period (hazard ratio [HR], 1.32; P = .003). Participants with both hearing loss and peripheral neuropathy showed reduced balance and survival time compared with people with either condition alone (HR, 1.55; P < .0001).
IN PRACTICE:
“Like peripheral neuropathy, advanced-age hearing loss is associated with reduced life expectancy, probably mediated in part through an adverse impact on balance,” the authors wrote. “Greater appreciation for the serious impacts of hearing loss and peripheral neuropathy could lead to further efforts to understand their causes and improve prevention and treatment strategies.”
SOURCE:
The study was led by James W. Mold, MD, MPH, of the University of Oklahoma Health Sciences Center, Oklahoma City. It was published online in the Journal of the American Geriatrics Society.
LIMITATIONS:
The dataset was collected in 1999 and may not entirely represent the current cohorts of older primary care patients. The absence of soundproof rooms and the exclusion of some components of the standard audiometric evaluation may have affected low-frequency sound measurements. Furthermore, physical examination was a less accurate measure of peripheral neuropathy. Information on the duration or severity of predictors and causes of death was not available.
DISCLOSURES:
The study was funded by the Presbyterian Health Foundation. The authors did not disclose any competing interests.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article appeared on Medscape.com.
Mobile App Shows Promise in Managing Fibromyalgia Symptoms
TOPLINE:
A smartphone app that delivers acceptance and commitment therapy (ACT), a type of cognitive behavioral therapy, improves overall well-being and reduces the severity of pain, fatigue, sleep issues, and depression to a greater extent than daily symptom tracking in patients with fibromyalgia.
METHODOLOGY:
- Researchers conducted the phase 3 PROSPER-FM trial at 25 community sites in the United States to assess the efficacy and safety of digital ACT for patients with fibromyalgia.
- A total of 275 adult patients aged 22-75 years with fibromyalgia were randomly assigned to either the digital ACT group (n = 140) or the active control group (n = 135) for 12 weeks.
- Patients in the digital ACT group received a self-guided, smartphone-delivered program in which they learned and practiced the core ACT skills of acceptance, values, mindfulness, defusion, self as context, and willingness and committed action to build psychological flexibility, while the control group underwent daily symptom tracking and received educational materials.
- The primary endpoint was the response rate on the Patient Global Impression of Change (PGIC) at week 12, which is an indicator of patient well-being.
- The secondary endpoints included changes in the Revised Fibromyalgia Impact Questionnaire (FIQ-R) total score and pain intensity, pain interference, and sleep interference scores.
TAKEAWAY:
- At week 12, 71% of the patients in the digital ACT group responded with a minimally improved or better change in the PGIC response, compared with only 22% of the patients in the control group (P < .0001).
- The digital ACT group showed a significant reduction in the impact of fibromyalgia, with a between-group effect size of d = 0.65 (P < .0001) at week 12. The FIQ-R total score significantly improved within 3 weeks of using the self-guided digital ACT app.
- The use of digital ACT also demonstrated positive effects on the levels of weekly pain intensity (P = .001) and depression (P < .0001), compared with the control group.
- No serious adverse effects related to the app were reported, and both groups demonstrated high rates of adherence, with most (72%) participants in the digital ACT group completing at least 42 sessions.
IN PRACTICE:
“The results found in the study are essential for professionals who care for patients with fibromyalgia as they present a new viable treatment alternative,” Guilherme Torres Vilarino, PhD, Santa Catarina State University, Florianópolis, Brazil, wrote in an accompanying editorial.
SOURCE:
This study was led by R. Michael Gendreau, MD, PhD, Gendreau Consulting, Poway, California. It was published online in The Lancet.
LIMITATIONS:
The study population predominantly consisted of women and White individuals, which may limit the generalizability of the findings to more diverse populations. Additionally, the study was conducted in the United States, and the results may thus not be applicable to other countries with different racial, ethnic, educational, and economic characteristics. The study duration was 12 weeks, and the long-term benefits of digital ACT have not yet been shown.
DISCLOSURES:
This study was funded by Swing Therapeutics. Seven authors declared having stock options and/or receiving salary from Swing Therapeutics. Other authors reported having many ties with several sources, including Swing Therapeutics.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
A smartphone app that delivers acceptance and commitment therapy (ACT), a type of cognitive behavioral therapy, improves overall well-being and reduces the severity of pain, fatigue, sleep issues, and depression to a greater extent than daily symptom tracking in patients with fibromyalgia.
METHODOLOGY:
- Researchers conducted the phase 3 PROSPER-FM trial at 25 community sites in the United States to assess the efficacy and safety of digital ACT for patients with fibromyalgia.
- A total of 275 adult patients aged 22-75 years with fibromyalgia were randomly assigned to either the digital ACT group (n = 140) or the active control group (n = 135) for 12 weeks.
- Patients in the digital ACT group received a self-guided, smartphone-delivered program in which they learned and practiced the core ACT skills of acceptance, values, mindfulness, defusion, self as context, and willingness and committed action to build psychological flexibility, while the control group underwent daily symptom tracking and received educational materials.
- The primary endpoint was the response rate on the Patient Global Impression of Change (PGIC) at week 12, which is an indicator of patient well-being.
- The secondary endpoints included changes in the Revised Fibromyalgia Impact Questionnaire (FIQ-R) total score and pain intensity, pain interference, and sleep interference scores.
TAKEAWAY:
- At week 12, 71% of the patients in the digital ACT group responded with a minimally improved or better change in the PGIC response, compared with only 22% of the patients in the control group (P < .0001).
- The digital ACT group showed a significant reduction in the impact of fibromyalgia, with a between-group effect size of d = 0.65 (P < .0001) at week 12. The FIQ-R total score significantly improved within 3 weeks of using the self-guided digital ACT app.
- The use of digital ACT also demonstrated positive effects on the levels of weekly pain intensity (P = .001) and depression (P < .0001), compared with the control group.
- No serious adverse effects related to the app were reported, and both groups demonstrated high rates of adherence, with most (72%) participants in the digital ACT group completing at least 42 sessions.
IN PRACTICE:
“The results found in the study are essential for professionals who care for patients with fibromyalgia as they present a new viable treatment alternative,” Guilherme Torres Vilarino, PhD, Santa Catarina State University, Florianópolis, Brazil, wrote in an accompanying editorial.
SOURCE:
This study was led by R. Michael Gendreau, MD, PhD, Gendreau Consulting, Poway, California. It was published online in The Lancet.
LIMITATIONS:
The study population predominantly consisted of women and White individuals, which may limit the generalizability of the findings to more diverse populations. Additionally, the study was conducted in the United States, and the results may thus not be applicable to other countries with different racial, ethnic, educational, and economic characteristics. The study duration was 12 weeks, and the long-term benefits of digital ACT have not yet been shown.
DISCLOSURES:
This study was funded by Swing Therapeutics. Seven authors declared having stock options and/or receiving salary from Swing Therapeutics. Other authors reported having many ties with several sources, including Swing Therapeutics.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
TOPLINE:
A smartphone app that delivers acceptance and commitment therapy (ACT), a type of cognitive behavioral therapy, improves overall well-being and reduces the severity of pain, fatigue, sleep issues, and depression to a greater extent than daily symptom tracking in patients with fibromyalgia.
METHODOLOGY:
- Researchers conducted the phase 3 PROSPER-FM trial at 25 community sites in the United States to assess the efficacy and safety of digital ACT for patients with fibromyalgia.
- A total of 275 adult patients aged 22-75 years with fibromyalgia were randomly assigned to either the digital ACT group (n = 140) or the active control group (n = 135) for 12 weeks.
- Patients in the digital ACT group received a self-guided, smartphone-delivered program in which they learned and practiced the core ACT skills of acceptance, values, mindfulness, defusion, self as context, and willingness and committed action to build psychological flexibility, while the control group underwent daily symptom tracking and received educational materials.
- The primary endpoint was the response rate on the Patient Global Impression of Change (PGIC) at week 12, which is an indicator of patient well-being.
- The secondary endpoints included changes in the Revised Fibromyalgia Impact Questionnaire (FIQ-R) total score and pain intensity, pain interference, and sleep interference scores.
TAKEAWAY:
- At week 12, 71% of the patients in the digital ACT group responded with a minimally improved or better change in the PGIC response, compared with only 22% of the patients in the control group (P < .0001).
- The digital ACT group showed a significant reduction in the impact of fibromyalgia, with a between-group effect size of d = 0.65 (P < .0001) at week 12. The FIQ-R total score significantly improved within 3 weeks of using the self-guided digital ACT app.
- The use of digital ACT also demonstrated positive effects on the levels of weekly pain intensity (P = .001) and depression (P < .0001), compared with the control group.
- No serious adverse effects related to the app were reported, and both groups demonstrated high rates of adherence, with most (72%) participants in the digital ACT group completing at least 42 sessions.
IN PRACTICE:
“The results found in the study are essential for professionals who care for patients with fibromyalgia as they present a new viable treatment alternative,” Guilherme Torres Vilarino, PhD, Santa Catarina State University, Florianópolis, Brazil, wrote in an accompanying editorial.
SOURCE:
This study was led by R. Michael Gendreau, MD, PhD, Gendreau Consulting, Poway, California. It was published online in The Lancet.
LIMITATIONS:
The study population predominantly consisted of women and White individuals, which may limit the generalizability of the findings to more diverse populations. Additionally, the study was conducted in the United States, and the results may thus not be applicable to other countries with different racial, ethnic, educational, and economic characteristics. The study duration was 12 weeks, and the long-term benefits of digital ACT have not yet been shown.
DISCLOSURES:
This study was funded by Swing Therapeutics. Seven authors declared having stock options and/or receiving salary from Swing Therapeutics. Other authors reported having many ties with several sources, including Swing Therapeutics.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.
‘Doesn’t Fit Anything I Trained for’: Committee Examines Treatment for Chronic Illness After Lyme Disease
WASHINGTON — Advancing treatment for what has been variably called chronic Lyme and posttreatment Lyme disease (PTLD) is under the eyes of a National Academies of Science, Engineering, and Medicine (NASEM) committee of experts for the first time — a year after the NASEM shone a spotlight on the need to accelerate research on chronic illnesses that follow known or suspected infections.
The committee will not make recommendations on specific approaches to diagnosis and treatment when it issues a report in early 2025 but will instead present “consensus findings” on treatment for chronic illness associated with Lyme disease, including recommendations for advancing treatment.
It’s an area void of the US Food and Drug Administration–approved therapies, void of any consensus on the off-label use of medications, and without any current standard of care or proven mechanisms and pathophysiology, said John Aucott, MD, director of the Johns Hopkins Medicine Lyme Disease Clinical Research Center, Baltimore, one of the invited speakers at a public meeting held by the NASEM in Washington, DC.
“The best way to look at this illness is not from the silos of infectious disease or the silos of rheumatology; you have to look across disciplines,” Dr. Aucott, also associate professor of medicine in the Division of Rheumatology, told the committee. “The story doesn’t fit anything I trained for in my infectious disease fellowship. Even today, I’d posit that PTLD is like an island — it’s still not connected to a lot of the mainstream of medicine.”
Rhisa Parera, who wrote and directed a 2021 documentary, Your Labs Are Normal, was one of several invited speakers who amplified the patient voice. Starting around age 7, she had pain in her knees, spine, and hips and vivid nightmares. In high school, she developed gastrointestinal issues, and in college, she developed debilitating neurologic symptoms.
Depression was her eventual diagnosis after having seen “every specialist in the book,” she said. At age 29, she received a positive western blot test and a Lyme disease diagnosis, at which point “I was prescribed 4 weeks of doxycycline and left in the dark,” the 34-year-old Black patient told the committee. Her health improved only after she began working with an “LLMD,” or Lyme-literate medical doctor (a term used in the patient community), while she lived with her mother and did not work, she said.
“I don’t share my Lyme disease history with other doctors. It’s pointless when you have those who will laugh at you, say you’re fine if you were treated, or just deny the disease completely,” Ms. Parera said. “We need this to be taught in medical school. It’s a literal emergency.”
Incidence and Potential Mechanisms
Limited research has suggested that 10%-20% of patients with Lyme disease develop persistent symptoms after standard antibiotic treatment advised by the Infectious Diseases Society of America (IDSA), Dr. Aucott said. (On its web page on chronic symptoms, the Centers for Disease Control and Prevention presents a more conservative range of 5%-10%.)
His own prospective cohort study at Johns Hopkins, published in 2022, found that 13.7% of 234 patients with prior Lyme disease met symptom and functional impact criteria for PTLD, compared with 4.1% of 49 participants without a history of Lyme disease — a statistically significant difference that he said should “put to rest” the question of “is it real?”
PTLD is the research case definition proposed by the IDSA in 2006; it requires that patients have prior documented Lyme disease, no other specific comorbidities, and specific symptoms (fatigue, widespread musculoskeletal pain, and/or cognitive difficulties) causing significant functional impact at least 6 months from their initial diagnosis and treatment.
In the real world, however, where diagnostics for acute Lyme disease are often inaccurate, erythema migrans is often absent, and the symptomatology of Lyme IACI is variable (and where there is no approved laboratory test or objective biomarker for diagnosing Lyme IACI), PTLD represents only a subset of a broader, heterogeneous population with persistent symptoms.
