Breast Cancer ICYMI

Delayed diagnosis of breast cancer: $15M award

A woman in her mid-50s had been seen by a breast surgeon for 16 years for regular mammograms and sonograms. In May 2009, the breast surgeon misinterpreted a mammogram as negative, as did a radiologist who re-read the mammogram weeks later. In December 2010, the patient returned to the breast surgeon with nipple discharge. No further testing was conducted. In October 2011, the patient was found to have Stage IIIA breast cancer involving 4 lymph nodes. She underwent left radical mastectomy, chemotherapy, radiation therapy, and breast reconstruction. At time of trial, the cancer had invaded her vertebrae, was Stage IV, and most likely incurable.

PATIENT'S CLAIM: Although the surgeon admittedly did not possess the qualifications required under the Mammography Quality Standards Act, he interpreted about 5,000 mammograms per year in his office. In this case, he failed to detect a small breast tumor in May 2009. He also failed to perform testing when the patient reported nipple discharge. A more timely diagnosis of breast cancer at Stage I would have provided a 90% chance of long-term survival.

DEFENDANTS' DEFENSE: The defense held the radiologist fully liable because the surgeon was not a qualified interpreter of mammography, therefore relying on the radiologist’s interpretation. The radiologist was legally responsible for the missed diagnosis.

VERDICT: A $15M New York verdict was reached, finding the breast surgeon 75% at fault and the radiologist 25%. The radiologist settled before the trial (the jury was not informed of this). The breast surgeon was responsible for $11.25M. The defense indicated intent to appeal.

Alleged failure to evacuate uterus after cesarean delivery

A 37-year-old woman underwent cesarean delivery (CD) performed by 2 ObGyns. After delivery, she began to hemorrhage and the uterus became atonic. Hysterectomy was performed but the bleeding did not stop. The ObGyns called in 3 other ObGyns. During exploratory laparotomy, the bleeding was halted.

PATIENT'S CLAIM: She and her husband had hoped to have more children but the hysterectomy precluded that. She sued all 5 ObGyns, alleging that the delivering ObGyns failed to properly perform the CD and that each physician failed to properly perform the laparotomy, causing a large scar. The claim was discontinued against the 3 surgical ObGyns; trial addressed the 2 delivering ObGyns.

The patient’s expert ObGyn remarked that the hemorrhage was caused by a small placental remnant that remained in the uterus as a result of inadequate evacuation following delivery. The presence of the remnant was indicated by the uterine atony and should have prompted immediate investigation. The physicians’ notes did not document exploration of the uterus prior to closure.

PHYSICIAN'S DEFENSE: The defense’s expert contended that atony would not be a result of a small remnant of placenta. The patient’s uterus was properly evacuated, the hemorrhage was an unforeseeable complication, and the ObGyns properly addressed the hemorrhage.

VERDICT: A New York defense verdict was returned.

Alleged bowel injury during hysterectomy

Two days after a woman underwent a hysterectomy performed by her ObGyn, she went to the emergency department with increasing pain. Her ObGyn admitted her to the hospital. A general surgeon performed an exploratory laparotomy the next day that revealed an abscess; a 1-cm perforation of the patient’s bowel was surgically repaired. The patient had a difficult recovery. She developed pneumonia and respiratory failure. She underwent multiple repair surgeries for recurrent abscesses and fistulas because the wound was slow to heal.

PATIENT'S CLAIM: The ObGyn’s surgical technique was negligent. He injured the bowel when inserting a trocar and did not identify the injury in a timely manner. The expert witness commented that such an injury can sometimes be a surgical complication, but not in this case: the ObGyn rushed the procedure because he had another patient waiting for CD at another hospital.

PHYSICIAN'S DEFENSE: The ObGyn denied negligence and contended that the trocar used in surgery was too blunt to have caused a perforation. It would have been obvious to the ObGyn during surgery if a perforation had occurred. The perforation developed days after surgery within an abscess.

VERDICT: A Mississippi defense verdict was returned.

These cases were selected by the editors of OBG Management from Medical Malpractice Verdicts, Settlements & Experts, with permission of the editor, Lewis Laska (www.verdictslaska.com). The information available to the editors about the cases presented here is sometimes incomplete. Moreover, the cases may or may not have merit. Nevertheless, these cases represent the types of clinical situations that typically result in litigation and are meant to illustrate nationwide variation in jury verdicts and awards.

Share your thoughts! Send your Letter to the Editor to rbarbieri@mdedge.com. Please include your name and the city and state in which you practice.

Delayed diagnosis of breast cancer: $15M award

A woman in her mid-50s had been seen by a breast surgeon for 16 years for regular mammograms and sonograms. In May 2009, the breast surgeon misinterpreted a mammogram as negative, as did a radiologist who re-read the mammogram weeks later. In December 2010, the patient returned to the breast surgeon with nipple discharge. No further testing was conducted. In October 2011, the patient was found to have Stage IIIA breast cancer involving 4 lymph nodes. She underwent left radical mastectomy, chemotherapy, radiation therapy, and breast reconstruction. At time of trial, the cancer had invaded her vertebrae, was Stage IV, and most likely incurable.

PATIENT'S CLAIM: Although the surgeon admittedly did not possess the qualifications required under the Mammography Quality Standards Act, he interpreted about 5,000 mammograms per year in his office. In this case, he failed to detect a small breast tumor in May 2009. He also failed to perform testing when the patient reported nipple discharge. A more timely diagnosis of breast cancer at Stage I would have provided a 90% chance of long-term survival.

DEFENDANTS' DEFENSE: The defense held the radiologist fully liable because the surgeon was not a qualified interpreter of mammography, therefore relying on the radiologist’s interpretation. The radiologist was legally responsible for the missed diagnosis.

VERDICT: A $15M New York verdict was reached, finding the breast surgeon 75% at fault and the radiologist 25%. The radiologist settled before the trial (the jury was not informed of this). The breast surgeon was responsible for $11.25M. The defense indicated intent to appeal.

Alleged failure to evacuate uterus after cesarean delivery

A 37-year-old woman underwent cesarean delivery (CD) performed by 2 ObGyns. After delivery, she began to hemorrhage and the uterus became atonic. Hysterectomy was performed but the bleeding did not stop. The ObGyns called in 3 other ObGyns. During exploratory laparotomy, the bleeding was halted.

PATIENT'S CLAIM: She and her husband had hoped to have more children but the hysterectomy precluded that. She sued all 5 ObGyns, alleging that the delivering ObGyns failed to properly perform the CD and that each physician failed to properly perform the laparotomy, causing a large scar. The claim was discontinued against the 3 surgical ObGyns; trial addressed the 2 delivering ObGyns.

The patient’s expert ObGyn remarked that the hemorrhage was caused by a small placental remnant that remained in the uterus as a result of inadequate evacuation following delivery. The presence of the remnant was indicated by the uterine atony and should have prompted immediate investigation. The physicians’ notes did not document exploration of the uterus prior to closure.

PHYSICIAN'S DEFENSE: The defense’s expert contended that atony would not be a result of a small remnant of placenta. The patient’s uterus was properly evacuated, the hemorrhage was an unforeseeable complication, and the ObGyns properly addressed the hemorrhage.

VERDICT: A New York defense verdict was returned.

Alleged bowel injury during hysterectomy

Two days after a woman underwent a hysterectomy performed by her ObGyn, she went to the emergency department with increasing pain. Her ObGyn admitted her to the hospital. A general surgeon performed an exploratory laparotomy the next day that revealed an abscess; a 1-cm perforation of the patient’s bowel was surgically repaired. The patient had a difficult recovery. She developed pneumonia and respiratory failure. She underwent multiple repair surgeries for recurrent abscesses and fistulas because the wound was slow to heal.

PATIENT'S CLAIM: The ObGyn’s surgical technique was negligent. He injured the bowel when inserting a trocar and did not identify the injury in a timely manner. The expert witness commented that such an injury can sometimes be a surgical complication, but not in this case: the ObGyn rushed the procedure because he had another patient waiting for CD at another hospital.

PHYSICIAN'S DEFENSE: The ObGyn denied negligence and contended that the trocar used in surgery was too blunt to have caused a perforation. It would have been obvious to the ObGyn during surgery if a perforation had occurred. The perforation developed days after surgery within an abscess.

VERDICT: A Mississippi defense verdict was returned.