The term “Lyme IACI,” pronounced “Lyme eye-ACK-ee” at the meeting, builds on conversations at the 2023 NASEM workshop on infection-associated chronic illnesses and “encompasses a variety of terms that are used,” including PTLD, PTLD syndrome, persistent Lyme disease, and chronic Lyme disease, according to committee documents. Symptoms are distinct from the known complications of Lyme disease, such as arthritis or carditis.
The findings from Dr. Aucott’s SLICE cohort likely represent “the best outcome,” he said. They’re “probably not generalizable to a community setting where we see lots of missed diagnoses and delayed diagnoses,” as well as other tick-borne coinfections.
One of the challenges in designing future trials, in fact, relates to enrollment criteria and whether to use strict inclusion and exclusion criteria associated with the IDSA definition or take a broader approach to trial enrollment, he and others said. “You want to enroll patients for whom there’s no controversy that they’ve had Lyme infection ... for a study people believe in,” Dr. Aucott said during a discussion period, noting that it’s typical to screen over 100 patients to find one enrollee. “But it’s a tension we’re having.”
Timothy Sellati, PhD, chief scientific officer of the Global Lyme Alliance, urged change. “It’s really important to try to figure out how to alter our thinking on identifying and diagnosing chronic Lyme patients because they need to be recruited into clinical trials,” he said during his presentation.
“We think the best way to do this is to [develop and] employ composite diagnostic testing” that looks at unique Borrelia signatures (eg, protein, DNA, RNA, or metabolites), genetic and/or epigenetic signatures, inflammation signatures, T-cell-independent antibody signatures, and other elements, Dr. Sellati said.
Researchers designing treatment trials also face unknowns, Dr. Aucott and others said, about the role of potential mechanisms of Lyme IACI, from persistent Borrelia burgdorferi (or Borrelia mayonii) infection or the persistence of bacterial remnants (eg, nucleic acids or peptidoglycans) to infection-triggered pathology such as persistent immune dysregulation, chronic inflammation, autoimmunity, microbiome alterations, and dysautonomia and other neural network alterations.
The NASEM’s spotlight on Lyme IACI follows its long COVID-driven push last year to advance a common research agenda in infection-associated chronic illnesses. Investigators see common symptoms and potential shared mechanisms between long COVID, Lyme IACI, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic illnesses following infections.
At the Lyme IACI meeting, invited speakers described parts of the research landscape. Avindra Nath, MD, of the National Institute of Neurological Disorders and Stroke, for instance, described a recently published deep phenotyping study of 17 patients with ME/CFS that found decreased central catecholamine synthesis, circuit dysfunction of integrative brain regions, and immune profiling differences (eg, defects in B-cell maturation or T-cell exhaustion), compared with matched controls, that suggest the persistence of microbial antigens.
And John Leong, MD, PhD, of Tufts University, Boston, described his lab’s focus on understanding the microbe-host interactions that enable bloodstream dissemination and tissue invasion of B burgdorferi to take hold, increasing the risk for persistent symptoms. Other research at Tufts, he noted during a discussion period, has demonstrated the persistence of B burgdorferi to antibiotics in microtiter dishes. “Those organisms that survive are really difficult to eradicate in vitro,” Dr. Leong said.
Other physician investigators described research on nociplastic pain — a category of pain that can be triggered by infections, causing both amplified sensory processing and augmented central nervous system pain — and on whether reactivation of the Epstein-Barr virus could potentiate autoimmunity in the context of Borrelia infection.
Researchers are ready to test therapies while pathophysiology is unraveled — provided there is funding, Dr. Aucott said. The Clinical Trials Network for Lyme and Other Tick-Borne Diseases, coordinated by Brian Fallon, MD, of Columbia University, New York City, and funded several years ago by the Steven & Alexandra Cohen Foundation, has a slate of small pilot studies underway or being planned that address potential mechanisms (eg, studies of pulse intravenous ceftriaxone, tetracycline, transauricular vagus nerve stimulation, and mast cell modulation). And should full multisite trials be designed and funded, the network is ready with an infrastructure.
Need for Patient-Centered Outcomes
Persistent symptomatology is on the NIH’s radar screen. Efforts to understand causes were part of a strategic tick-borne disease research plan developed by the NIH in 2019. And in 2023, the National Institute of Allergy and Infectious Diseases (NIAID) funded seven projects addressing persistent symptoms that will run through 2028, C. Benjamin Beard, PhD, deputy division director of the CDC’s Division of Vector-Borne Disease, said at the NASEM committee meeting.
Patient advocates maintained that too much emphasis is placed on tick biology and pathophysiology. When Wendy Adams, research grant director and advisory board member of the Bay Area Lyme Foundation, and a colleague analyzed NIAID tick-borne disease funding from 2013 to 2021, they found that 75% of the funding went toward basic research, 15% to translational research, and “only 3% went to clinical research,” Ms. Adams told the committee.
Only 3% of the basic research budget was spent on coinfections, she said, and only 1% was spent on neurologic disease associated with tick-borne infections, both of which are survey-defined patient priorities. Moreover, “12% of the overall NIAID [tick-borne diseases] budget was spent on tick biology,” she said.
Research needs to involve community physicians who are utilizing the guidelines and approaches of the International Lyme and Associated Diseases Society to treat most patients with Lyme IACI, Ms. Adams said. “They have data to be mined,” she said, as does LymeDisease.org, which maintains a patient registry, MyLymeData, with over 18,000 patients. The organization has published two treatment studies, including one on antibiotic treatment response.
Lorraine Johnson, JD, MBA, CEO of LymeDisease.org and principal investigator of MyLymeData, stressed the importance of using patient-centered outcomes that incorporate minimal clinically important differences (MCIDs). “A change in the SF-36 score [without consideration of MCIDs] is not inherently important or meaningful to patients,” she said, referring to the SF-36 survey of health-related quality of life.
“This may seem like an esoteric issue, but two of the four clinical trials done [on retreatment of] persistent Lyme disease used the SF-36 as their outcome measure, and those studies, led by [Mark] Klempner, concluded that retreatment was not effective,” Ms. Johnson said. “Patients have been and continue to be harmed by [this research] because they’re told by physicians that antibiotics don’t work.”
A 2012 biostatistical review of these four RCTs — trials that helped inform the 2006 IDSA treatment guidelines — concluded that the Klempner studies “set the bar for treatment success too high,” Ms. Johnson said. Three of the four trials were likely underpowered to detect clinically meaningful treatment effects, the review also found.
The NASEM committee will hold additional public meetings and review a wide range of literature through this year. The formation of the committee was recommended by the US Department of Health and Human Services Tick-Borne Disease Working Group that was established by Congress in 2016 and concluded its work in 2022. The committee’s work is funded by the Cohen Foundation.
A version of this article appeared on Medscape.com.
WASHINGTON — Advancing treatment for what has been variably called chronic Lyme and posttreatment Lyme disease (PTLD) is under the eyes of a National Academies of Science, Engineering, and Medicine (NASEM) committee of experts for the first time — a year after the NASEM shone a spotlight on the need to accelerate research on chronic illnesses that follow known or suspected infections.
The committee will not make recommendations on specific approaches to diagnosis and treatment when it issues a report in early 2025 but will instead present “consensus findings” on treatment for chronic illness associated with Lyme disease, including recommendations for advancing treatment.
It’s an area void of the US Food and Drug Administration–approved therapies, void of any consensus on the off-label use of medications, and without any current standard of care or proven mechanisms and pathophysiology, said John Aucott, MD, director of the Johns Hopkins Medicine Lyme Disease Clinical Research Center, Baltimore, one of the invited speakers at a public meeting held by the NASEM in Washington, DC.
“The best way to look at this illness is not from the silos of infectious disease or the silos of rheumatology; you have to look across disciplines,” Dr. Aucott, also associate professor of medicine in the Division of Rheumatology, told the committee. “The story doesn’t fit anything I trained for in my infectious disease fellowship. Even today, I’d posit that PTLD is like an island — it’s still not connected to a lot of the mainstream of medicine.”
Rhisa Parera, who wrote and directed a 2021 documentary, Your Labs Are Normal, was one of several invited speakers who amplified the patient voice. Starting around age 7, she had pain in her knees, spine, and hips and vivid nightmares. In high school, she developed gastrointestinal issues, and in college, she developed debilitating neurologic symptoms.
Depression was her eventual diagnosis after having seen “every specialist in the book,” she said. At age 29, she received a positive western blot test and a Lyme disease diagnosis, at which point “I was prescribed 4 weeks of doxycycline and left in the dark,” the 34-year-old Black patient told the committee. Her health improved only after she began working with an “LLMD,” or Lyme-literate medical doctor (a term used in the patient community), while she lived with her mother and did not work, she said.
“I don’t share my Lyme disease history with other doctors. It’s pointless when you have those who will laugh at you, say you’re fine if you were treated, or just deny the disease completely,” Ms. Parera said. “We need this to be taught in medical school. It’s a literal emergency.”
Incidence and Potential Mechanisms
Limited research has suggested that 10%-20% of patients with Lyme disease develop persistent symptoms after standard antibiotic treatment advised by the Infectious Diseases Society of America (IDSA), Dr. Aucott said. (On its web page on chronic symptoms, the Centers for Disease Control and Prevention presents a more conservative range of 5%-10%.)
His own prospective cohort study at Johns Hopkins, published in 2022, found that 13.7% of 234 patients with prior Lyme disease met symptom and functional impact criteria for PTLD, compared with 4.1% of 49 participants without a history of Lyme disease — a statistically significant difference that he said should “put to rest” the question of “is it real?”
PTLD is the research case definition proposed by the IDSA in 2006; it requires that patients have prior documented Lyme disease, no other specific comorbidities, and specific symptoms (fatigue, widespread musculoskeletal pain, and/or cognitive difficulties) causing significant functional impact at least 6 months from their initial diagnosis and treatment.
In the real world, however, where diagnostics for acute Lyme disease are often inaccurate, erythema migrans is often absent, and the symptomatology of Lyme IACI is variable (and where there is no approved laboratory test or objective biomarker for diagnosing Lyme IACI), PTLD represents only a subset of a broader, heterogeneous population with persistent symptoms.
The term “Lyme IACI,” pronounced “Lyme eye-ACK-ee” at the meeting, builds on conversations at the 2023 NASEM workshop on infection-associated chronic illnesses and “encompasses a variety of terms that are used,” including PTLD, PTLD syndrome, persistent Lyme disease, and chronic Lyme disease, according to committee documents. Symptoms are distinct from the known complications of Lyme disease, such as arthritis or carditis.
The findings from Dr. Aucott’s SLICE cohort likely represent “the best outcome,” he said. They’re “probably not generalizable to a community setting where we see lots of missed diagnoses and delayed diagnoses,” as well as other tick-borne coinfections.
One of the challenges in designing future trials, in fact, relates to enrollment criteria and whether to use strict inclusion and exclusion criteria associated with the IDSA definition or take a broader approach to trial enrollment, he and others said. “You want to enroll patients for whom there’s no controversy that they’ve had Lyme infection ... for a study people believe in,” Dr. Aucott said during a discussion period, noting that it’s typical to screen over 100 patients to find one enrollee. “But it’s a tension we’re having.”
Timothy Sellati, PhD, chief scientific officer of the Global Lyme Alliance, urged change. “It’s really important to try to figure out how to alter our thinking on identifying and diagnosing chronic Lyme patients because they need to be recruited into clinical trials,” he said during his presentation.
“We think the best way to do this is to [develop and] employ composite diagnostic testing” that looks at unique Borrelia signatures (eg, protein, DNA, RNA, or metabolites), genetic and/or epigenetic signatures, inflammation signatures, T-cell-independent antibody signatures, and other elements, Dr. Sellati said.
Researchers designing treatment trials also face unknowns, Dr. Aucott and others said, about the role of potential mechanisms of Lyme IACI, from persistent Borrelia burgdorferi (or Borrelia mayonii) infection or the persistence of bacterial remnants (eg, nucleic acids or peptidoglycans) to infection-triggered pathology such as persistent immune dysregulation, chronic inflammation, autoimmunity, microbiome alterations, and dysautonomia and other neural network alterations.
The NASEM’s spotlight on Lyme IACI follows its long COVID-driven push last year to advance a common research agenda in infection-associated chronic illnesses. Investigators see common symptoms and potential shared mechanisms between long COVID, Lyme IACI, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic illnesses following infections.
At the Lyme IACI meeting, invited speakers described parts of the research landscape. Avindra Nath, MD, of the National Institute of Neurological Disorders and Stroke, for instance, described a recently published deep phenotyping study of 17 patients with ME/CFS that found decreased central catecholamine synthesis, circuit dysfunction of integrative brain regions, and immune profiling differences (eg, defects in B-cell maturation or T-cell exhaustion), compared with matched controls, that suggest the persistence of microbial antigens.
And John Leong, MD, PhD, of Tufts University, Boston, described his lab’s focus on understanding the microbe-host interactions that enable bloodstream dissemination and tissue invasion of B burgdorferi to take hold, increasing the risk for persistent symptoms. Other research at Tufts, he noted during a discussion period, has demonstrated the persistence of B burgdorferi to antibiotics in microtiter dishes. “Those organisms that survive are really difficult to eradicate in vitro,” Dr. Leong said.
Other physician investigators described research on nociplastic pain — a category of pain that can be triggered by infections, causing both amplified sensory processing and augmented central nervous system pain — and on whether reactivation of the Epstein-Barr virus could potentiate autoimmunity in the context of Borrelia infection.
Researchers are ready to test therapies while pathophysiology is unraveled — provided there is funding, Dr. Aucott said. The Clinical Trials Network for Lyme and Other Tick-Borne Diseases, coordinated by Brian Fallon, MD, of Columbia University, New York City, and funded several years ago by the Steven & Alexandra Cohen Foundation, has a slate of small pilot studies underway or being planned that address potential mechanisms (eg, studies of pulse intravenous ceftriaxone, tetracycline, transauricular vagus nerve stimulation, and mast cell modulation). And should full multisite trials be designed and funded, the network is ready with an infrastructure.
Need for Patient-Centered Outcomes
Persistent symptomatology is on the NIH’s radar screen. Efforts to understand causes were part of a strategic tick-borne disease research plan developed by the NIH in 2019. And in 2023, the National Institute of Allergy and Infectious Diseases (NIAID) funded seven projects addressing persistent symptoms that will run through 2028, C. Benjamin Beard, PhD, deputy division director of the CDC’s Division of Vector-Borne Disease, said at the NASEM committee meeting.
Patient advocates maintained that too much emphasis is placed on tick biology and pathophysiology. When Wendy Adams, research grant director and advisory board member of the Bay Area Lyme Foundation, and a colleague analyzed NIAID tick-borne disease funding from 2013 to 2021, they found that 75% of the funding went toward basic research, 15% to translational research, and “only 3% went to clinical research,” Ms. Adams told the committee.
Only 3% of the basic research budget was spent on coinfections, she said, and only 1% was spent on neurologic disease associated with tick-borne infections, both of which are survey-defined patient priorities. Moreover, “12% of the overall NIAID [tick-borne diseases] budget was spent on tick biology,” she said.
Research needs to involve community physicians who are utilizing the guidelines and approaches of the International Lyme and Associated Diseases Society to treat most patients with Lyme IACI, Ms. Adams said. “They have data to be mined,” she said, as does LymeDisease.org, which maintains a patient registry, MyLymeData, with over 18,000 patients. The organization has published two treatment studies, including one on antibiotic treatment response.
Lorraine Johnson, JD, MBA, CEO of LymeDisease.org and principal investigator of MyLymeData, stressed the importance of using patient-centered outcomes that incorporate minimal clinically important differences (MCIDs). “A change in the SF-36 score [without consideration of MCIDs] is not inherently important or meaningful to patients,” she said, referring to the SF-36 survey of health-related quality of life.
“This may seem like an esoteric issue, but two of the four clinical trials done [on retreatment of] persistent Lyme disease used the SF-36 as their outcome measure, and those studies, led by [Mark] Klempner, concluded that retreatment was not effective,” Ms. Johnson said. “Patients have been and continue to be harmed by [this research] because they’re told by physicians that antibiotics don’t work.”
A 2012 biostatistical review of these four RCTs — trials that helped inform the 2006 IDSA treatment guidelines — concluded that the Klempner studies “set the bar for treatment success too high,” Ms. Johnson said. Three of the four trials were likely underpowered to detect clinically meaningful treatment effects, the review also found.
The NASEM committee will hold additional public meetings and review a wide range of literature through this year. The formation of the committee was recommended by the US Department of Health and Human Services Tick-Borne Disease Working Group that was established by Congress in 2016 and concluded its work in 2022. The committee’s work is funded by the Cohen Foundation.
A version of this article appeared on Medscape.com.
WASHINGTON — Advancing treatment for what has been variably called chronic Lyme and posttreatment Lyme disease (PTLD) is under the eyes of a National Academies of Science, Engineering, and Medicine (NASEM) committee of experts for the first time — a year after the NASEM shone a spotlight on the need to accelerate research on chronic illnesses that follow known or suspected infections.
The committee will not make recommendations on specific approaches to diagnosis and treatment when it issues a report in early 2025 but will instead present “consensus findings” on treatment for chronic illness associated with Lyme disease, including recommendations for advancing treatment.
It’s an area void of the US Food and Drug Administration–approved therapies, void of any consensus on the off-label use of medications, and without any current standard of care or proven mechanisms and pathophysiology, said John Aucott, MD, director of the Johns Hopkins Medicine Lyme Disease Clinical Research Center, Baltimore, one of the invited speakers at a public meeting held by the NASEM in Washington, DC.
“The best way to look at this illness is not from the silos of infectious disease or the silos of rheumatology; you have to look across disciplines,” Dr. Aucott, also associate professor of medicine in the Division of Rheumatology, told the committee. “The story doesn’t fit anything I trained for in my infectious disease fellowship. Even today, I’d posit that PTLD is like an island — it’s still not connected to a lot of the mainstream of medicine.”
Rhisa Parera, who wrote and directed a 2021 documentary, Your Labs Are Normal, was one of several invited speakers who amplified the patient voice. Starting around age 7, she had pain in her knees, spine, and hips and vivid nightmares. In high school, she developed gastrointestinal issues, and in college, she developed debilitating neurologic symptoms.
Depression was her eventual diagnosis after having seen “every specialist in the book,” she said. At age 29, she received a positive western blot test and a Lyme disease diagnosis, at which point “I was prescribed 4 weeks of doxycycline and left in the dark,” the 34-year-old Black patient told the committee. Her health improved only after she began working with an “LLMD,” or Lyme-literate medical doctor (a term used in the patient community), while she lived with her mother and did not work, she said.
“I don’t share my Lyme disease history with other doctors. It’s pointless when you have those who will laugh at you, say you’re fine if you were treated, or just deny the disease completely,” Ms. Parera said. “We need this to be taught in medical school. It’s a literal emergency.”
Incidence and Potential Mechanisms
Limited research has suggested that 10%-20% of patients with Lyme disease develop persistent symptoms after standard antibiotic treatment advised by the Infectious Diseases Society of America (IDSA), Dr. Aucott said. (On its web page on chronic symptoms, the Centers for Disease Control and Prevention presents a more conservative range of 5%-10%.)
His own prospective cohort study at Johns Hopkins, published in 2022, found that 13.7% of 234 patients with prior Lyme disease met symptom and functional impact criteria for PTLD, compared with 4.1% of 49 participants without a history of Lyme disease — a statistically significant difference that he said should “put to rest” the question of “is it real?”
PTLD is the research case definition proposed by the IDSA in 2006; it requires that patients have prior documented Lyme disease, no other specific comorbidities, and specific symptoms (fatigue, widespread musculoskeletal pain, and/or cognitive difficulties) causing significant functional impact at least 6 months from their initial diagnosis and treatment.
In the real world, however, where diagnostics for acute Lyme disease are often inaccurate, erythema migrans is often absent, and the symptomatology of Lyme IACI is variable (and where there is no approved laboratory test or objective biomarker for diagnosing Lyme IACI), PTLD represents only a subset of a broader, heterogeneous population with persistent symptoms.
The term “Lyme IACI,” pronounced “Lyme eye-ACK-ee” at the meeting, builds on conversations at the 2023 NASEM workshop on infection-associated chronic illnesses and “encompasses a variety of terms that are used,” including PTLD, PTLD syndrome, persistent Lyme disease, and chronic Lyme disease, according to committee documents. Symptoms are distinct from the known complications of Lyme disease, such as arthritis or carditis.
The findings from Dr. Aucott’s SLICE cohort likely represent “the best outcome,” he said. They’re “probably not generalizable to a community setting where we see lots of missed diagnoses and delayed diagnoses,” as well as other tick-borne coinfections.
One of the challenges in designing future trials, in fact, relates to enrollment criteria and whether to use strict inclusion and exclusion criteria associated with the IDSA definition or take a broader approach to trial enrollment, he and others said. “You want to enroll patients for whom there’s no controversy that they’ve had Lyme infection ... for a study people believe in,” Dr. Aucott said during a discussion period, noting that it’s typical to screen over 100 patients to find one enrollee. “But it’s a tension we’re having.”
Timothy Sellati, PhD, chief scientific officer of the Global Lyme Alliance, urged change. “It’s really important to try to figure out how to alter our thinking on identifying and diagnosing chronic Lyme patients because they need to be recruited into clinical trials,” he said during his presentation.
“We think the best way to do this is to [develop and] employ composite diagnostic testing” that looks at unique Borrelia signatures (eg, protein, DNA, RNA, or metabolites), genetic and/or epigenetic signatures, inflammation signatures, T-cell-independent antibody signatures, and other elements, Dr. Sellati said.
Researchers designing treatment trials also face unknowns, Dr. Aucott and others said, about the role of potential mechanisms of Lyme IACI, from persistent Borrelia burgdorferi (or Borrelia mayonii) infection or the persistence of bacterial remnants (eg, nucleic acids or peptidoglycans) to infection-triggered pathology such as persistent immune dysregulation, chronic inflammation, autoimmunity, microbiome alterations, and dysautonomia and other neural network alterations.
The NASEM’s spotlight on Lyme IACI follows its long COVID-driven push last year to advance a common research agenda in infection-associated chronic illnesses. Investigators see common symptoms and potential shared mechanisms between long COVID, Lyme IACI, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and other complex chronic illnesses following infections.
At the Lyme IACI meeting, invited speakers described parts of the research landscape. Avindra Nath, MD, of the National Institute of Neurological Disorders and Stroke, for instance, described a recently published deep phenotyping study of 17 patients with ME/CFS that found decreased central catecholamine synthesis, circuit dysfunction of integrative brain regions, and immune profiling differences (eg, defects in B-cell maturation or T-cell exhaustion), compared with matched controls, that suggest the persistence of microbial antigens.
And John Leong, MD, PhD, of Tufts University, Boston, described his lab’s focus on understanding the microbe-host interactions that enable bloodstream dissemination and tissue invasion of B burgdorferi to take hold, increasing the risk for persistent symptoms. Other research at Tufts, he noted during a discussion period, has demonstrated the persistence of B burgdorferi to antibiotics in microtiter dishes. “Those organisms that survive are really difficult to eradicate in vitro,” Dr. Leong said.
Other physician investigators described research on nociplastic pain — a category of pain that can be triggered by infections, causing both amplified sensory processing and augmented central nervous system pain — and on whether reactivation of the Epstein-Barr virus could potentiate autoimmunity in the context of Borrelia infection.
Researchers are ready to test therapies while pathophysiology is unraveled — provided there is funding, Dr. Aucott said. The Clinical Trials Network for Lyme and Other Tick-Borne Diseases, coordinated by Brian Fallon, MD, of Columbia University, New York City, and funded several years ago by the Steven & Alexandra Cohen Foundation, has a slate of small pilot studies underway or being planned that address potential mechanisms (eg, studies of pulse intravenous ceftriaxone, tetracycline, transauricular vagus nerve stimulation, and mast cell modulation). And should full multisite trials be designed and funded, the network is ready with an infrastructure.
Need for Patient-Centered Outcomes
Persistent symptomatology is on the NIH’s radar screen. Efforts to understand causes were part of a strategic tick-borne disease research plan developed by the NIH in 2019. And in 2023, the National Institute of Allergy and Infectious Diseases (NIAID) funded seven projects addressing persistent symptoms that will run through 2028, C. Benjamin Beard, PhD, deputy division director of the CDC’s Division of Vector-Borne Disease, said at the NASEM committee meeting.
Patient advocates maintained that too much emphasis is placed on tick biology and pathophysiology. When Wendy Adams, research grant director and advisory board member of the Bay Area Lyme Foundation, and a colleague analyzed NIAID tick-borne disease funding from 2013 to 2021, they found that 75% of the funding went toward basic research, 15% to translational research, and “only 3% went to clinical research,” Ms. Adams told the committee.
Only 3% of the basic research budget was spent on coinfections, she said, and only 1% was spent on neurologic disease associated with tick-borne infections, both of which are survey-defined patient priorities. Moreover, “12% of the overall NIAID [tick-borne diseases] budget was spent on tick biology,” she said.
Research needs to involve community physicians who are utilizing the guidelines and approaches of the International Lyme and Associated Diseases Society to treat most patients with Lyme IACI, Ms. Adams said. “They have data to be mined,” she said, as does LymeDisease.org, which maintains a patient registry, MyLymeData, with over 18,000 patients. The organization has published two treatment studies, including one on antibiotic treatment response.
Lorraine Johnson, JD, MBA, CEO of LymeDisease.org and principal investigator of MyLymeData, stressed the importance of using patient-centered outcomes that incorporate minimal clinically important differences (MCIDs). “A change in the SF-36 score [without consideration of MCIDs] is not inherently important or meaningful to patients,” she said, referring to the SF-36 survey of health-related quality of life.
“This may seem like an esoteric issue, but two of the four clinical trials done [on retreatment of] persistent Lyme disease used the SF-36 as their outcome measure, and those studies, led by [Mark] Klempner, concluded that retreatment was not effective,” Ms. Johnson said. “Patients have been and continue to be harmed by [this research] because they’re told by physicians that antibiotics don’t work.”
A 2012 biostatistical review of these four RCTs — trials that helped inform the 2006 IDSA treatment guidelines — concluded that the Klempner studies “set the bar for treatment success too high,” Ms. Johnson said. Three of the four trials were likely underpowered to detect clinically meaningful treatment effects, the review also found.
The NASEM committee will hold additional public meetings and review a wide range of literature through this year. The formation of the committee was recommended by the US Department of Health and Human Services Tick-Borne Disease Working Group that was established by Congress in 2016 and concluded its work in 2022. The committee’s work is funded by the Cohen Foundation.
A version of this article appeared on Medscape.com.