These cases were selected by the editors of OBG Management from Medical Malpractice Verdicts, Settlements & Experts, with permission of the editor, Lewis Laska (www.verdictslaska.com). The information available to the editors about the cases presented here is sometimes incomplete. Moreover, the cases may or may not have merit. Nevertheless, these cases represent the types of clinical situations that typically result in litigation and are meant to illustrate nationwide variation in jury verdicts and awards.

Share your thoughts! Send your Letter to the Editor to rbarbieri@mdedge.com. Please include your name and the city and state in which you practice.

Delayed diagnosis of breast cancer: $15M award

A woman in her mid-50s had been seen by a breast surgeon for 16 years for regular mammograms and sonograms. In May 2009, the breast surgeon misinterpreted a mammogram as negative, as did a radiologist who re-read the mammogram weeks later. In December 2010, the patient returned to the breast surgeon with nipple discharge. No further testing was conducted. In October 2011, the patient was found to have Stage IIIA breast cancer involving 4 lymph nodes. She underwent left radical mastectomy, chemotherapy, radiation therapy, and breast reconstruction. At time of trial, the cancer had invaded her vertebrae, was Stage IV, and most likely incurable.

PATIENT'S CLAIM: Although the surgeon admittedly did not possess the qualifications required under the Mammography Quality Standards Act, he interpreted about 5,000 mammograms per year in his office. In this case, he failed to detect a small breast tumor in May 2009. He also failed to perform testing when the patient reported nipple discharge. A more timely diagnosis of breast cancer at Stage I would have provided a 90% chance of long-term survival.

DEFENDANTS' DEFENSE: The defense held the radiologist fully liable because the surgeon was not a qualified interpreter of mammography, therefore relying on the radiologist’s interpretation. The radiologist was legally responsible for the missed diagnosis.

VERDICT: A $15M New York verdict was reached, finding the breast surgeon 75% at fault and the radiologist 25%. The radiologist settled before the trial (the jury was not informed of this). The breast surgeon was responsible for $11.25M. The defense indicated intent to appeal.

Alleged failure to evacuate uterus after cesarean delivery

A 37-year-old woman underwent cesarean delivery (CD) performed by 2 ObGyns. After delivery, she began to hemorrhage and the uterus became atonic. Hysterectomy was performed but the bleeding did not stop. The ObGyns called in 3 other ObGyns. During exploratory laparotomy, the bleeding was halted.

PATIENT'S CLAIM: She and her husband had hoped to have more children but the hysterectomy precluded that. She sued all 5 ObGyns, alleging that the delivering ObGyns failed to properly perform the CD and that each physician failed to properly perform the laparotomy, causing a large scar. The claim was discontinued against the 3 surgical ObGyns; trial addressed the 2 delivering ObGyns.

The patient’s expert ObGyn remarked that the hemorrhage was caused by a small placental remnant that remained in the uterus as a result of inadequate evacuation following delivery. The presence of the remnant was indicated by the uterine atony and should have prompted immediate investigation. The physicians’ notes did not document exploration of the uterus prior to closure.

PHYSICIAN'S DEFENSE: The defense’s expert contended that atony would not be a result of a small remnant of placenta. The patient’s uterus was properly evacuated, the hemorrhage was an unforeseeable complication, and the ObGyns properly addressed the hemorrhage.

VERDICT: A New York defense verdict was returned.

Alleged bowel injury during hysterectomy

Two days after a woman underwent a hysterectomy performed by her ObGyn, she went to the emergency department with increasing pain. Her ObGyn admitted her to the hospital. A general surgeon performed an exploratory laparotomy the next day that revealed an abscess; a 1-cm perforation of the patient’s bowel was surgically repaired. The patient had a difficult recovery. She developed pneumonia and respiratory failure. She underwent multiple repair surgeries for recurrent abscesses and fistulas because the wound was slow to heal.

PATIENT'S CLAIM: The ObGyn’s surgical technique was negligent. He injured the bowel when inserting a trocar and did not identify the injury in a timely manner. The expert witness commented that such an injury can sometimes be a surgical complication, but not in this case: the ObGyn rushed the procedure because he had another patient waiting for CD at another hospital.

PHYSICIAN'S DEFENSE: The ObGyn denied negligence and contended that the trocar used in surgery was too blunt to have caused a perforation. It would have been obvious to the ObGyn during surgery if a perforation had occurred. The perforation developed days after surgery within an abscess.

VERDICT: A Mississippi defense verdict was returned.

These cases were selected by the editors of OBG Management from Medical Malpractice Verdicts, Settlements & Experts, with permission of the editor, Lewis Laska (www.verdictslaska.com). The information available to the editors about the cases presented here is sometimes incomplete. Moreover, the cases may or may not have merit. Nevertheless, these cases represent the types of clinical situations that typically result in litigation and are meant to illustrate nationwide variation in jury verdicts and awards.

Share your thoughts! Send your Letter to the Editor to rbarbieri@mdedge.com. Please include your name and the city and state in which you practice.

Spinal muscular atrophy (SMA) is now among the disorders officially included in the Recommended Uniform Screening Panel (RUSP), which state public health departments use to screen newborns for genetic disorders.

Secretary of the Department of Health and Human Services (HHS) Alex M. Azar II formally added SMA to the panel on July 2 on the recommendation of the Advisory Committee on Heritable Disorders in Newborns and Children.

“Adding SMA to the list will help ensure that babies born with SMA are identified, so that they have the opportunity to benefit from early treatment and intervention,” according to a statement from the Muscular Dystrophy Association about the decision. “This testing can also provide families with a genetic diagnosis—information that often is required to determine whether their child is eligible to participate in clinical trials.”

Adding SMA to the RUSP does not mean that states must screen newborns for the disorder. Each state’s public health apparatus decides independently whether to accept the recommendation and which disorders on the RUSP to screen for. Most states screen for most disorders on the RUSP. Evidence compiled by the advisory committee suggested a wide variation in resources, infrastructure, funding, and time to implementation among states.

Drug Approval Raised Ethical Questions

An estimated one in 11,000 newborns has SMA, a disorder caused by mutations in the survival motor neuron 1 (SMN1) gene. SMA affects motor neurons in the brainstem and spinal cord, thus leading to motor weakness and atrophy. The only treatment for SMA had been palliative care until the FDA approved nusinersen for the disorder in December 2016. The drug’s approval has raised ethical questions.^1–3

After reviewing the evidence at its February 8 meeting, the advisory committee recommended adding SMA screening to the RUSP in a March 8 letter from committee chair Joseph A. Bocchini Jr, MD, Professor and Chair of Pediatrics at Louisiana State University Health in Shreveport.

According to Secretary Azar’s summary in his July 2 letter of acceptance, the evidence review suggested that “early screening and treatment can lead to decreased mortality for individuals with SMA and improved motor milestones.”

“SMA can be detected through newborn screening, and treatment is now available that can not only reduce the risk of death, but decrease the development of neurologic impairment,” he said in an interview. “As with adding any condition to newborn screening, public health laboratories will need to develop strategies to incorporate the screening test. The current FDA-approved treatment, nusinersen, is delivered by lumbar puncture into the spinal fluid. In addition, there are exciting advances in gene therapy leading to new treatment approaches.”

Symptom Onset Distinguishes the Types of SMA

Approximately 95% of SMA cases result from the deletion of exon 7 from both alleles of SMN1. Other, rarer cases are caused by mutations in different genes. Without the SMN protein produced by SMN1, a person gradually loses muscle function.

A similar gene, SMN2, also can produce the SMN protein, but in much lower amounts—typically less than 10% of what a person needs. People can, however, have multiple copies of SMN2, which can produce slightly more SMN protein and slow the disease process.

The five types of SMA are determined according to symptom onset, which directly correlates with disorder severity and prognosis. Approximately 54% of SMA cases are Type I, in which progressive weakness occurs over the first six months of life and results in early death. Only 18% of children with Type I live past age 4, and 68% die by age 2. Type 0 is rarer, but more severe, usually causing fetal loss or early infant death.

Type II represents 18% of SMA cases and causes progressive weakness by age 15 months. Most people with Type II survive to their 30s but later experience respiratory failure and rarely reach their 40s. Individuals with Types III and IV typically have a normal lifespan and only begin to see progressive muscle weakness after age 1 or in adulthood.