Moderate Exercise in Midlife Linked to Lower Risk for ALS
Moderate exercise in midlife is associated with a reduced risk for amyotrophic lateral sclerosis (ALS) later in life, but this benefit appears to be limited to men, findings from a large prospective study showed.
Men who reported moderate levels of physical activity had a 29% lower risk for ALS, whereas those with high levels of physical activity had a 41% lower risk for the disease.
The findings were published online in Neurology.
Conflicting Findings
Several famous athletes have died of ALS, including the baseball player Lou Gehrig (for whom the disease is named), football players Dwight Clark, Steve Gleason, and Kevin Turner, and the boxer Ezzard Charles. This has led some scientists to speculate that intense physical activity may play a role in the development of the disease.
Anders M. Vaage, MD, noted there have been conflicting findings in previous studies on the topic, with results showing both increased and reduced ALS risks with increasing levels of physical activity.
In one study, researchers followed more than 212,000 Swedish cross-country skiers and more than 500,000 Swedish individuals in the general population for 20 years and found that strenuous cross-country skiing was associated with a higher risk for ALS but only among the best skiers; recreational skiers appeared to have a reduced risk.
“Our study does not necessarily contradict previous studies with findings of an increased ALS risk with extreme or intense levels of physical activity in athletes, as this study reflects more moderate levels of physical activity and fitness in the total population,” said Dr. Vaage.
To further explore the association, the researchers followed 373,700 individuals who participated in a cardiovascular health survey for an average of 27 years. When the survey began, most participants were 40-42 years old.
Participants were followed until the date of ALS diagnosis, ALS death, death from other causes, emigration, or the end of study in August 2021.
Participants answered questions about physical activity levels, smoking status, and other issues relating to cardiovascular health, and participants’ resting heart rate was measured and divided into quartiles of 31-65 beats per minute (BPM), 66-74 BPM, 75-81 BPM, or 82-100 BPM.
Participants self-reported their physical activity over the past year, classifying it into one of four categories: Sedentary, at least 4 hours per week of walking or cycling, at least 4 hours per week of recreational sports or heavy gardening, or regular participation in intense training or sports competitions several times per week.
Only a few participants reported the highest level of physical activity, so researchers combined the third and fourth categories into a single high-activity group.
Of the total study cohort, 504 participants developed ALS. Of those who developed the disease, 59% were men.
Researchers found that of the 41,898 male participants with the highest level of physical activity, 63 developed ALS. In comparison, of the 76,769 male participants who reported an intermediate level of physical activity, 131 developed ALS. Among the 29,468 male participants who reported the lowest level of physical activity, 68 developed ALS.
No Link in Women?
After adjusting for smoking, body mass index, and other risk factors, investigators found that men with moderate physical activity levels had a 29% lower risk for ALS compared with those with low physical activity levels, whereas those with the highest activity levels had a 41% lower risk.
In addition, men in the lowest of the four categories of resting heart rate had a 32% reduced risk for ALS compared with men with a higher resting heart rate.
Investigators are unclear why there was a lack of association between physical activity and resting heart rate and ALS risk in women.
“There are known sex differences in ALS, which includes a sex ratio with male preponderance, and there are also sex differences in response to physical exercise. Perhaps underlying mechanisms herein can explain the difference observed between males and females in the study,” Dr. Vaage said. He noted that future research should explore this difference.
Study limitations included the absence of data on physical trauma and head trauma, which have been linked with increased ALS risk. In addition, there were no data on genotype.
In an accompanying editorial, Pamela Shaw, MD, and Johnathan Cooper-Knock, BMBCh, PhD, of the University of Sheffield, Sheffield, England, described the research as a “valuable contribution to the field and potentially provides some reassurance that mild/moderate levels of physical activity in middle age do not increase the risk for ALS but may instead have a beneficial protective effect.”
Future research on exercise in ALS, they add, should consider sex differences, capture the most extreme physical activity levels, and identify any genetic factors that may mediate the association between intense exercise and ALS.
No targeted funding was reported. Dr. Vaage reported receiving funding from ALS Laboratory Group Norway.
A version of this article first appeared on Medscape.com.
Moderate exercise in midlife is associated with a reduced risk for amyotrophic lateral sclerosis (ALS) later in life, but this benefit appears to be limited to men, findings from a large prospective study showed.
Men who reported moderate levels of physical activity had a 29% lower risk for ALS, whereas those with high levels of physical activity had a 41% lower risk for the disease.
The findings were published online in Neurology.
Conflicting Findings
Several famous athletes have died of ALS, including the baseball player Lou Gehrig (for whom the disease is named), football players Dwight Clark, Steve Gleason, and Kevin Turner, and the boxer Ezzard Charles. This has led some scientists to speculate that intense physical activity may play a role in the development of the disease.
Anders M. Vaage, MD, noted there have been conflicting findings in previous studies on the topic, with results showing both increased and reduced ALS risks with increasing levels of physical activity.
In one study, researchers followed more than 212,000 Swedish cross-country skiers and more than 500,000 Swedish individuals in the general population for 20 years and found that strenuous cross-country skiing was associated with a higher risk for ALS but only among the best skiers; recreational skiers appeared to have a reduced risk.
“Our study does not necessarily contradict previous studies with findings of an increased ALS risk with extreme or intense levels of physical activity in athletes, as this study reflects more moderate levels of physical activity and fitness in the total population,” said Dr. Vaage.
To further explore the association, the researchers followed 373,700 individuals who participated in a cardiovascular health survey for an average of 27 years. When the survey began, most participants were 40-42 years old.
Participants were followed until the date of ALS diagnosis, ALS death, death from other causes, emigration, or the end of study in August 2021.
Participants answered questions about physical activity levels, smoking status, and other issues relating to cardiovascular health, and participants’ resting heart rate was measured and divided into quartiles of 31-65 beats per minute (BPM), 66-74 BPM, 75-81 BPM, or 82-100 BPM.
Participants self-reported their physical activity over the past year, classifying it into one of four categories: Sedentary, at least 4 hours per week of walking or cycling, at least 4 hours per week of recreational sports or heavy gardening, or regular participation in intense training or sports competitions several times per week.
Only a few participants reported the highest level of physical activity, so researchers combined the third and fourth categories into a single high-activity group.
Of the total study cohort, 504 participants developed ALS. Of those who developed the disease, 59% were men.
Researchers found that of the 41,898 male participants with the highest level of physical activity, 63 developed ALS. In comparison, of the 76,769 male participants who reported an intermediate level of physical activity, 131 developed ALS. Among the 29,468 male participants who reported the lowest level of physical activity, 68 developed ALS.
No Link in Women?
After adjusting for smoking, body mass index, and other risk factors, investigators found that men with moderate physical activity levels had a 29% lower risk for ALS compared with those with low physical activity levels, whereas those with the highest activity levels had a 41% lower risk.
In addition, men in the lowest of the four categories of resting heart rate had a 32% reduced risk for ALS compared with men with a higher resting heart rate.
Investigators are unclear why there was a lack of association between physical activity and resting heart rate and ALS risk in women.
“There are known sex differences in ALS, which includes a sex ratio with male preponderance, and there are also sex differences in response to physical exercise. Perhaps underlying mechanisms herein can explain the difference observed between males and females in the study,” Dr. Vaage said. He noted that future research should explore this difference.
Study limitations included the absence of data on physical trauma and head trauma, which have been linked with increased ALS risk. In addition, there were no data on genotype.
In an accompanying editorial, Pamela Shaw, MD, and Johnathan Cooper-Knock, BMBCh, PhD, of the University of Sheffield, Sheffield, England, described the research as a “valuable contribution to the field and potentially provides some reassurance that mild/moderate levels of physical activity in middle age do not increase the risk for ALS but may instead have a beneficial protective effect.”
Future research on exercise in ALS, they add, should consider sex differences, capture the most extreme physical activity levels, and identify any genetic factors that may mediate the association between intense exercise and ALS.
No targeted funding was reported. Dr. Vaage reported receiving funding from ALS Laboratory Group Norway.
A version of this article first appeared on Medscape.com.
Moderate exercise in midlife is associated with a reduced risk for amyotrophic lateral sclerosis (ALS) later in life, but this benefit appears to be limited to men, findings from a large prospective study showed.
Men who reported moderate levels of physical activity had a 29% lower risk for ALS, whereas those with high levels of physical activity had a 41% lower risk for the disease.
The findings were published online in Neurology.
Conflicting Findings
Several famous athletes have died of ALS, including the baseball player Lou Gehrig (for whom the disease is named), football players Dwight Clark, Steve Gleason, and Kevin Turner, and the boxer Ezzard Charles. This has led some scientists to speculate that intense physical activity may play a role in the development of the disease.
Anders M. Vaage, MD, noted there have been conflicting findings in previous studies on the topic, with results showing both increased and reduced ALS risks with increasing levels of physical activity.
In one study, researchers followed more than 212,000 Swedish cross-country skiers and more than 500,000 Swedish individuals in the general population for 20 years and found that strenuous cross-country skiing was associated with a higher risk for ALS but only among the best skiers; recreational skiers appeared to have a reduced risk.
“Our study does not necessarily contradict previous studies with findings of an increased ALS risk with extreme or intense levels of physical activity in athletes, as this study reflects more moderate levels of physical activity and fitness in the total population,” said Dr. Vaage.
To further explore the association, the researchers followed 373,700 individuals who participated in a cardiovascular health survey for an average of 27 years. When the survey began, most participants were 40-42 years old.
Participants were followed until the date of ALS diagnosis, ALS death, death from other causes, emigration, or the end of study in August 2021.
Participants answered questions about physical activity levels, smoking status, and other issues relating to cardiovascular health, and participants’ resting heart rate was measured and divided into quartiles of 31-65 beats per minute (BPM), 66-74 BPM, 75-81 BPM, or 82-100 BPM.
Participants self-reported their physical activity over the past year, classifying it into one of four categories: Sedentary, at least 4 hours per week of walking or cycling, at least 4 hours per week of recreational sports or heavy gardening, or regular participation in intense training or sports competitions several times per week.
Only a few participants reported the highest level of physical activity, so researchers combined the third and fourth categories into a single high-activity group.
Of the total study cohort, 504 participants developed ALS. Of those who developed the disease, 59% were men.
Researchers found that of the 41,898 male participants with the highest level of physical activity, 63 developed ALS. In comparison, of the 76,769 male participants who reported an intermediate level of physical activity, 131 developed ALS. Among the 29,468 male participants who reported the lowest level of physical activity, 68 developed ALS.
No Link in Women?
After adjusting for smoking, body mass index, and other risk factors, investigators found that men with moderate physical activity levels had a 29% lower risk for ALS compared with those with low physical activity levels, whereas those with the highest activity levels had a 41% lower risk.
In addition, men in the lowest of the four categories of resting heart rate had a 32% reduced risk for ALS compared with men with a higher resting heart rate.
Investigators are unclear why there was a lack of association between physical activity and resting heart rate and ALS risk in women.
“There are known sex differences in ALS, which includes a sex ratio with male preponderance, and there are also sex differences in response to physical exercise. Perhaps underlying mechanisms herein can explain the difference observed between males and females in the study,” Dr. Vaage said. He noted that future research should explore this difference.
Study limitations included the absence of data on physical trauma and head trauma, which have been linked with increased ALS risk. In addition, there were no data on genotype.
In an accompanying editorial, Pamela Shaw, MD, and Johnathan Cooper-Knock, BMBCh, PhD, of the University of Sheffield, Sheffield, England, described the research as a “valuable contribution to the field and potentially provides some reassurance that mild/moderate levels of physical activity in middle age do not increase the risk for ALS but may instead have a beneficial protective effect.”
Future research on exercise in ALS, they add, should consider sex differences, capture the most extreme physical activity levels, and identify any genetic factors that may mediate the association between intense exercise and ALS.
No targeted funding was reported. Dr. Vaage reported receiving funding from ALS Laboratory Group Norway.
A version of this article first appeared on Medscape.com.
FROM NEUROLOGY
New Parkinson’s Disease Gene Discovered
HELSINKI, FINLAND — , a discovery that experts believe will have important clinical implications in the not-too-distant future.
A variant in PMSF1, a proteasome regulator, was identified in 15 families from 13 countries around the world, with 22 affected individuals.
“These families were ethnically diverse, and in all of them, the variant in PMSF1 correlated with the neurologic phenotype. We know this is very clear cut — the genotype/phenotype correlation — with the patients carrying the missense mutation having ‘mild’ symptoms, while those with the progressive loss-of-function variant had the most severe phenotype,” she noted.
“Our findings unequivocally link defective PSMF1 to early-onset PD and neurodegeneration and suggest mitochondrial dysfunction as a mechanistic contributor,” study investigator Francesca Magrinelli, MD, PhD, of University College London (UCL) Queen Square Institute of Neurology, UCL, London, told delegates at the 2024 Congress of the European Academy of Neurology.
Managing Patient Expectations
Those “mildly” affected had an early-onset Parkinson’s disease starting between the second and fifth decade of life with pyramidal tract signs, dysphasia, psychiatric comorbidity, and early levodopa-induced dyskinesia.
In those with the intermediate type, Parkinson’s disease symptoms start in childhood and include, among other things, global hypokinesia, developmental delay, cerebellar signs, and in some, associated epilepsy.
In most cases, there was evidence on brain MRI of a hypoplasia of the corpus callosum, Dr. Magrinelli said. In the most severely affected individuals, there was perinatal lethality with neurologic manifestations.
While it may seem that the genetics of Parkinson’s disease is an academic exercise for the most part, it won’t be too much longer before it yields practical information that will inform how patients are treated, said Parkinson’s disease expert Christine Klein, MD, of the Institute of Neurogenetics and Department of Neurology, University of Lübeck, Helsinki, Finland.
The genetics of Parkinson’s disease are complicated, even within a single family. So, it’s very important to assess the pathogenicity of different variants, Dr. Klein noted.
“I am sure that you have all had a Parkinson’s disease [gene] panel back, and it says, ‘variant of uncertain significance.’ This is the worst thing that can happen. The lab does not know what it means. You don’t know what it means, and you don’t know what to tell the patient. So how do you get around this?”
Dr. Klein said that before conducting any genetic testing, clinicians should inform the patient that they may have a genetic variant of uncertain significance. It doesn’t solve the problem, but it does help physicians manage patient expectations.
Clinical Relevance on the Way?
While it may seem that all of the identified variants that predict Parkinson’s disease which, in addition to PSMF1, include the well-established LRRK2 and GBA1, may look the same, this is not true when patient history is taken into account, said Dr. Klein.
For example, age-of-onset of Parkinson’s disease can differ between identified variants, and this has led to “a paradigm change” whereby a purely genetic finding is called a disease.
This first occurred in Huntington’s disease, when researchers gave individuals at high genetic risk of developing the illness, but who currently had no clinical symptoms, the label of “Stage Zero disease.”
This is important to note “because if we get to the stage of having drugs that can slow down, or even prevent, progression to Parkinson’s disease, then it will be key to have patients we know are going to develop it to participate in clinical trials for such agents,” said Dr. Klein.
She cited the example of a family that she recently encountered that had genetic test results that showed variants of unknown significance, so Dr. Klein had the family’s samples sent to a specialized lab in Dundee, Scotland, for further analysis.
“The biochemists found that this variant was indeed pathogenic, and kinase-activating, so this is very helpful and very important because there are now clinical trials in Parkinson’s disease with kinase inhibitors,” she noted.
“If you think there is something else [over and above the finding of uncertain significance] in your Parkinson’s disease panel, and you are not happy with the genetic report, send it somewhere else,” Dr. Klein advised.
“We will see a lot more patients with genetic Parkinson’s disease in the future,” she predicted, while citing two recent preliminary clinical trials that have shown some promise in terms of neuroprotection in patients with early Parkinson’s disease.
“It remains to be seen whether there will be light at the end of the tunnel,” she said, but it may soon be possible to find treatments that delay, or even prevent, Parkinson’s disease onset.
Dr. Magrinelli reported receiving speaker’s honoraria from MJFF Edmond J. Safra Clinical Research Fellowship in Movement Disorders (Class of 2023), MJFF Edmond J. Safra Movement Disorders Research Career Development Award 2023 (Grant ID MJFF-023893), American Parkinson Disease Association (Research Grant 2024), and the David Blank Charitable Foundation. Dr. Klein reported being a medical advisor to Retromer Therapeutics, Takeda, and Centogene and speakers’ honoraria from Desitin and Bial.
A version of this article first appeared on Medscape.com.
HELSINKI, FINLAND — , a discovery that experts believe will have important clinical implications in the not-too-distant future.
A variant in PMSF1, a proteasome regulator, was identified in 15 families from 13 countries around the world, with 22 affected individuals.
“These families were ethnically diverse, and in all of them, the variant in PMSF1 correlated with the neurologic phenotype. We know this is very clear cut — the genotype/phenotype correlation — with the patients carrying the missense mutation having ‘mild’ symptoms, while those with the progressive loss-of-function variant had the most severe phenotype,” she noted.
“Our findings unequivocally link defective PSMF1 to early-onset PD and neurodegeneration and suggest mitochondrial dysfunction as a mechanistic contributor,” study investigator Francesca Magrinelli, MD, PhD, of University College London (UCL) Queen Square Institute of Neurology, UCL, London, told delegates at the 2024 Congress of the European Academy of Neurology.
Managing Patient Expectations
Those “mildly” affected had an early-onset Parkinson’s disease starting between the second and fifth decade of life with pyramidal tract signs, dysphasia, psychiatric comorbidity, and early levodopa-induced dyskinesia.
In those with the intermediate type, Parkinson’s disease symptoms start in childhood and include, among other things, global hypokinesia, developmental delay, cerebellar signs, and in some, associated epilepsy.
In most cases, there was evidence on brain MRI of a hypoplasia of the corpus callosum, Dr. Magrinelli said. In the most severely affected individuals, there was perinatal lethality with neurologic manifestations.
While it may seem that the genetics of Parkinson’s disease is an academic exercise for the most part, it won’t be too much longer before it yields practical information that will inform how patients are treated, said Parkinson’s disease expert Christine Klein, MD, of the Institute of Neurogenetics and Department of Neurology, University of Lübeck, Helsinki, Finland.
The genetics of Parkinson’s disease are complicated, even within a single family. So, it’s very important to assess the pathogenicity of different variants, Dr. Klein noted.
“I am sure that you have all had a Parkinson’s disease [gene] panel back, and it says, ‘variant of uncertain significance.’ This is the worst thing that can happen. The lab does not know what it means. You don’t know what it means, and you don’t know what to tell the patient. So how do you get around this?”
Dr. Klein said that before conducting any genetic testing, clinicians should inform the patient that they may have a genetic variant of uncertain significance. It doesn’t solve the problem, but it does help physicians manage patient expectations.
Clinical Relevance on the Way?
While it may seem that all of the identified variants that predict Parkinson’s disease which, in addition to PSMF1, include the well-established LRRK2 and GBA1, may look the same, this is not true when patient history is taken into account, said Dr. Klein.
For example, age-of-onset of Parkinson’s disease can differ between identified variants, and this has led to “a paradigm change” whereby a purely genetic finding is called a disease.
This first occurred in Huntington’s disease, when researchers gave individuals at high genetic risk of developing the illness, but who currently had no clinical symptoms, the label of “Stage Zero disease.”
This is important to note “because if we get to the stage of having drugs that can slow down, or even prevent, progression to Parkinson’s disease, then it will be key to have patients we know are going to develop it to participate in clinical trials for such agents,” said Dr. Klein.
She cited the example of a family that she recently encountered that had genetic test results that showed variants of unknown significance, so Dr. Klein had the family’s samples sent to a specialized lab in Dundee, Scotland, for further analysis.
“The biochemists found that this variant was indeed pathogenic, and kinase-activating, so this is very helpful and very important because there are now clinical trials in Parkinson’s disease with kinase inhibitors,” she noted.
“If you think there is something else [over and above the finding of uncertain significance] in your Parkinson’s disease panel, and you are not happy with the genetic report, send it somewhere else,” Dr. Klein advised.
“We will see a lot more patients with genetic Parkinson’s disease in the future,” she predicted, while citing two recent preliminary clinical trials that have shown some promise in terms of neuroprotection in patients with early Parkinson’s disease.
“It remains to be seen whether there will be light at the end of the tunnel,” she said, but it may soon be possible to find treatments that delay, or even prevent, Parkinson’s disease onset.
Dr. Magrinelli reported receiving speaker’s honoraria from MJFF Edmond J. Safra Clinical Research Fellowship in Movement Disorders (Class of 2023), MJFF Edmond J. Safra Movement Disorders Research Career Development Award 2023 (Grant ID MJFF-023893), American Parkinson Disease Association (Research Grant 2024), and the David Blank Charitable Foundation. Dr. Klein reported being a medical advisor to Retromer Therapeutics, Takeda, and Centogene and speakers’ honoraria from Desitin and Bial.
A version of this article first appeared on Medscape.com.
HELSINKI, FINLAND — , a discovery that experts believe will have important clinical implications in the not-too-distant future.
A variant in PMSF1, a proteasome regulator, was identified in 15 families from 13 countries around the world, with 22 affected individuals.
“These families were ethnically diverse, and in all of them, the variant in PMSF1 correlated with the neurologic phenotype. We know this is very clear cut — the genotype/phenotype correlation — with the patients carrying the missense mutation having ‘mild’ symptoms, while those with the progressive loss-of-function variant had the most severe phenotype,” she noted.
“Our findings unequivocally link defective PSMF1 to early-onset PD and neurodegeneration and suggest mitochondrial dysfunction as a mechanistic contributor,” study investigator Francesca Magrinelli, MD, PhD, of University College London (UCL) Queen Square Institute of Neurology, UCL, London, told delegates at the 2024 Congress of the European Academy of Neurology.
Managing Patient Expectations
Those “mildly” affected had an early-onset Parkinson’s disease starting between the second and fifth decade of life with pyramidal tract signs, dysphasia, psychiatric comorbidity, and early levodopa-induced dyskinesia.
In those with the intermediate type, Parkinson’s disease symptoms start in childhood and include, among other things, global hypokinesia, developmental delay, cerebellar signs, and in some, associated epilepsy.
In most cases, there was evidence on brain MRI of a hypoplasia of the corpus callosum, Dr. Magrinelli said. In the most severely affected individuals, there was perinatal lethality with neurologic manifestations.
While it may seem that the genetics of Parkinson’s disease is an academic exercise for the most part, it won’t be too much longer before it yields practical information that will inform how patients are treated, said Parkinson’s disease expert Christine Klein, MD, of the Institute of Neurogenetics and Department of Neurology, University of Lübeck, Helsinki, Finland.
The genetics of Parkinson’s disease are complicated, even within a single family. So, it’s very important to assess the pathogenicity of different variants, Dr. Klein noted.
“I am sure that you have all had a Parkinson’s disease [gene] panel back, and it says, ‘variant of uncertain significance.’ This is the worst thing that can happen. The lab does not know what it means. You don’t know what it means, and you don’t know what to tell the patient. So how do you get around this?”
Dr. Klein said that before conducting any genetic testing, clinicians should inform the patient that they may have a genetic variant of uncertain significance. It doesn’t solve the problem, but it does help physicians manage patient expectations.
Clinical Relevance on the Way?
While it may seem that all of the identified variants that predict Parkinson’s disease which, in addition to PSMF1, include the well-established LRRK2 and GBA1, may look the same, this is not true when patient history is taken into account, said Dr. Klein.
For example, age-of-onset of Parkinson’s disease can differ between identified variants, and this has led to “a paradigm change” whereby a purely genetic finding is called a disease.
This first occurred in Huntington’s disease, when researchers gave individuals at high genetic risk of developing the illness, but who currently had no clinical symptoms, the label of “Stage Zero disease.”
This is important to note “because if we get to the stage of having drugs that can slow down, or even prevent, progression to Parkinson’s disease, then it will be key to have patients we know are going to develop it to participate in clinical trials for such agents,” said Dr. Klein.
She cited the example of a family that she recently encountered that had genetic test results that showed variants of unknown significance, so Dr. Klein had the family’s samples sent to a specialized lab in Dundee, Scotland, for further analysis.
“The biochemists found that this variant was indeed pathogenic, and kinase-activating, so this is very helpful and very important because there are now clinical trials in Parkinson’s disease with kinase inhibitors,” she noted.
“If you think there is something else [over and above the finding of uncertain significance] in your Parkinson’s disease panel, and you are not happy with the genetic report, send it somewhere else,” Dr. Klein advised.
“We will see a lot more patients with genetic Parkinson’s disease in the future,” she predicted, while citing two recent preliminary clinical trials that have shown some promise in terms of neuroprotection in patients with early Parkinson’s disease.
“It remains to be seen whether there will be light at the end of the tunnel,” she said, but it may soon be possible to find treatments that delay, or even prevent, Parkinson’s disease onset.
Dr. Magrinelli reported receiving speaker’s honoraria from MJFF Edmond J. Safra Clinical Research Fellowship in Movement Disorders (Class of 2023), MJFF Edmond J. Safra Movement Disorders Research Career Development Award 2023 (Grant ID MJFF-023893), American Parkinson Disease Association (Research Grant 2024), and the David Blank Charitable Foundation. Dr. Klein reported being a medical advisor to Retromer Therapeutics, Takeda, and Centogene and speakers’ honoraria from Desitin and Bial.
A version of this article first appeared on Medscape.com.
FROM EAN 2024
Form of B12 Deficiency Affecting the Central Nervous System May Be New Autoimmune Disease
Discovered while studying a puzzling case of one patient with inexplicable neurological systems, the same autoantibody was detected in a small percentage of healthy individuals and was nearly four times as prevalent in patients with neuropsychiatric systemic lupus erythematosus (SLE).
“I didn’t think this single investigation was going to yield a broader phenomenon with other patients,” lead author John V. Pluvinage, MD, PhD, a neurology resident at the University of California San Francisco, said in an interview. “It started as an N-of-one study just based on scientific curiosity.”
“It’s a beautifully done study,” added Betty Diamond, MD, director of the Institute of Molecular Medicine at the Feinstein Institutes for Medical Research in Manhasset, New York, commenting on the research. It uncovers “yet another example of a disease where antibodies getting into the brain are the problem.”
The research was published in Science Translational Medicine.
The Patient
The investigation began in 2014 with a 67-year-old woman presenting with difficulty speaking, ataxia, and tremor. Her blood tests showed no signs of B12 deficiency, and testing for known autoantibodies came back negative.
Solving this mystery required a more exhaustive approach. The patient enrolled in a research study focused on identifying novel autoantibodies in suspected neuroinflammatory disease, using a screening technology called phage immunoprecipitation sequencing.