Dr. Kemper’s group focused on the three types diagnosed in infancy: Types I, II, and III. “It will be critical to make sure that infants diagnosed with SMA through newborn screening receive follow-up shortly afterward to determine whether they would benefit from nusinersen,” said Dr. Kemper. “More information is needed about the long-term outcomes of those infants who begin treatment following newborn screening, so we not only know about outcomes in later childhood and adolescence, but treatment approaches can be further refined and personalized.”

Long-Term Data on Nusinersen Are Lacking

Nusinersen alters the splicing of precursor messenger RNA in SMN2 so that the mRNA strands are longer, which increases the amount of SMN protein produced. Concerns about the medication, however, have included its cost—$750,000 in the first year and $375,000 every following year for life—and potential adverse events from repeated administration. Nusinersen is injected into the spinal canal four times in the first year and once annually thereafter, and the painful injections require patient immobilization. Potential adverse events include thrombocytopenia and nephrotoxicity, along with potential complications from repeated lumbar punctures over time.²

Other concerns about the drug include its limited evidence base, lack of long-term data, associated costs with administration (eg, travel costs), the potential for patients taking nusinersen to be excluded from future clinical trials on other treatments, and ensuring parents have enough information on the drug’s limitations and potential risks to provide adequate informed consent.²

Yet evidence to date is favorable in children with early onset SMA. Dr. Bocchini wrote in the letter to Secretary Azar that “limited data suggest that treatment effect is greater when the treatment is initiated before symptoms develop and when the individual has more copies of SMN2.”

Dr. Kemper’s group concluded that screening can detect SMA in newborns and that treatment can modify the disease course. “Grey literature suggests those with total disease duration less than or equal to 12 weeks before nusinersen treatment were more likely to have better outcomes than those with longer periods of disease duration.

“Presymptomatic treatment alters the natural history” of the disorder, the group found, although outcome data past age 1 are not yet available. Based on findings from a New York pilot program, they predicted that nationwide newborn screening would avert 33 deaths and 48 cases of children who were dependent on a ventilator among an annual cohort of four million births.

At the time of the evidence review, Massachusetts, Minnesota, Missouri, North Carolina, New York, Utah, and Wisconsin initiated pilot programs or whole-population mandated screening for SMA. Of the three states that reported costs, all reported costs of $1 or less per screen.

The research for the evidence review was funded by a Health Resources and Services Administration grant to Duke University in Durham, North Carolina. No disclosures were provided for evidence review group members.

—Tara Haelle

References

1. King NMP, Bishop CE. New treatments for serious conditions: ethical implications. Gene Ther. 2017;24(9):534-538.

2. Gerrity MS, Prasad V, Obley AJ. Concerns about the approval of nusinersen sodium by the US Food and Drug Administration. JAMA Intern Med. 2018;178(6):743-744.

3. Burgart AM, Magnus D, Tabor HK, et al. Ethical challenges confronted when providing nusinersen treatment for spinal muscular atrophy. JAMA Pediatr. 2018;172(2):188-192.

Spinal muscular atrophy (SMA) is now among the disorders officially included in the Recommended Uniform Screening Panel (RUSP), which state public health departments use to screen newborns for genetic disorders.

Secretary of the Department of Health and Human Services (HHS) Alex M. Azar II formally added SMA to the panel on July 2 on the recommendation of the Advisory Committee on Heritable Disorders in Newborns and Children.

“Adding SMA to the list will help ensure that babies born with SMA are identified, so that they have the opportunity to benefit from early treatment and intervention,” according to a statement from the Muscular Dystrophy Association about the decision. “This testing can also provide families with a genetic diagnosis—information that often is required to determine whether their child is eligible to participate in clinical trials.”

Adding SMA to the RUSP does not mean that states must screen newborns for the disorder. Each state’s public health apparatus decides independently whether to accept the recommendation and which disorders on the RUSP to screen for. Most states screen for most disorders on the RUSP. Evidence compiled by the advisory committee suggested a wide variation in resources, infrastructure, funding, and time to implementation among states.

Drug Approval Raised Ethical Questions

An estimated one in 11,000 newborns has SMA, a disorder caused by mutations in the survival motor neuron 1 (SMN1) gene. SMA affects motor neurons in the brainstem and spinal cord, thus leading to motor weakness and atrophy. The only treatment for SMA had been palliative care until the FDA approved nusinersen for the disorder in December 2016. The drug’s approval has raised ethical questions.^1–3

After reviewing the evidence at its February 8 meeting, the advisory committee recommended adding SMA screening to the RUSP in a March 8 letter from committee chair Joseph A. Bocchini Jr, MD, Professor and Chair of Pediatrics at Louisiana State University Health in Shreveport.

According to Secretary Azar’s summary in his July 2 letter of acceptance, the evidence review suggested that “early screening and treatment can lead to decreased mortality for individuals with SMA and improved motor milestones.”

“SMA can be detected through newborn screening, and treatment is now available that can not only reduce the risk of death, but decrease the development of neurologic impairment,” he said in an interview. “As with adding any condition to newborn screening, public health laboratories will need to develop strategies to incorporate the screening test. The current FDA-approved treatment, nusinersen, is delivered by lumbar puncture into the spinal fluid. In addition, there are exciting advances in gene therapy leading to new treatment approaches.”

Symptom Onset Distinguishes the Types of SMA

Approximately 95% of SMA cases result from the deletion of exon 7 from both alleles of SMN1. Other, rarer cases are caused by mutations in different genes. Without the SMN protein produced by SMN1, a person gradually loses muscle function.

A similar gene, SMN2, also can produce the SMN protein, but in much lower amounts—typically less than 10% of what a person needs. People can, however, have multiple copies of SMN2, which can produce slightly more SMN protein and slow the disease process.

The five types of SMA are determined according to symptom onset, which directly correlates with disorder severity and prognosis. Approximately 54% of SMA cases are Type I, in which progressive weakness occurs over the first six months of life and results in early death. Only 18% of children with Type I live past age 4, and 68% die by age 2. Type 0 is rarer, but more severe, usually causing fetal loss or early infant death.

Type II represents 18% of SMA cases and causes progressive weakness by age 15 months. Most people with Type II survive to their 30s but later experience respiratory failure and rarely reach their 40s. Individuals with Types III and IV typically have a normal lifespan and only begin to see progressive muscle weakness after age 1 or in adulthood.

Dr. Kemper’s group focused on the three types diagnosed in infancy: Types I, II, and III. “It will be critical to make sure that infants diagnosed with SMA through newborn screening receive follow-up shortly afterward to determine whether they would benefit from nusinersen,” said Dr. Kemper. “More information is needed about the long-term outcomes of those infants who begin treatment following newborn screening, so we not only know about outcomes in later childhood and adolescence, but treatment approaches can be further refined and personalized.”

Long-Term Data on Nusinersen Are Lacking

Nusinersen alters the splicing of precursor messenger RNA in SMN2 so that the mRNA strands are longer, which increases the amount of SMN protein produced. Concerns about the medication, however, have included its cost—$750,000 in the first year and $375,000 every following year for life—and potential adverse events from repeated administration. Nusinersen is injected into the spinal canal four times in the first year and once annually thereafter, and the painful injections require patient immobilization. Potential adverse events include thrombocytopenia and nephrotoxicity, along with potential complications from repeated lumbar punctures over time.²

Other concerns about the drug include its limited evidence base, lack of long-term data, associated costs with administration (eg, travel costs), the potential for patients taking nusinersen to be excluded from future clinical trials on other treatments, and ensuring parents have enough information on the drug’s limitations and potential risks to provide adequate informed consent.²

Yet evidence to date is favorable in children with early onset SMA. Dr. Bocchini wrote in the letter to Secretary Azar that “limited data suggest that treatment effect is greater when the treatment is initiated before symptoms develop and when the individual has more copies of SMN2.”

Dr. Kemper’s group concluded that screening can detect SMA in newborns and that treatment can modify the disease course. “Grey literature suggests those with total disease duration less than or equal to 12 weeks before nusinersen treatment were more likely to have better outcomes than those with longer periods of disease duration.

“Presymptomatic treatment alters the natural history” of the disorder, the group found, although outcome data past age 1 are not yet available. Based on findings from a New York pilot program, they predicted that nationwide newborn screening would avert 33 deaths and 48 cases of children who were dependent on a ventilator among an annual cohort of four million births.

At the time of the evidence review, Massachusetts, Minnesota, Missouri, North Carolina, New York, Utah, and Wisconsin initiated pilot programs or whole-population mandated screening for SMA. Of the three states that reported costs, all reported costs of $1 or less per screen.

The research for the evidence review was funded by a Health Resources and Services Administration grant to Duke University in Durham, North Carolina. No disclosures were provided for evidence review group members.

—Tara Haelle

References

1. King NMP, Bishop CE. New treatments for serious conditions: ethical implications. Gene Ther. 2017;24(9):534-538.

2. Gerrity MS, Prasad V, Obley AJ. Concerns about the approval of nusinersen sodium by the US Food and Drug Administration. JAMA Intern Med. 2018;178(6):743-744.

3. Burgart AM, Magnus D, Tabor HK, et al. Ethical challenges confronted when providing nusinersen treatment for spinal muscular atrophy. JAMA Pediatr. 2018;172(2):188-192.

Spinal muscular atrophy (SMA) is now among the disorders officially included in the Recommended Uniform Screening Panel (RUSP), which state public health departments use to screen newborns for genetic disorders.

Secretary of the Department of Health and Human Services (HHS) Alex M. Azar II formally added SMA to the panel on July 2 on the recommendation of the Advisory Committee on Heritable Disorders in Newborns and Children.

“Adding SMA to the list will help ensure that babies born with SMA are identified, so that they have the opportunity to benefit from early treatment and intervention,” according to a statement from the Muscular Dystrophy Association about the decision. “This testing can also provide families with a genetic diagnosis—information that often is required to determine whether their child is eligible to participate in clinical trials.”

Adding SMA to the RUSP does not mean that states must screen newborns for the disorder. Each state’s public health apparatus decides independently whether to accept the recommendation and which disorders on the RUSP to screen for. Most states screen for most disorders on the RUSP. Evidence compiled by the advisory committee suggested a wide variation in resources, infrastructure, funding, and time to implementation among states.

Drug Approval Raised Ethical Questions

An estimated one in 11,000 newborns has SMA, a disorder caused by mutations in the survival motor neuron 1 (SMN1) gene. SMA affects motor neurons in the brainstem and spinal cord, thus leading to motor weakness and atrophy. The only treatment for SMA had been palliative care until the FDA approved nusinersen for the disorder in December 2016. The drug’s approval has raised ethical questions.^1–3

After reviewing the evidence at its February 8 meeting, the advisory committee recommended adding SMA screening to the RUSP in a March 8 letter from committee chair Joseph A. Bocchini Jr, MD, Professor and Chair of Pediatrics at Louisiana State University Health in Shreveport.

According to Secretary Azar’s summary in his July 2 letter of acceptance, the evidence review suggested that “early screening and treatment can lead to decreased mortality for individuals with SMA and improved motor milestones.”

“SMA can be detected through newborn screening, and treatment is now available that can not only reduce the risk of death, but decrease the development of neurologic impairment,” he said in an interview. “As with adding any condition to newborn screening, public health laboratories will need to develop strategies to incorporate the screening test. The current FDA-approved treatment, nusinersen, is delivered by lumbar puncture into the spinal fluid. In addition, there are exciting advances in gene therapy leading to new treatment approaches.”

Symptom Onset Distinguishes the Types of SMA

Approximately 95% of SMA cases result from the deletion of exon 7 from both alleles of SMN1. Other, rarer cases are caused by mutations in different genes. Without the SMN protein produced by SMN1, a person gradually loses muscle function.

A similar gene, SMN2, also can produce the SMN protein, but in much lower amounts—typically less than 10% of what a person needs. People can, however, have multiple copies of SMN2, which can produce slightly more SMN protein and slow the disease process.

The five types of SMA are determined according to symptom onset, which directly correlates with disorder severity and prognosis. Approximately 54% of SMA cases are Type I, in which progressive weakness occurs over the first six months of life and results in early death. Only 18% of children with Type I live past age 4, and 68% die by age 2. Type 0 is rarer, but more severe, usually causing fetal loss or early infant death.

Type II represents 18% of SMA cases and causes progressive weakness by age 15 months. Most people with Type II survive to their 30s but later experience respiratory failure and rarely reach their 40s. Individuals with Types III and IV typically have a normal lifespan and only begin to see progressive muscle weakness after age 1 or in adulthood.

Dr. Kemper’s group focused on the three types diagnosed in infancy: Types I, II, and III. “It will be critical to make sure that infants diagnosed with SMA through newborn screening receive follow-up shortly afterward to determine whether they would benefit from nusinersen,” said Dr. Kemper. “More information is needed about the long-term outcomes of those infants who begin treatment following newborn screening, so we not only know about outcomes in later childhood and adolescence, but treatment approaches can be further refined and personalized.”

Long-Term Data on Nusinersen Are Lacking

Nusinersen alters the splicing of precursor messenger RNA in SMN2 so that the mRNA strands are longer, which increases the amount of SMN protein produced. Concerns about the medication, however, have included its cost—$750,000 in the first year and $375,000 every following year for life—and potential adverse events from repeated administration. Nusinersen is injected into the spinal canal four times in the first year and once annually thereafter, and the painful injections require patient immobilization. Potential adverse events include thrombocytopenia and nephrotoxicity, along with potential complications from repeated lumbar punctures over time.²

Other concerns about the drug include its limited evidence base, lack of long-term data, associated costs with administration (eg, travel costs), the potential for patients taking nusinersen to be excluded from future clinical trials on other treatments, and ensuring parents have enough information on the drug’s limitations and potential risks to provide adequate informed consent.²

Yet evidence to date is favorable in children with early onset SMA. Dr. Bocchini wrote in the letter to Secretary Azar that “limited data suggest that treatment effect is greater when the treatment is initiated before symptoms develop and when the individual has more copies of SMN2.”

Dr. Kemper’s group concluded that screening can detect SMA in newborns and that treatment can modify the disease course. “Grey literature suggests those with total disease duration less than or equal to 12 weeks before nusinersen treatment were more likely to have better outcomes than those with longer periods of disease duration.

“Presymptomatic treatment alters the natural history” of the disorder, the group found, although outcome data past age 1 are not yet available. Based on findings from a New York pilot program, they predicted that nationwide newborn screening would avert 33 deaths and 48 cases of children who were dependent on a ventilator among an annual cohort of four million births.

At the time of the evidence review, Massachusetts, Minnesota, Missouri, North Carolina, New York, Utah, and Wisconsin initiated pilot programs or whole-population mandated screening for SMA. Of the three states that reported costs, all reported costs of $1 or less per screen.

The research for the evidence review was funded by a Health Resources and Services Administration grant to Duke University in Durham, North Carolina. No disclosures were provided for evidence review group members.

—Tara Haelle

References

1. King NMP, Bishop CE. New treatments for serious conditions: ethical implications. Gene Ther. 2017;24(9):534-538.

2. Gerrity MS, Prasad V, Obley AJ. Concerns about the approval of nusinersen sodium by the US Food and Drug Administration. JAMA Intern Med. 2018;178(6):743-744.

3. Burgart AM, Magnus D, Tabor HK, et al. Ethical challenges confronted when providing nusinersen treatment for spinal muscular atrophy. JAMA Pediatr. 2018;172(2):188-192.

Residents of Denmark who seek medical attention for traumatic brain injury (TBI) have an increased risk of suicide, compared with the general Danish population without TBI, according to a study published in the August 14 issue of JAMA. “Additional analyses revealed that the risk of suicide was higher for individuals with severe TBI, numerous medical contacts, and longer hospital stays,” said lead author Trine Madsen, PhD. Individuals were at highest risk in the first six months after discharge, said Dr. Madsen, who is a postdoctoral fellow at the Danish Research Institute for Suicide Prevention in Hellerup.

A history of TBI previously has been associated with higher rates of self-harm, suicide, and death than are found in the general population. However, previous studies have been limited by methodological shortcomings, such as small sample sizes and low numbers of suicide cases with TBI. Dr. Madsen and colleagues conducted a retrospective cohort study using nationwide registers covering 7,418,391 individuals living in Denmark between 1980 and 2014 with 164,265,624 person-years’ follow-up. Of these people, 567,823 (7.6%) had a medical contact for TBI, which included mild TBI (ie, concussion), skull fracture without documented TBI, and severe TBI (ie, head injuries with evidence of structural brain injury).