“We adapted this technology to screen for autoantibodies in an unbiased manner by displaying every peptide across the human proteome and then mixing those peptides with patient antibodies in order to figure out what the antibodies are binding to,” explained Dr. Pluvinage.
Using this method, he and colleagues discovered that this woman had autoantibodies that target CD320 — a receptor important in the cellular uptake of B12. While her blood tests were normal, B12 in the patient’s cerebral spinal fluid (CSF) was “nearly undetectable,” Dr. Pluvinage said. Using an in vitro model of the blood-brain barrier (BBB), the researchers determined that anti-CD320 impaired the transport of B12 across the BBB by targeting receptors on the cell surface.
Treating the patient with a combination of immunosuppressant medication and high-dose B12 supplementation increased B12 levels in the patient’s CSF and improved clinical symptoms.
Identifying More Cases
Dr. Pluvinage and colleagues tested the 254 other individuals enrolled in the neuroinflammatory disease study and identified seven participants with CSF anti-CD320 autoantibodies — four of whom had low B12 in the CSF.
In a group of healthy controls, anti-CD320 seropositivity was 6%, similar to the positivity rate in 132 paired serum and CSF samples from a cohort of patients with multiple sclerosis (5.7%). In this group of patients with multiple sclerosis, anti-CD320 presence in the blood was highly predictive of high levels of CSF methylmalonic acid, a metabolic marker of B12 deficiency.
Researchers also screened for anti-CD320 seropositivity in 408 patients with non-neurologic SLE and 28 patients with neuropsychiatric SLE and found that the autoantibody was nearly four times as prevalent in patients with neurologic symptoms (21.4%) compared with in those with non-neurologic SLE (5.6%).
“The clinical relevance of anti-CD320 in healthy controls remains uncertain,” the authors wrote. However, it is not uncommon to have healthy patients with known autoantibodies.
“There are always people who have autoantibodies who don’t get disease, and why that is we don’t know,” said Dr. Diamond. Some individuals may develop clinical symptoms later, or there may be other reasons why they are protected against disease.
Pluvinage is eager to follow some seropositive healthy individuals to track their neurologic health overtime, to see if the presence of anti-CD320 “alters their neurologic trajectories.”
Alternative Pathways
Lastly, Dr. Pluvinage and colleagues set out to explain why patients with anti-CD320 in their blood did not show any signs of B12 deficiency. They hypothesized that another receptor may be compensating and still allowing blood cells to take up B12. Using CRISPR screening, the team identified the low-density lipoprotein receptor as an alternative pathway to B12 uptake.
“These findings suggest a model in which anti-CD320 impairs transport of B12 across the BBB, leading to autoimmune B12 central deficiency (ABCD) with varied neurologic manifestations but sparing peripheral manifestations of B12 deficiency,” the authors wrote.
The work was supported by the National Institute of Mental Health, National Center for Chronic Disease Prevention and Health Promotion, Department of Defense, UCSF Helen Diller Family Comprehensive Cancer Center Laboratory for Cell Analysis Shared Resource Facility, National Multiple Sclerosis Society, Valhalla Foundation, and the Westridge Foundation. Dr. Pluvinage is a co-inventor on a patent application related to this work. Dr. Diamond had no relevant disclosures.
A version of this article first appeared on Medscape.com.
Discovered while studying a puzzling case of one patient with inexplicable neurological systems, the same autoantibody was detected in a small percentage of healthy individuals and was nearly four times as prevalent in patients with neuropsychiatric systemic lupus erythematosus (SLE).
“I didn’t think this single investigation was going to yield a broader phenomenon with other patients,” lead author John V. Pluvinage, MD, PhD, a neurology resident at the University of California San Francisco, said in an interview. “It started as an N-of-one study just based on scientific curiosity.”
“It’s a beautifully done study,” added Betty Diamond, MD, director of the Institute of Molecular Medicine at the Feinstein Institutes for Medical Research in Manhasset, New York, commenting on the research. It uncovers “yet another example of a disease where antibodies getting into the brain are the problem.”
The research was published in Science Translational Medicine.
The Patient
The investigation began in 2014 with a 67-year-old woman presenting with difficulty speaking, ataxia, and tremor. Her blood tests showed no signs of B12 deficiency, and testing for known autoantibodies came back negative.
Solving this mystery required a more exhaustive approach. The patient enrolled in a research study focused on identifying novel autoantibodies in suspected neuroinflammatory disease, using a screening technology called phage immunoprecipitation sequencing.
“We adapted this technology to screen for autoantibodies in an unbiased manner by displaying every peptide across the human proteome and then mixing those peptides with patient antibodies in order to figure out what the antibodies are binding to,” explained Dr. Pluvinage.
Using this method, he and colleagues discovered that this woman had autoantibodies that target CD320 — a receptor important in the cellular uptake of B12. While her blood tests were normal, B12 in the patient’s cerebral spinal fluid (CSF) was “nearly undetectable,” Dr. Pluvinage said. Using an in vitro model of the blood-brain barrier (BBB), the researchers determined that anti-CD320 impaired the transport of B12 across the BBB by targeting receptors on the cell surface.
Treating the patient with a combination of immunosuppressant medication and high-dose B12 supplementation increased B12 levels in the patient’s CSF and improved clinical symptoms.
Identifying More Cases
Dr. Pluvinage and colleagues tested the 254 other individuals enrolled in the neuroinflammatory disease study and identified seven participants with CSF anti-CD320 autoantibodies — four of whom had low B12 in the CSF.
In a group of healthy controls, anti-CD320 seropositivity was 6%, similar to the positivity rate in 132 paired serum and CSF samples from a cohort of patients with multiple sclerosis (5.7%). In this group of patients with multiple sclerosis, anti-CD320 presence in the blood was highly predictive of high levels of CSF methylmalonic acid, a metabolic marker of B12 deficiency.
Researchers also screened for anti-CD320 seropositivity in 408 patients with non-neurologic SLE and 28 patients with neuropsychiatric SLE and found that the autoantibody was nearly four times as prevalent in patients with neurologic symptoms (21.4%) compared with in those with non-neurologic SLE (5.6%).
“The clinical relevance of anti-CD320 in healthy controls remains uncertain,” the authors wrote. However, it is not uncommon to have healthy patients with known autoantibodies.
“There are always people who have autoantibodies who don’t get disease, and why that is we don’t know,” said Dr. Diamond. Some individuals may develop clinical symptoms later, or there may be other reasons why they are protected against disease.
Pluvinage is eager to follow some seropositive healthy individuals to track their neurologic health overtime, to see if the presence of anti-CD320 “alters their neurologic trajectories.”
Alternative Pathways
Lastly, Dr. Pluvinage and colleagues set out to explain why patients with anti-CD320 in their blood did not show any signs of B12 deficiency. They hypothesized that another receptor may be compensating and still allowing blood cells to take up B12. Using CRISPR screening, the team identified the low-density lipoprotein receptor as an alternative pathway to B12 uptake.
“These findings suggest a model in which anti-CD320 impairs transport of B12 across the BBB, leading to autoimmune B12 central deficiency (ABCD) with varied neurologic manifestations but sparing peripheral manifestations of B12 deficiency,” the authors wrote.
The work was supported by the National Institute of Mental Health, National Center for Chronic Disease Prevention and Health Promotion, Department of Defense, UCSF Helen Diller Family Comprehensive Cancer Center Laboratory for Cell Analysis Shared Resource Facility, National Multiple Sclerosis Society, Valhalla Foundation, and the Westridge Foundation. Dr. Pluvinage is a co-inventor on a patent application related to this work. Dr. Diamond had no relevant disclosures.
A version of this article first appeared on Medscape.com.
Discovered while studying a puzzling case of one patient with inexplicable neurological systems, the same autoantibody was detected in a small percentage of healthy individuals and was nearly four times as prevalent in patients with neuropsychiatric systemic lupus erythematosus (SLE).
“I didn’t think this single investigation was going to yield a broader phenomenon with other patients,” lead author John V. Pluvinage, MD, PhD, a neurology resident at the University of California San Francisco, said in an interview. “It started as an N-of-one study just based on scientific curiosity.”
“It’s a beautifully done study,” added Betty Diamond, MD, director of the Institute of Molecular Medicine at the Feinstein Institutes for Medical Research in Manhasset, New York, commenting on the research. It uncovers “yet another example of a disease where antibodies getting into the brain are the problem.”
The research was published in Science Translational Medicine.
The Patient
The investigation began in 2014 with a 67-year-old woman presenting with difficulty speaking, ataxia, and tremor. Her blood tests showed no signs of B12 deficiency, and testing for known autoantibodies came back negative.
Solving this mystery required a more exhaustive approach. The patient enrolled in a research study focused on identifying novel autoantibodies in suspected neuroinflammatory disease, using a screening technology called phage immunoprecipitation sequencing.
“We adapted this technology to screen for autoantibodies in an unbiased manner by displaying every peptide across the human proteome and then mixing those peptides with patient antibodies in order to figure out what the antibodies are binding to,” explained Dr. Pluvinage.
Using this method, he and colleagues discovered that this woman had autoantibodies that target CD320 — a receptor important in the cellular uptake of B12. While her blood tests were normal, B12 in the patient’s cerebral spinal fluid (CSF) was “nearly undetectable,” Dr. Pluvinage said. Using an in vitro model of the blood-brain barrier (BBB), the researchers determined that anti-CD320 impaired the transport of B12 across the BBB by targeting receptors on the cell surface.
Treating the patient with a combination of immunosuppressant medication and high-dose B12 supplementation increased B12 levels in the patient’s CSF and improved clinical symptoms.
Identifying More Cases
Dr. Pluvinage and colleagues tested the 254 other individuals enrolled in the neuroinflammatory disease study and identified seven participants with CSF anti-CD320 autoantibodies — four of whom had low B12 in the CSF.
In a group of healthy controls, anti-CD320 seropositivity was 6%, similar to the positivity rate in 132 paired serum and CSF samples from a cohort of patients with multiple sclerosis (5.7%). In this group of patients with multiple sclerosis, anti-CD320 presence in the blood was highly predictive of high levels of CSF methylmalonic acid, a metabolic marker of B12 deficiency.
Researchers also screened for anti-CD320 seropositivity in 408 patients with non-neurologic SLE and 28 patients with neuropsychiatric SLE and found that the autoantibody was nearly four times as prevalent in patients with neurologic symptoms (21.4%) compared with in those with non-neurologic SLE (5.6%).
“The clinical relevance of anti-CD320 in healthy controls remains uncertain,” the authors wrote. However, it is not uncommon to have healthy patients with known autoantibodies.
“There are always people who have autoantibodies who don’t get disease, and why that is we don’t know,” said Dr. Diamond. Some individuals may develop clinical symptoms later, or there may be other reasons why they are protected against disease.
Pluvinage is eager to follow some seropositive healthy individuals to track their neurologic health overtime, to see if the presence of anti-CD320 “alters their neurologic trajectories.”
Alternative Pathways
Lastly, Dr. Pluvinage and colleagues set out to explain why patients with anti-CD320 in their blood did not show any signs of B12 deficiency. They hypothesized that another receptor may be compensating and still allowing blood cells to take up B12. Using CRISPR screening, the team identified the low-density lipoprotein receptor as an alternative pathway to B12 uptake.
“These findings suggest a model in which anti-CD320 impairs transport of B12 across the BBB, leading to autoimmune B12 central deficiency (ABCD) with varied neurologic manifestations but sparing peripheral manifestations of B12 deficiency,” the authors wrote.
The work was supported by the National Institute of Mental Health, National Center for Chronic Disease Prevention and Health Promotion, Department of Defense, UCSF Helen Diller Family Comprehensive Cancer Center Laboratory for Cell Analysis Shared Resource Facility, National Multiple Sclerosis Society, Valhalla Foundation, and the Westridge Foundation. Dr. Pluvinage is a co-inventor on a patent application related to this work. Dr. Diamond had no relevant disclosures.
A version of this article first appeared on Medscape.com.
FROM SCIENCE TRANSLATIONAL MEDICINE
Magnesium Sulfate’s Ability to Reduce Cerebral Palsy in Preterm Birth Reaffirmed
An updated Cochrane Systematic Review of magnesium sulfate administered before preterm birth for neuroprotection has reaffirmed that the compound significantly reduces the risk of cerebral palsy and has added the finding that it also may reduce the risk of severe neonatal intraventricular hemorrhage.
Still unknown, however, is whether the effects of magnesium sulfate vary according to patient characteristics such as gestational age, or by treatment characteristics such as timing and dose. “We need further research to determine exactly who to treat, and when and how, to ideally standardize clinical practice recommendations across the world,” said Emily S. Shepherd, PhD, lead author of the review.
Magnesium sulfate is widely used for preterm cerebral palsy prevention but variance in national and local recommendations for its use may impede its optimal uptake in some places, she and her co-investigators wrote in the review.
In the United States, the American College of Obstetricians and Gynecologists advises institutions to develop their own guidelines regarding inclusion criteria and treatment regimens “in accordance with one of the larger trials.” (ACOG’s Committee Opinion on Magnesium Sulfate Before Anticipated Preterm Birth for Neuroprotection was originally published in 2010 and was reaffirmed in 2023.)
In a Master Class column on magnesium sulfate for neuroprotection published earlier this year in Ob.Gyn. News, Irina Burd, MD, PhD, wrote that most hospitals in the United States have chosen a higher dose of magnesium sulfate administered up to 31 weeks’ gestation (6-g bolus, followed by 2 g/hour), in keeping with the protocols used in the BEAM trial published by the National Institute of Child Health and Human Development (NICHD). Dr. Burd is the Sylvan Frieman, MD, Endowed Professor and chair of the department of obstetrics, gynecology and reproductive sciences at the University of Maryland School of Medicine, Baltimore, Maryland.