Of 34,529 individuals who died by suicide, 3,536 (10.2%) had medical contact for TBI, including 2,701 for mild TBI, 174 for skull fracture without documented TBI, and 661 for severe TBI. The absolute suicide rate was 41 per 100,000 person-years among those with TBI versus 20 per 100,000 person-years among those with no diagnosis of TBI. After accounting for relevant covariates such as fractures not involving the skull, psychiatric diagnoses, and deliberate self-harm, the adjusted incidence ratio was 1.90.

This study “provides insights into the underappreciated relationship between TBI and suicide,” said Lee Goldstein, MD, PhD, and Ramon Diaz-Arrastia, MD, PhD, in an accompanying editorial. “The results … point to an important clinical triad—TBI history, recent injury (especially with long hospital stays), and more numerous postinjury medical contacts for TBI—that serves as a red flag for increased suicide risk,” said Dr. Goldstein, who is affiliated with Boston University School of Medicine, and Dr. Diaz-Arrastia, of the University of Pennsylvania’s Perelman School of Medicine in Philadelphia. The results “indicate that increased suicide risk is relevant across all TBI severity levels, including the far more common mild injuries. Clinicians, health care professionals, and mental health practitioners must take notice of this important information.”

—Glenn S. Williams

Suggested Reading

Goldstein L, Diaz-Arrastia R. Traumatic brain injury and risk of suicide. JAMA. 2018;320(6):554-556.

Madsen T, Erlangsen A, Orlovska S, et al. Association between traumatic brain injury and risk of suicide. JAMA. 2018;320(6):580-588.

Residents of Denmark who seek medical attention for traumatic brain injury (TBI) have an increased risk of suicide, compared with the general Danish population without TBI, according to a study published in the August 14 issue of JAMA. “Additional analyses revealed that the risk of suicide was higher for individuals with severe TBI, numerous medical contacts, and longer hospital stays,” said lead author Trine Madsen, PhD. Individuals were at highest risk in the first six months after discharge, said Dr. Madsen, who is a postdoctoral fellow at the Danish Research Institute for Suicide Prevention in Hellerup.

A history of TBI previously has been associated with higher rates of self-harm, suicide, and death than are found in the general population. However, previous studies have been limited by methodological shortcomings, such as small sample sizes and low numbers of suicide cases with TBI. Dr. Madsen and colleagues conducted a retrospective cohort study using nationwide registers covering 7,418,391 individuals living in Denmark between 1980 and 2014 with 164,265,624 person-years’ follow-up. Of these people, 567,823 (7.6%) had a medical contact for TBI, which included mild TBI (ie, concussion), skull fracture without documented TBI, and severe TBI (ie, head injuries with evidence of structural brain injury).

Of 34,529 individuals who died by suicide, 3,536 (10.2%) had medical contact for TBI, including 2,701 for mild TBI, 174 for skull fracture without documented TBI, and 661 for severe TBI. The absolute suicide rate was 41 per 100,000 person-years among those with TBI versus 20 per 100,000 person-years among those with no diagnosis of TBI. After accounting for relevant covariates such as fractures not involving the skull, psychiatric diagnoses, and deliberate self-harm, the adjusted incidence ratio was 1.90.

This study “provides insights into the underappreciated relationship between TBI and suicide,” said Lee Goldstein, MD, PhD, and Ramon Diaz-Arrastia, MD, PhD, in an accompanying editorial. “The results … point to an important clinical triad—TBI history, recent injury (especially with long hospital stays), and more numerous postinjury medical contacts for TBI—that serves as a red flag for increased suicide risk,” said Dr. Goldstein, who is affiliated with Boston University School of Medicine, and Dr. Diaz-Arrastia, of the University of Pennsylvania’s Perelman School of Medicine in Philadelphia. The results “indicate that increased suicide risk is relevant across all TBI severity levels, including the far more common mild injuries. Clinicians, health care professionals, and mental health practitioners must take notice of this important information.”

—Glenn S. Williams

Suggested Reading

Goldstein L, Diaz-Arrastia R. Traumatic brain injury and risk of suicide. JAMA. 2018;320(6):554-556.

Madsen T, Erlangsen A, Orlovska S, et al. Association between traumatic brain injury and risk of suicide. JAMA. 2018;320(6):580-588.

Residents of Denmark who seek medical attention for traumatic brain injury (TBI) have an increased risk of suicide, compared with the general Danish population without TBI, according to a study published in the August 14 issue of JAMA. “Additional analyses revealed that the risk of suicide was higher for individuals with severe TBI, numerous medical contacts, and longer hospital stays,” said lead author Trine Madsen, PhD. Individuals were at highest risk in the first six months after discharge, said Dr. Madsen, who is a postdoctoral fellow at the Danish Research Institute for Suicide Prevention in Hellerup.

A history of TBI previously has been associated with higher rates of self-harm, suicide, and death than are found in the general population. However, previous studies have been limited by methodological shortcomings, such as small sample sizes and low numbers of suicide cases with TBI. Dr. Madsen and colleagues conducted a retrospective cohort study using nationwide registers covering 7,418,391 individuals living in Denmark between 1980 and 2014 with 164,265,624 person-years’ follow-up. Of these people, 567,823 (7.6%) had a medical contact for TBI, which included mild TBI (ie, concussion), skull fracture without documented TBI, and severe TBI (ie, head injuries with evidence of structural brain injury).

Of 34,529 individuals who died by suicide, 3,536 (10.2%) had medical contact for TBI, including 2,701 for mild TBI, 174 for skull fracture without documented TBI, and 661 for severe TBI. The absolute suicide rate was 41 per 100,000 person-years among those with TBI versus 20 per 100,000 person-years among those with no diagnosis of TBI. After accounting for relevant covariates such as fractures not involving the skull, psychiatric diagnoses, and deliberate self-harm, the adjusted incidence ratio was 1.90.

This study “provides insights into the underappreciated relationship between TBI and suicide,” said Lee Goldstein, MD, PhD, and Ramon Diaz-Arrastia, MD, PhD, in an accompanying editorial. “The results … point to an important clinical triad—TBI history, recent injury (especially with long hospital stays), and more numerous postinjury medical contacts for TBI—that serves as a red flag for increased suicide risk,” said Dr. Goldstein, who is affiliated with Boston University School of Medicine, and Dr. Diaz-Arrastia, of the University of Pennsylvania’s Perelman School of Medicine in Philadelphia. The results “indicate that increased suicide risk is relevant across all TBI severity levels, including the far more common mild injuries. Clinicians, health care professionals, and mental health practitioners must take notice of this important information.”

—Glenn S. Williams

Suggested Reading

Goldstein L, Diaz-Arrastia R. Traumatic brain injury and risk of suicide. JAMA. 2018;320(6):554-556.

Madsen T, Erlangsen A, Orlovska S, et al. Association between traumatic brain injury and risk of suicide. JAMA. 2018;320(6):580-588.

LOS ANGELES – Serum neurofilament light chain shows promise as a biomarker for disease severity and response to treatment with autologous bone marrow transplant in patients with multiple sclerosis, according to findings from an analysis of paired samples.

solitude72/iStockphoto

Serum neurofilament light chain (Nf-L) levels were found to be significantly elevated in both the serum and cerebrospinal fluid (CSF) of 23 patients with aggressive multiple sclerosis (MS), compared with samples from 5 controls with noninflammatory neurologic conditions such as chronic fatigue syndrome or migraine. The levels in the patients with MS were significantly reduced following autologous bone marrow transplant (BMT), Simon Thebault, MD, reported in a poster at the annual meeting of the American Academy of Neurology.

Nf-L has been shown to be a biomarker for neuronal damage and to have potential for denoting disease severity and treatment response in MS; for this analysis, samples from patients were collected at baseline and annually for 3 years after transplant. Samples from controls were obtained for comparison.

“Our objective, really, was [to determine if we could] detect a treatment response in neurofilament light chain, and secondly, did the degree of neurofilament light chain being high at baseline predict anything about subsequent disease outcome?” Dr. Thebault, a third-year resident at the University of Ottawa, reported in the poster.

Indeed, a treatment response was detected; baseline levels were high, and levels in both serum and CSF were down significantly (P = .05) at both 1 and 3 years following bone marrow transplant, and they stayed down. “In fact, they were so low, they were not significantly different from [the levels] in noninflammatory controls,” he said, noting that serum and CSF NfL levels were highly correlated (r = .833; P less than .001).

Study subjects were patients with aggressive MS, characterized by early disease onset, rapid progression, frequent relapses, and poor treatment responses. Such patients who have received autologous BMT represent an interesting group for examining treatment responses, he said.