The new Cochrane review included six randomized controlled trials (including the NICHD trial) covering 5917 pregnant participants and 6759 fetuses. Eligibility criteria varied, but all the RCTs included patients in preterm labor or with expected or planned imminent preterm birth at less than 34 weeks’ gestation.
Treatment regimens varied: three trials administered a 4-g loading dose only, and three included a maintenance dose (a 4-6-g loading dose and a 1-2 g/hour maintenance dose). “Although we attempted to explore variation through subgroup analyses, the ability to do this was limited,” the researchers wrote.
Up to 2 years of corrected age, magnesium sulfate reduced the risk of cerebral palsy compared with placebo (relative risk, 0.71; 95% confidence interval (CI), 0.57-0.89) and death or cerebral palsy (RR, 0.87; 95% CI, 0.77-0.98), with a high-certainty grade of evidence. The number needed to treat to prevent one case of cerebral palsy was 60 and the number needed to treat death or cerebral palsy was 56. The impact on severe intracranial hemorrhage (RR, 0.76; 95% CI, 0.60-0.98), a secondary outcome, was backed by moderate-certainty evidence.
Compared with the 2009 Cochrane review, the new study includes two new randomized controlled trials. One of which, the MAGENTA trial, administered magnesium sulfate at 30-34 weeks gestation and included new school-age follow-up data from two previously included trials. While the available data suggest little to no difference in outcomes at school age, more follow-up data are needed to assess this with greater certainty, the reviewers wrote.
While severe adverse outcomes (death, cardiac or respiratory arrest) for pregnant individuals appear not to have increased in pregnant patients who received magnesium sulfate (low-certainty evidence), the compound “probably increased maternal adverse effects severe enough to stop treatment,” the reviewers report (average RR, 3.21; 95% CI, 1.88-5.48; moderate-certainty evidence).
Side effects that were more frequent among women receiving magnesium sulfate include hypotension, tachycardia, warmth over body/flushing, nausea or vomiting, sweating, and dizziness.
“Treatment cessation due to such side effects was in the context of trials being conducted to establish benefit,” noted Dr. Shepherd, of the University of Adelaide in Australia. “With benefit now shown, these side effects may be viewed as comparatively minor/generally tolerable considering the potential benefits for children.”
Proving the neuroprotective value of magnesium sulfate took many years, Dr. Burd explained in the Master Class, as none of the randomized controlled trials analyzed in eventual meta-analyses and systematic reviews had reached their primary endpoints. It wasn’t until researchers obtained unpublished data and conducted these analyses and reviews that a significant effect of magnesium sulfate on cerebral palsy could be seen. Dr. Burd and other researchers are now working to better understand its biologic plausibility and precise mechanisms of action.
Dr. Shepherd disclosed that she is a former editor for Cochrane Pregnancy and Childbirth and current sign-off editor for Cochrane Central Editorial Service but reported having no involvement in the editorial processing of the review. Other authors disclosed that they were investigators for included trials and/or have published opinions in medical journals related to magnesium sulfate to reduce cerebral palsy. Dr. Burd reported no disclosures.
An updated Cochrane Systematic Review of magnesium sulfate administered before preterm birth for neuroprotection has reaffirmed that the compound significantly reduces the risk of cerebral palsy and has added the finding that it also may reduce the risk of severe neonatal intraventricular hemorrhage.
Still unknown, however, is whether the effects of magnesium sulfate vary according to patient characteristics such as gestational age, or by treatment characteristics such as timing and dose. “We need further research to determine exactly who to treat, and when and how, to ideally standardize clinical practice recommendations across the world,” said Emily S. Shepherd, PhD, lead author of the review.
Magnesium sulfate is widely used for preterm cerebral palsy prevention but variance in national and local recommendations for its use may impede its optimal uptake in some places, she and her co-investigators wrote in the review.
In the United States, the American College of Obstetricians and Gynecologists advises institutions to develop their own guidelines regarding inclusion criteria and treatment regimens “in accordance with one of the larger trials.” (ACOG’s Committee Opinion on Magnesium Sulfate Before Anticipated Preterm Birth for Neuroprotection was originally published in 2010 and was reaffirmed in 2023.)
In a Master Class column on magnesium sulfate for neuroprotection published earlier this year in Ob.Gyn. News, Irina Burd, MD, PhD, wrote that most hospitals in the United States have chosen a higher dose of magnesium sulfate administered up to 31 weeks’ gestation (6-g bolus, followed by 2 g/hour), in keeping with the protocols used in the BEAM trial published by the National Institute of Child Health and Human Development (NICHD). Dr. Burd is the Sylvan Frieman, MD, Endowed Professor and chair of the department of obstetrics, gynecology and reproductive sciences at the University of Maryland School of Medicine, Baltimore, Maryland.
The new Cochrane review included six randomized controlled trials (including the NICHD trial) covering 5917 pregnant participants and 6759 fetuses. Eligibility criteria varied, but all the RCTs included patients in preterm labor or with expected or planned imminent preterm birth at less than 34 weeks’ gestation.
Treatment regimens varied: three trials administered a 4-g loading dose only, and three included a maintenance dose (a 4-6-g loading dose and a 1-2 g/hour maintenance dose). “Although we attempted to explore variation through subgroup analyses, the ability to do this was limited,” the researchers wrote.
Up to 2 years of corrected age, magnesium sulfate reduced the risk of cerebral palsy compared with placebo (relative risk, 0.71; 95% confidence interval (CI), 0.57-0.89) and death or cerebral palsy (RR, 0.87; 95% CI, 0.77-0.98), with a high-certainty grade of evidence. The number needed to treat to prevent one case of cerebral palsy was 60 and the number needed to treat death or cerebral palsy was 56. The impact on severe intracranial hemorrhage (RR, 0.76; 95% CI, 0.60-0.98), a secondary outcome, was backed by moderate-certainty evidence.
Compared with the 2009 Cochrane review, the new study includes two new randomized controlled trials. One of which, the MAGENTA trial, administered magnesium sulfate at 30-34 weeks gestation and included new school-age follow-up data from two previously included trials. While the available data suggest little to no difference in outcomes at school age, more follow-up data are needed to assess this with greater certainty, the reviewers wrote.
While severe adverse outcomes (death, cardiac or respiratory arrest) for pregnant individuals appear not to have increased in pregnant patients who received magnesium sulfate (low-certainty evidence), the compound “probably increased maternal adverse effects severe enough to stop treatment,” the reviewers report (average RR, 3.21; 95% CI, 1.88-5.48; moderate-certainty evidence).
Side effects that were more frequent among women receiving magnesium sulfate include hypotension, tachycardia, warmth over body/flushing, nausea or vomiting, sweating, and dizziness.
“Treatment cessation due to such side effects was in the context of trials being conducted to establish benefit,” noted Dr. Shepherd, of the University of Adelaide in Australia. “With benefit now shown, these side effects may be viewed as comparatively minor/generally tolerable considering the potential benefits for children.”
Proving the neuroprotective value of magnesium sulfate took many years, Dr. Burd explained in the Master Class, as none of the randomized controlled trials analyzed in eventual meta-analyses and systematic reviews had reached their primary endpoints. It wasn’t until researchers obtained unpublished data and conducted these analyses and reviews that a significant effect of magnesium sulfate on cerebral palsy could be seen. Dr. Burd and other researchers are now working to better understand its biologic plausibility and precise mechanisms of action.
Dr. Shepherd disclosed that she is a former editor for Cochrane Pregnancy and Childbirth and current sign-off editor for Cochrane Central Editorial Service but reported having no involvement in the editorial processing of the review. Other authors disclosed that they were investigators for included trials and/or have published opinions in medical journals related to magnesium sulfate to reduce cerebral palsy. Dr. Burd reported no disclosures.
An updated Cochrane Systematic Review of magnesium sulfate administered before preterm birth for neuroprotection has reaffirmed that the compound significantly reduces the risk of cerebral palsy and has added the finding that it also may reduce the risk of severe neonatal intraventricular hemorrhage.
Still unknown, however, is whether the effects of magnesium sulfate vary according to patient characteristics such as gestational age, or by treatment characteristics such as timing and dose. “We need further research to determine exactly who to treat, and when and how, to ideally standardize clinical practice recommendations across the world,” said Emily S. Shepherd, PhD, lead author of the review.
Magnesium sulfate is widely used for preterm cerebral palsy prevention but variance in national and local recommendations for its use may impede its optimal uptake in some places, she and her co-investigators wrote in the review.
In the United States, the American College of Obstetricians and Gynecologists advises institutions to develop their own guidelines regarding inclusion criteria and treatment regimens “in accordance with one of the larger trials.” (ACOG’s Committee Opinion on Magnesium Sulfate Before Anticipated Preterm Birth for Neuroprotection was originally published in 2010 and was reaffirmed in 2023.)
In a Master Class column on magnesium sulfate for neuroprotection published earlier this year in Ob.Gyn. News, Irina Burd, MD, PhD, wrote that most hospitals in the United States have chosen a higher dose of magnesium sulfate administered up to 31 weeks’ gestation (6-g bolus, followed by 2 g/hour), in keeping with the protocols used in the BEAM trial published by the National Institute of Child Health and Human Development (NICHD). Dr. Burd is the Sylvan Frieman, MD, Endowed Professor and chair of the department of obstetrics, gynecology and reproductive sciences at the University of Maryland School of Medicine, Baltimore, Maryland.
The new Cochrane review included six randomized controlled trials (including the NICHD trial) covering 5917 pregnant participants and 6759 fetuses. Eligibility criteria varied, but all the RCTs included patients in preterm labor or with expected or planned imminent preterm birth at less than 34 weeks’ gestation.
Treatment regimens varied: three trials administered a 4-g loading dose only, and three included a maintenance dose (a 4-6-g loading dose and a 1-2 g/hour maintenance dose). “Although we attempted to explore variation through subgroup analyses, the ability to do this was limited,” the researchers wrote.
Up to 2 years of corrected age, magnesium sulfate reduced the risk of cerebral palsy compared with placebo (relative risk, 0.71; 95% confidence interval (CI), 0.57-0.89) and death or cerebral palsy (RR, 0.87; 95% CI, 0.77-0.98), with a high-certainty grade of evidence. The number needed to treat to prevent one case of cerebral palsy was 60 and the number needed to treat death or cerebral palsy was 56. The impact on severe intracranial hemorrhage (RR, 0.76; 95% CI, 0.60-0.98), a secondary outcome, was backed by moderate-certainty evidence.
Compared with the 2009 Cochrane review, the new study includes two new randomized controlled trials. One of which, the MAGENTA trial, administered magnesium sulfate at 30-34 weeks gestation and included new school-age follow-up data from two previously included trials. While the available data suggest little to no difference in outcomes at school age, more follow-up data are needed to assess this with greater certainty, the reviewers wrote.
While severe adverse outcomes (death, cardiac or respiratory arrest) for pregnant individuals appear not to have increased in pregnant patients who received magnesium sulfate (low-certainty evidence), the compound “probably increased maternal adverse effects severe enough to stop treatment,” the reviewers report (average RR, 3.21; 95% CI, 1.88-5.48; moderate-certainty evidence).
Side effects that were more frequent among women receiving magnesium sulfate include hypotension, tachycardia, warmth over body/flushing, nausea or vomiting, sweating, and dizziness.
“Treatment cessation due to such side effects was in the context of trials being conducted to establish benefit,” noted Dr. Shepherd, of the University of Adelaide in Australia. “With benefit now shown, these side effects may be viewed as comparatively minor/generally tolerable considering the potential benefits for children.”
Proving the neuroprotective value of magnesium sulfate took many years, Dr. Burd explained in the Master Class, as none of the randomized controlled trials analyzed in eventual meta-analyses and systematic reviews had reached their primary endpoints. It wasn’t until researchers obtained unpublished data and conducted these analyses and reviews that a significant effect of magnesium sulfate on cerebral palsy could be seen. Dr. Burd and other researchers are now working to better understand its biologic plausibility and precise mechanisms of action.
Dr. Shepherd disclosed that she is a former editor for Cochrane Pregnancy and Childbirth and current sign-off editor for Cochrane Central Editorial Service but reported having no involvement in the editorial processing of the review. Other authors disclosed that they were investigators for included trials and/or have published opinions in medical journals related to magnesium sulfate to reduce cerebral palsy. Dr. Burd reported no disclosures.
COCHRANE DATABASE SYSTEMATIC REVIEW
Solving Restless Legs: Largest Genetic Study to Date May Help
For decades, scientists have been trying to unravel the mysteries of restless legs syndrome (RLS), a poorly understood and underdiagnosed neurological disorder causing itching, crawling, and aching sensations in the limbs that can only be relieved with movement.
A sweeping new genetic study, coauthored by an international team of 70 — including the world’s leading RLS experts — marks a significant advance in that pursuit. Published in Nature Genetics, it is the largest genetic study of the disease to date.
“It’s a huge step forward for patients as well as the scientific community,” said lead author Juliane Winkelmann, MD, a neurologist and geneticist with the Technical University of Munich, Munich, Germany, who’s been studying and treating patients with RLS for 30 years. “We believe it will allow us to better predict the likelihood of developing RLS and investigate new ways to prevent and modify it.”
The common condition, affecting about 1 in 10 adults, was first described centuries ago — by English physician Thomas Willis in the late 1600s. And while we know a lot more about it today — it’s familial in about half of all patients and has been linked to iron deficiency, among other conditions — its exact cause remains unknown.
With preferred drugs long prescribed to quell symptoms shown in recent years to actually worsen the disorder over time, doctors and patients are hungry for alternatives to treat or prevent the sleep-sabotaging condition.
“The main treatments that everybody continues to use are actually making people worse,” said Andrew Berkowski, MD, a Michigan-based neurologist and RLS specialist not involved in the study. These drugs — dopamine agonists such as levodopa and pramipexole — can also potentially cause drug dependence, Dr. Berkowski said.
How This Could Lead to New Treatments
In the new study, the group analyzed three genome-wide association studies, collectively including genetic information from 116,647 patients with RLS and more than 1.5 million people without it.
They identified 161 gene regions believed to contribute to RLS, about a dozen of which are already targets for existing drugs for other conditions. Previously, scientists knew of only 22 associated genes.
“It’s useful in that it identifies new genes we haven’t looked at yet and reinforces the science behind some of the older genes,” said Dr. Berkowski. “It’s given us some ideas for different things we should look into more closely.”
Among the top candidates are genes that influence glutamate — a key chemical messenger that helps move signals between nerve cells in the brain.
Several anticonvulsant and antiseizure drugs, including perampanel, lamotrigine, and gabapentin, target glutamate receptors. And at least one small study has shown perampanel prescribed off-label can improve RLS symptoms.
“Compared to starting at the beginning and developing an entirely new chemical entity, we could run clinical trials using these alternatives in RLS patients,” said the study’s first author, Steven Bell, PhD, an epidemiologist with the University of Cambridge, Cambridge, England.
The study also confirmed the MIES1 gene, which is related to dopamine expression and iron homeostasis, as a key genetic contributor to RLS risk. Low levels of iron in the blood have long been thought to trigger RLS.
The Role of Gene-Environment Interactions
Through additional data analysis, the team confirmed that many of the genes associated with RLS play a role in development of the central nervous system.
“This strongly supports the hypothesis that restless legs syndrome is a neurodevelopmental disorder that develops during the embryo stage but doesn’t clinically manifest until later in life,” said Dr. Winkelmann.
About half of people with RLS report some family history of it.
But not all with a genetic predisposition will develop symptoms.
For instance, the study found that while the same gene regions seem to be associated with risk in both men and women, in practice, RLS is twice as common among women. This suggests that something about women’s lives — menstruation, childbirth, metabolism — may switch a preexisting risk into a reality.
“We know that genetic factors play an important role in making people susceptible to the disease,” said Dr. Winkelmann, “but in the end, it is the interaction between genetic and environmental factors that may lead to its manifestation.”
The study also found associations between RLS and depression and suggests that RLS may increase the risk for type 2 diabetes.
Improving RLS Care
A potentially useful tool coming out of the study was a “polygenic risk score,” which the researchers developed based on the genes identified. When they tested how accurately the score could predict whether someone would develop RLS within the next 5 years, the model got it right about 90% of the time.
Dr. Winkelmann imagines a day when someone could use such a polygenic risk score to flag the high risk for RLS early enough to take action to try to prevent it. More research is necessary to determine precisely what that action would be.
As for treatments, Dr. Berkowski thinks it’s unlikely that doctors will suddenly begin using existing, glutamate-targeting drugs off-label to treat RLS, as many are prohibitively expensive and wouldn’t be covered by insurance. But he’s optimistic that the study can spawn new research that could ultimately help fill the treatment gap.
Shalini Paruthi, MD, an adjunct professor at Saint Louis University, St. Louis, Missouri, and chair of the Restless Legs Syndrome Foundation’s board of directors, sees another benefit.
“The associations found in this study between RLS and other medical disorders may help patients and their physicians take RLS more seriously,” Dr. Paruthi said, “as treating RLS can lead to multiple other downstream improvements in their health.”
A version of this article appeared on Medscape.com.
For decades, scientists have been trying to unravel the mysteries of restless legs syndrome (RLS), a poorly understood and underdiagnosed neurological disorder causing itching, crawling, and aching sensations in the limbs that can only be relieved with movement.
A sweeping new genetic study, coauthored by an international team of 70 — including the world’s leading RLS experts — marks a significant advance in that pursuit. Published in Nature Genetics, it is the largest genetic study of the disease to date.
“It’s a huge step forward for patients as well as the scientific community,” said lead author Juliane Winkelmann, MD, a neurologist and geneticist with the Technical University of Munich, Munich, Germany, who’s been studying and treating patients with RLS for 30 years. “We believe it will allow us to better predict the likelihood of developing RLS and investigate new ways to prevent and modify it.”
The common condition, affecting about 1 in 10 adults, was first described centuries ago — by English physician Thomas Willis in the late 1600s. And while we know a lot more about it today — it’s familial in about half of all patients and has been linked to iron deficiency, among other conditions — its exact cause remains unknown.
With preferred drugs long prescribed to quell symptoms shown in recent years to actually worsen the disorder over time, doctors and patients are hungry for alternatives to treat or prevent the sleep-sabotaging condition.
“The main treatments that everybody continues to use are actually making people worse,” said Andrew Berkowski, MD, a Michigan-based neurologist and RLS specialist not involved in the study. These drugs — dopamine agonists such as levodopa and pramipexole — can also potentially cause drug dependence, Dr. Berkowski said.
How This Could Lead to New Treatments
In the new study, the group analyzed three genome-wide association studies, collectively including genetic information from 116,647 patients with RLS and more than 1.5 million people without it.
They identified 161 gene regions believed to contribute to RLS, about a dozen of which are already targets for existing drugs for other conditions. Previously, scientists knew of only 22 associated genes.
“It’s useful in that it identifies new genes we haven’t looked at yet and reinforces the science behind some of the older genes,” said Dr. Berkowski. “It’s given us some ideas for different things we should look into more closely.”
Among the top candidates are genes that influence glutamate — a key chemical messenger that helps move signals between nerve cells in the brain.
Several anticonvulsant and antiseizure drugs, including perampanel, lamotrigine, and gabapentin, target glutamate receptors. And at least one small study has shown perampanel prescribed off-label can improve RLS symptoms.
“Compared to starting at the beginning and developing an entirely new chemical entity, we could run clinical trials using these alternatives in RLS patients,” said the study’s first author, Steven Bell, PhD, an epidemiologist with the University of Cambridge, Cambridge, England.
The study also confirmed the MIES1 gene, which is related to dopamine expression and iron homeostasis, as a key genetic contributor to RLS risk. Low levels of iron in the blood have long been thought to trigger RLS.
The Role of Gene-Environment Interactions
Through additional data analysis, the team confirmed that many of the genes associated with RLS play a role in development of the central nervous system.
“This strongly supports the hypothesis that restless legs syndrome is a neurodevelopmental disorder that develops during the embryo stage but doesn’t clinically manifest until later in life,” said Dr. Winkelmann.
About half of people with RLS report some family history of it.
But not all with a genetic predisposition will develop symptoms.
For instance, the study found that while the same gene regions seem to be associated with risk in both men and women, in practice, RLS is twice as common among women. This suggests that something about women’s lives — menstruation, childbirth, metabolism — may switch a preexisting risk into a reality.
“We know that genetic factors play an important role in making people susceptible to the disease,” said Dr. Winkelmann, “but in the end, it is the interaction between genetic and environmental factors that may lead to its manifestation.”
The study also found associations between RLS and depression and suggests that RLS may increase the risk for type 2 diabetes.
Improving RLS Care
A potentially useful tool coming out of the study was a “polygenic risk score,” which the researchers developed based on the genes identified. When they tested how accurately the score could predict whether someone would develop RLS within the next 5 years, the model got it right about 90% of the time.
Dr. Winkelmann imagines a day when someone could use such a polygenic risk score to flag the high risk for RLS early enough to take action to try to prevent it. More research is necessary to determine precisely what that action would be.
As for treatments, Dr. Berkowski thinks it’s unlikely that doctors will suddenly begin using existing, glutamate-targeting drugs off-label to treat RLS, as many are prohibitively expensive and wouldn’t be covered by insurance. But he’s optimistic that the study can spawn new research that could ultimately help fill the treatment gap.
Shalini Paruthi, MD, an adjunct professor at Saint Louis University, St. Louis, Missouri, and chair of the Restless Legs Syndrome Foundation’s board of directors, sees another benefit.
“The associations found in this study between RLS and other medical disorders may help patients and their physicians take RLS more seriously,” Dr. Paruthi said, “as treating RLS can lead to multiple other downstream improvements in their health.”
A version of this article appeared on Medscape.com.
For decades, scientists have been trying to unravel the mysteries of restless legs syndrome (RLS), a poorly understood and underdiagnosed neurological disorder causing itching, crawling, and aching sensations in the limbs that can only be relieved with movement.
A sweeping new genetic study, coauthored by an international team of 70 — including the world’s leading RLS experts — marks a significant advance in that pursuit. Published in Nature Genetics, it is the largest genetic study of the disease to date.
“It’s a huge step forward for patients as well as the scientific community,” said lead author Juliane Winkelmann, MD, a neurologist and geneticist with the Technical University of Munich, Munich, Germany, who’s been studying and treating patients with RLS for 30 years. “We believe it will allow us to better predict the likelihood of developing RLS and investigate new ways to prevent and modify it.”
The common condition, affecting about 1 in 10 adults, was first described centuries ago — by English physician Thomas Willis in the late 1600s. And while we know a lot more about it today — it’s familial in about half of all patients and has been linked to iron deficiency, among other conditions — its exact cause remains unknown.
With preferred drugs long prescribed to quell symptoms shown in recent years to actually worsen the disorder over time, doctors and patients are hungry for alternatives to treat or prevent the sleep-sabotaging condition.
“The main treatments that everybody continues to use are actually making people worse,” said Andrew Berkowski, MD, a Michigan-based neurologist and RLS specialist not involved in the study. These drugs — dopamine agonists such as levodopa and pramipexole — can also potentially cause drug dependence, Dr. Berkowski said.
How This Could Lead to New Treatments
In the new study, the group analyzed three genome-wide association studies, collectively including genetic information from 116,647 patients with RLS and more than 1.5 million people without it.
They identified 161 gene regions believed to contribute to RLS, about a dozen of which are already targets for existing drugs for other conditions. Previously, scientists knew of only 22 associated genes.
“It’s useful in that it identifies new genes we haven’t looked at yet and reinforces the science behind some of the older genes,” said Dr. Berkowski. “It’s given us some ideas for different things we should look into more closely.”
Among the top candidates are genes that influence glutamate — a key chemical messenger that helps move signals between nerve cells in the brain.
Several anticonvulsant and antiseizure drugs, including perampanel, lamotrigine, and gabapentin, target glutamate receptors. And at least one small study has shown perampanel prescribed off-label can improve RLS symptoms.
“Compared to starting at the beginning and developing an entirely new chemical entity, we could run clinical trials using these alternatives in RLS patients,” said the study’s first author, Steven Bell, PhD, an epidemiologist with the University of Cambridge, Cambridge, England.
The study also confirmed the MIES1 gene, which is related to dopamine expression and iron homeostasis, as a key genetic contributor to RLS risk. Low levels of iron in the blood have long been thought to trigger RLS.
The Role of Gene-Environment Interactions
Through additional data analysis, the team confirmed that many of the genes associated with RLS play a role in development of the central nervous system.
“This strongly supports the hypothesis that restless legs syndrome is a neurodevelopmental disorder that develops during the embryo stage but doesn’t clinically manifest until later in life,” said Dr. Winkelmann.
About half of people with RLS report some family history of it.
But not all with a genetic predisposition will develop symptoms.
For instance, the study found that while the same gene regions seem to be associated with risk in both men and women, in practice, RLS is twice as common among women. This suggests that something about women’s lives — menstruation, childbirth, metabolism — may switch a preexisting risk into a reality.
“We know that genetic factors play an important role in making people susceptible to the disease,” said Dr. Winkelmann, “but in the end, it is the interaction between genetic and environmental factors that may lead to its manifestation.”
The study also found associations between RLS and depression and suggests that RLS may increase the risk for type 2 diabetes.
Improving RLS Care
A potentially useful tool coming out of the study was a “polygenic risk score,” which the researchers developed based on the genes identified. When they tested how accurately the score could predict whether someone would develop RLS within the next 5 years, the model got it right about 90% of the time.
Dr. Winkelmann imagines a day when someone could use such a polygenic risk score to flag the high risk for RLS early enough to take action to try to prevent it. More research is necessary to determine precisely what that action would be.
As for treatments, Dr. Berkowski thinks it’s unlikely that doctors will suddenly begin using existing, glutamate-targeting drugs off-label to treat RLS, as many are prohibitively expensive and wouldn’t be covered by insurance. But he’s optimistic that the study can spawn new research that could ultimately help fill the treatment gap.
Shalini Paruthi, MD, an adjunct professor at Saint Louis University, St. Louis, Missouri, and chair of the Restless Legs Syndrome Foundation’s board of directors, sees another benefit.
“The associations found in this study between RLS and other medical disorders may help patients and their physicians take RLS more seriously,” Dr. Paruthi said, “as treating RLS can lead to multiple other downstream improvements in their health.”
A version of this article appeared on Medscape.com.