At baseline, these patients presumably have a high burden of tissue injury, which would be representative of high levels of Nf-L; good, prospective data show these patients have no evidence of ongoing inflammatory disease following an intensive regimen that includes chemoablation and reinfusion of autologous stem cells, which is representative of a significant reduction of neurofilament levels, he explained.

Importantly, serum and CSF levels were correlated in this study, he said, noting that most prior work has involved CSF, but “the real clinical utility in neurofilament light chain is probably in the serum, because patients don’t like having lumbar punctures too often.”

With respect to the second question pertaining to disease outcomes, the study did show that patients with baseline Nf-L levels above the median for the group had worse T1 lesion volumes at baseline and after transplant (P = .0021 at 36 months), and also had worsening brain atrophy even after transplant (P = .0389 at 60 months).

The curves appeared to be diverging, suggesting that, in the absence of inflammatory disease activity, patients with high Nf-L levels at baseline continue to have ongoing atrophy at a differential rate, compared with those with low baseline levels, Dr. Thebault said.

Other findings included better Expanded Disability Status Scale outcomes after transplant in patients with lower baseline Nf-L, and a trend toward worsening outcomes among those with higher baseline Nf-L levels, although the study may have been underpowered for this. Additionally, lower baseline Nf-L predicted significantly lower T1 and T2 lesion volume, number of gadolinium-enhancing lesions, and a reduction in brain atrophy, whereas higher baseline Nf-L predicted the opposite, he noted, adding that N-acetylaspartate-to-creatinine ratios also tended to vary inversely with Nf-L levels.

The most important findings of the study are “the sustained reduction in Nf-L levels after BMT, and that higher baseline levels predicted worse MRI outcomes,” Dr. Thebault noted. “Together these data add to a growing body of evidence that suggests that serum Nf-L has a role in monitoring treatment responses and even a predictive value in determining disease severity.”

This study was supported by Quanterix, which provided Nf-L assay kits. Dr. Thebault reported having no disclosures.

sworcester@mdedge.com

SOURCE: Thebault S et al. Neurology. 2018 Apr;90(15 Suppl.):P5.036.

LOS ANGELES – Serum neurofilament light chain shows promise as a biomarker for disease severity and response to treatment with autologous bone marrow transplant in patients with multiple sclerosis, according to findings from an analysis of paired samples.

solitude72/iStockphoto

Serum neurofilament light chain (Nf-L) levels were found to be significantly elevated in both the serum and cerebrospinal fluid (CSF) of 23 patients with aggressive multiple sclerosis (MS), compared with samples from 5 controls with noninflammatory neurologic conditions such as chronic fatigue syndrome or migraine. The levels in the patients with MS were significantly reduced following autologous bone marrow transplant (BMT), Simon Thebault, MD, reported in a poster at the annual meeting of the American Academy of Neurology.

Nf-L has been shown to be a biomarker for neuronal damage and to have potential for denoting disease severity and treatment response in MS; for this analysis, samples from patients were collected at baseline and annually for 3 years after transplant. Samples from controls were obtained for comparison.

“Our objective, really, was [to determine if we could] detect a treatment response in neurofilament light chain, and secondly, did the degree of neurofilament light chain being high at baseline predict anything about subsequent disease outcome?” Dr. Thebault, a third-year resident at the University of Ottawa, reported in the poster.

Indeed, a treatment response was detected; baseline levels were high, and levels in both serum and CSF were down significantly (P = .05) at both 1 and 3 years following bone marrow transplant, and they stayed down. “In fact, they were so low, they were not significantly different from [the levels] in noninflammatory controls,” he said, noting that serum and CSF NfL levels were highly correlated (r = .833; P less than .001).

Study subjects were patients with aggressive MS, characterized by early disease onset, rapid progression, frequent relapses, and poor treatment responses. Such patients who have received autologous BMT represent an interesting group for examining treatment responses, he said.

At baseline, these patients presumably have a high burden of tissue injury, which would be representative of high levels of Nf-L; good, prospective data show these patients have no evidence of ongoing inflammatory disease following an intensive regimen that includes chemoablation and reinfusion of autologous stem cells, which is representative of a significant reduction of neurofilament levels, he explained.

Importantly, serum and CSF levels were correlated in this study, he said, noting that most prior work has involved CSF, but “the real clinical utility in neurofilament light chain is probably in the serum, because patients don’t like having lumbar punctures too often.”

With respect to the second question pertaining to disease outcomes, the study did show that patients with baseline Nf-L levels above the median for the group had worse T1 lesion volumes at baseline and after transplant (P = .0021 at 36 months), and also had worsening brain atrophy even after transplant (P = .0389 at 60 months).

The curves appeared to be diverging, suggesting that, in the absence of inflammatory disease activity, patients with high Nf-L levels at baseline continue to have ongoing atrophy at a differential rate, compared with those with low baseline levels, Dr. Thebault said.

Other findings included better Expanded Disability Status Scale outcomes after transplant in patients with lower baseline Nf-L, and a trend toward worsening outcomes among those with higher baseline Nf-L levels, although the study may have been underpowered for this. Additionally, lower baseline Nf-L predicted significantly lower T1 and T2 lesion volume, number of gadolinium-enhancing lesions, and a reduction in brain atrophy, whereas higher baseline Nf-L predicted the opposite, he noted, adding that N-acetylaspartate-to-creatinine ratios also tended to vary inversely with Nf-L levels.

The most important findings of the study are “the sustained reduction in Nf-L levels after BMT, and that higher baseline levels predicted worse MRI outcomes,” Dr. Thebault noted. “Together these data add to a growing body of evidence that suggests that serum Nf-L has a role in monitoring treatment responses and even a predictive value in determining disease severity.”

This study was supported by Quanterix, which provided Nf-L assay kits. Dr. Thebault reported having no disclosures.

sworcester@mdedge.com

SOURCE: Thebault S et al. Neurology. 2018 Apr;90(15 Suppl.):P5.036.

LOS ANGELES – Serum neurofilament light chain shows promise as a biomarker for disease severity and response to treatment with autologous bone marrow transplant in patients with multiple sclerosis, according to findings from an analysis of paired samples.

solitude72/iStockphoto

Serum neurofilament light chain (Nf-L) levels were found to be significantly elevated in both the serum and cerebrospinal fluid (CSF) of 23 patients with aggressive multiple sclerosis (MS), compared with samples from 5 controls with noninflammatory neurologic conditions such as chronic fatigue syndrome or migraine. The levels in the patients with MS were significantly reduced following autologous bone marrow transplant (BMT), Simon Thebault, MD, reported in a poster at the annual meeting of the American Academy of Neurology.

Nf-L has been shown to be a biomarker for neuronal damage and to have potential for denoting disease severity and treatment response in MS; for this analysis, samples from patients were collected at baseline and annually for 3 years after transplant. Samples from controls were obtained for comparison.

“Our objective, really, was [to determine if we could] detect a treatment response in neurofilament light chain, and secondly, did the degree of neurofilament light chain being high at baseline predict anything about subsequent disease outcome?” Dr. Thebault, a third-year resident at the University of Ottawa, reported in the poster.

Indeed, a treatment response was detected; baseline levels were high, and levels in both serum and CSF were down significantly (P = .05) at both 1 and 3 years following bone marrow transplant, and they stayed down. “In fact, they were so low, they were not significantly different from [the levels] in noninflammatory controls,” he said, noting that serum and CSF NfL levels were highly correlated (r = .833; P less than .001).

Study subjects were patients with aggressive MS, characterized by early disease onset, rapid progression, frequent relapses, and poor treatment responses. Such patients who have received autologous BMT represent an interesting group for examining treatment responses, he said.

At baseline, these patients presumably have a high burden of tissue injury, which would be representative of high levels of Nf-L; good, prospective data show these patients have no evidence of ongoing inflammatory disease following an intensive regimen that includes chemoablation and reinfusion of autologous stem cells, which is representative of a significant reduction of neurofilament levels, he explained.

Importantly, serum and CSF levels were correlated in this study, he said, noting that most prior work has involved CSF, but “the real clinical utility in neurofilament light chain is probably in the serum, because patients don’t like having lumbar punctures too often.”

With respect to the second question pertaining to disease outcomes, the study did show that patients with baseline Nf-L levels above the median for the group had worse T1 lesion volumes at baseline and after transplant (P = .0021 at 36 months), and also had worsening brain atrophy even after transplant (P = .0389 at 60 months).

The curves appeared to be diverging, suggesting that, in the absence of inflammatory disease activity, patients with high Nf-L levels at baseline continue to have ongoing atrophy at a differential rate, compared with those with low baseline levels, Dr. Thebault said.

Other findings included better Expanded Disability Status Scale outcomes after transplant in patients with lower baseline Nf-L, and a trend toward worsening outcomes among those with higher baseline Nf-L levels, although the study may have been underpowered for this. Additionally, lower baseline Nf-L predicted significantly lower T1 and T2 lesion volume, number of gadolinium-enhancing lesions, and a reduction in brain atrophy, whereas higher baseline Nf-L predicted the opposite, he noted, adding that N-acetylaspartate-to-creatinine ratios also tended to vary inversely with Nf-L levels.

The most important findings of the study are “the sustained reduction in Nf-L levels after BMT, and that higher baseline levels predicted worse MRI outcomes,” Dr. Thebault noted. “Together these data add to a growing body of evidence that suggests that serum Nf-L has a role in monitoring treatment responses and even a predictive value in determining disease severity.”

This study was supported by Quanterix, which provided Nf-L assay kits. Dr. Thebault reported having no disclosures.

sworcester@mdedge.com

SOURCE: Thebault S et al. Neurology. 2018 Apr;90(15 Suppl.):P5.036.

About one in eight Nigerian women with breast cancer has an inherited mutation of the BRCA1, BRCA2, PALB2, or TP53 gene.

A new analysis of the Nigerian Breast Cancer Study confirmed that these inherited mutations drive about 12% of the country’s breast cancer cases. The findings could pave the way for the first large-scale national breast cancer gene screening program, wrote Olufunmilayo I. Olopade, MD, and her colleagues. The report is in the Journal of Clinical Oncology.

“We suggest that genomic sequencing to identify women at extremely high risk of breast cancer could be a highly innovative approach to tailored risk management and life-saving interventions,” wrote Dr. Olopade, director of the Center for Clinical Cancer Genetics at the University of Chicago, and her colleagues. “Nigeria now has data to prioritize the integration of genetic testing into its cancer control plan. Women with an extremely high risk of breast cancer because of mutations in these genes can be identified inexpensively and unambiguously and offered interventions to reduce cancer risk.”

And, since about half of the sisters and daughters of affected women will carry the same mutation, such a screening program could reach far beyond every index patient identified, the investigators noted.

“If these women at very high risk can be identified either through their relatives with breast cancer or in the general population, resources can be focused particularly on their behalf. For as-yet unaffected women at high genetic risk, these resources would be intensive surveillance for early detection of breast cancer and, after childbearing is completed, the possibility of preventive salpingo-oophorectomy. Integrated population screening for cancer for all women is the goal, but focused outreach to women at extremely high risk represents an especially efficient use of resources and an attainable evidence-based global health approach.”

The Nigerian Breast Cancer Study enrolled 1,136 women with invasive breast cancer from 1998 to 2014. These were compared with 997 women without cancer, matched from the same communities. Genetic sequencing searched for mutations in both known and breast cancer genes.

Cases and controls were a mean of 47 years old; only 6% of cases reported a family history of breast cancer. Of 577 patients with information on tumor stage, 86% (497) were diagnosed at stage III (241) or IV (256).

Among the cases, 167 (14.7%) carried a mutation in a breast cancer risk gene, compared with 1.8% of controls. BRCA1 was the most common mutation, occurring in 7% of patients; these women were 23 times more likely to develop breast cancer than were those without the gene (odds ratio, 23.4). BRCA2 was the next most common, occurring in 4% of cases and conferring a nearly 11-fold increased risk (OR, 10.76). PALB2 occurred in 11 cases (1%) and no controls, and TP53 in four cases (0.4%).

Women with the BRCA1 mutation were diagnosed at a significantly younger age than were other patients (42.6 vs. 47.9 years), as were carriers of the TP53 mutation (32.8 vs. 47.6 years).

Ten other genes (ATM, BARD1, BRIP1, CHEK1, CHEK2, GEN1, NBN, RAD51C, RAD51D, and XRCC2) carried a mutation in at least one patient each. “When limited to mutations in the four high-risk genes, 11%-12% of cases in this study carried a loss-of-function variant.”

Dr. Olopade had no financial disclosures.

msullivan@mdedge.com

SOURCE: Olopade et al. J Clin Oncol. 2018 Aug 21. doi: 10.1200/JCO.2018.78.3977.

About one in eight Nigerian women with breast cancer has an inherited mutation of the BRCA1, BRCA2, PALB2, or TP53 gene.

A new analysis of the Nigerian Breast Cancer Study confirmed that these inherited mutations drive about 12% of the country’s breast cancer cases. The findings could pave the way for the first large-scale national breast cancer gene screening program, wrote Olufunmilayo I. Olopade, MD, and her colleagues. The report is in the Journal of Clinical Oncology.

“We suggest that genomic sequencing to identify women at extremely high risk of breast cancer could be a highly innovative approach to tailored risk management and life-saving interventions,” wrote Dr. Olopade, director of the Center for Clinical Cancer Genetics at the University of Chicago, and her colleagues. “Nigeria now has data to prioritize the integration of genetic testing into its cancer control plan. Women with an extremely high risk of breast cancer because of mutations in these genes can be identified inexpensively and unambiguously and offered interventions to reduce cancer risk.”

And, since about half of the sisters and daughters of affected women will carry the same mutation, such a screening program could reach far beyond every index patient identified, the investigators noted.

“If these women at very high risk can be identified either through their relatives with breast cancer or in the general population, resources can be focused particularly on their behalf. For as-yet unaffected women at high genetic risk, these resources would be intensive surveillance for early detection of breast cancer and, after childbearing is completed, the possibility of preventive salpingo-oophorectomy. Integrated population screening for cancer for all women is the goal, but focused outreach to women at extremely high risk represents an especially efficient use of resources and an attainable evidence-based global health approach.”

The Nigerian Breast Cancer Study enrolled 1,136 women with invasive breast cancer from 1998 to 2014. These were compared with 997 women without cancer, matched from the same communities. Genetic sequencing searched for mutations in both known and breast cancer genes.

Cases and controls were a mean of 47 years old; only 6% of cases reported a family history of breast cancer. Of 577 patients with information on tumor stage, 86% (497) were diagnosed at stage III (241) or IV (256).

Among the cases, 167 (14.7%) carried a mutation in a breast cancer risk gene, compared with 1.8% of controls. BRCA1 was the most common mutation, occurring in 7% of patients; these women were 23 times more likely to develop breast cancer than were those without the gene (odds ratio, 23.4). BRCA2 was the next most common, occurring in 4% of cases and conferring a nearly 11-fold increased risk (OR, 10.76). PALB2 occurred in 11 cases (1%) and no controls, and TP53 in four cases (0.4%).

Women with the BRCA1 mutation were diagnosed at a significantly younger age than were other patients (42.6 vs. 47.9 years), as were carriers of the TP53 mutation (32.8 vs. 47.6 years).

Ten other genes (ATM, BARD1, BRIP1, CHEK1, CHEK2, GEN1, NBN, RAD51C, RAD51D, and XRCC2) carried a mutation in at least one patient each. “When limited to mutations in the four high-risk genes, 11%-12% of cases in this study carried a loss-of-function variant.”

Dr. Olopade had no financial disclosures.

msullivan@mdedge.com

SOURCE: Olopade et al. J Clin Oncol. 2018 Aug 21. doi: 10.1200/JCO.2018.78.3977.

About one in eight Nigerian women with breast cancer has an inherited mutation of the BRCA1, BRCA2, PALB2, or TP53 gene.

A new analysis of the Nigerian Breast Cancer Study confirmed that these inherited mutations drive about 12% of the country’s breast cancer cases. The findings could pave the way for the first large-scale national breast cancer gene screening program, wrote Olufunmilayo I. Olopade, MD, and her colleagues. The report is in the Journal of Clinical Oncology.

“We suggest that genomic sequencing to identify women at extremely high risk of breast cancer could be a highly innovative approach to tailored risk management and life-saving interventions,” wrote Dr. Olopade, director of the Center for Clinical Cancer Genetics at the University of Chicago, and her colleagues. “Nigeria now has data to prioritize the integration of genetic testing into its cancer control plan. Women with an extremely high risk of breast cancer because of mutations in these genes can be identified inexpensively and unambiguously and offered interventions to reduce cancer risk.”

And, since about half of the sisters and daughters of affected women will carry the same mutation, such a screening program could reach far beyond every index patient identified, the investigators noted.

“If these women at very high risk can be identified either through their relatives with breast cancer or in the general population, resources can be focused particularly on their behalf. For as-yet unaffected women at high genetic risk, these resources would be intensive surveillance for early detection of breast cancer and, after childbearing is completed, the possibility of preventive salpingo-oophorectomy. Integrated population screening for cancer for all women is the goal, but focused outreach to women at extremely high risk represents an especially efficient use of resources and an attainable evidence-based global health approach.”

The Nigerian Breast Cancer Study enrolled 1,136 women with invasive breast cancer from 1998 to 2014. These were compared with 997 women without cancer, matched from the same communities. Genetic sequencing searched for mutations in both known and breast cancer genes.

Cases and controls were a mean of 47 years old; only 6% of cases reported a family history of breast cancer. Of 577 patients with information on tumor stage, 86% (497) were diagnosed at stage III (241) or IV (256).

Among the cases, 167 (14.7%) carried a mutation in a breast cancer risk gene, compared with 1.8% of controls. BRCA1 was the most common mutation, occurring in 7% of patients; these women were 23 times more likely to develop breast cancer than were those without the gene (odds ratio, 23.4). BRCA2 was the next most common, occurring in 4% of cases and conferring a nearly 11-fold increased risk (OR, 10.76). PALB2 occurred in 11 cases (1%) and no controls, and TP53 in four cases (0.4%).

Women with the BRCA1 mutation were diagnosed at a significantly younger age than were other patients (42.6 vs. 47.9 years), as were carriers of the TP53 mutation (32.8 vs. 47.6 years).

Ten other genes (ATM, BARD1, BRIP1, CHEK1, CHEK2, GEN1, NBN, RAD51C, RAD51D, and XRCC2) carried a mutation in at least one patient each. “When limited to mutations in the four high-risk genes, 11%-12% of cases in this study carried a loss-of-function variant.”

Dr. Olopade had no financial disclosures.

msullivan@mdedge.com

SOURCE: Olopade et al. J Clin Oncol. 2018 Aug 21. doi: 10.1200/JCO.2018.78.3977.

The small-molecule tyrosine kinase inhibitor neratinib is now approved for the extended adjuvant treatment of patients with early-stage HER2 [human epidermal growth factor receptor]-positive breast cancer following postoperative trastuzumab. Trastuzumab is a HER2-targeted monoclonal antibody that has become standard of care in combination with chemotherapy for the treatment of this patient population in which it significantly improves survival. However, disease recurrence will occur in about a quarter of trastuzumab-treated patients owing to the development of resistance.

Neratinib may help overcome trastuzumab resistance thanks to its potent inhibition of the downstream phosphorylation of HER2 and other members of the HER family. Its approval was based on the phase 3 ExteNET trial, in which extended adjuvant treatment with neratinib was compared with placebo among 2,840 patients who remained disease free after 1 year of adjuvant trastuzumab.¹

The ExteNET trial was performed at 495 centers in Europe, Asia, Australia, New Zealand, and South America. Patients aged 18 years or older (≥20 years in Japan), with stage 1-3 HER2-positive breast cancer, who completed neoadjuvant and adjuvant trastuzumab therapy up to 1 year before randomization were eligible. Patients also had an Eastern Cooperative Oncology Group Performance Status of 0 or 1 (range, 0-5; 0, fully active, and 5, dead), normal organ function, and a left ventricular ejection fraction within normal institutional range. Patients with clinically significant cardiac, gastrointesintal or psychiatric comorbidities and those who were not able to swallow oral medication were excluded from the study.

Patients randomly received oral neratinib 240 mg per day or matching placebo, and randomization was stratified according to HR status (positive or negative), nodal status (0, 1-3, or ≥4) and trastuzumab-adjuvant regimen (sequentially or concurrently with chemotherapy).

The primary outcome was invasive disease-free survival (iDFS). The 2-year iDFS rate was 93.9% for neratinib, compared with 91.6% for placebo (hazard ratio [HR], 0.66; P < .008). Recently, a 5-year analysis of the ExteNET trial showed that after a median follow-up of 5.2 years, the iDFS rates were 90.2% vs 87.7% (HR, 0.73; P = .0083).²

Adverse events

The most common adverse event (AE) was diarrhea, in 95% of patients, 40% of whom had grade 3 diarrhea, leading to dose reduction in 26% of patients and discontinuation in 16.8% of patients. Serious AEs occurred in 7% of patients in the neratinib and 6% of those in the placebo arms. In the 5-year analysis, there was no evidence of increased risk of long-term toxicity or adverse consequences of neratinib-associated diarrhea. Furthermore, the ongoing, open-label phase 2 CONTROL trial suggests that the occurrence and severity of neratinib-associated diarrhea can be effectively controlled with antidiarrheal prophylaxis, with drugs such as loperamide.³

At the January 2017 cut-off, 137 patients treated with neratinib (240 mg/day) for 1 year had also received treatment with loperamide monotherapy, 64 patients had received loperamide and budesonide, and 10 patients had received loperamide and colestipol. The safety data from the loperamide monotherapy arm were compared with the safety data from the ExteNET trial, which was based in a similar population of patients who did not receive antidiarrheal prophylaxis. The incidence of all-grade diarrhea was 77% vs 95%, respectively, for those who received antidiarrheal prophylaxis in the CONTROL trial compared with those in the ExteNET trial who did not, and the repective rates of grade 3 diarrhea were 31% and 40%. The rate of dose reductions and holds owing to diarrhea were also lower among those who received antidiarrheal prophylaxis, but the rate of discontinuation due to diarrhea was higher in the loperamide-treated cohort.
 

Warnings and precautions

Neratinib is marketed as Nerlynx by Puma Biotechnology Inc. The prescribing information describes warnings and precautions relating to diarrhea, hepatotoxicity, and embryofetal toxicity. Patients should be monitored for diarrhea and treated with antidiarrheals as needed. Severe diarrhea with dehydration should be treated with fluids and electrolytes as needed, treatment should be interrupted and resumed at a reduced dose. For grade 3/4 diarrhea or diarrhea with complicating features (eg, dehydration, fever, neutropenia), stool cultures should be performed to rule out infectious causes.

Total bilirubin, aspartate and alanine aminotransferase, and alkaline phosphatase levels should be measured before starting treatment, every 3 months during treatment, or as clinically indicated. Neratinib can cause fetal harm, so pregnant women should be advised of the risk to the fetus and patients of reproductive potential should be counseled on the need for effective contraception during treatment and for at least 1 month after the last dose.⁴

The small-molecule tyrosine kinase inhibitor neratinib is now approved for the extended adjuvant treatment of patients with early-stage HER2 [human epidermal growth factor receptor]-positive breast cancer following postoperative trastuzumab. Trastuzumab is a HER2-targeted monoclonal antibody that has become standard of care in combination with chemotherapy for the treatment of this patient population in which it significantly improves survival. However, disease recurrence will occur in about a quarter of trastuzumab-treated patients owing to the development of resistance.

Neratinib may help overcome trastuzumab resistance thanks to its potent inhibition of the downstream phosphorylation of HER2 and other members of the HER family. Its approval was based on the phase 3 ExteNET trial, in which extended adjuvant treatment with neratinib was compared with placebo among 2,840 patients who remained disease free after 1 year of adjuvant trastuzumab.¹

The ExteNET trial was performed at 495 centers in Europe, Asia, Australia, New Zealand, and South America. Patients aged 18 years or older (≥20 years in Japan), with stage 1-3 HER2-positive breast cancer, who completed neoadjuvant and adjuvant trastuzumab therapy up to 1 year before randomization were eligible. Patients also had an Eastern Cooperative Oncology Group Performance Status of 0 or 1 (range, 0-5; 0, fully active, and 5, dead), normal organ function, and a left ventricular ejection fraction within normal institutional range. Patients with clinically significant cardiac, gastrointesintal or psychiatric comorbidities and those who were not able to swallow oral medication were excluded from the study.

Patients randomly received oral neratinib 240 mg per day or matching placebo, and randomization was stratified according to HR status (positive or negative), nodal status (0, 1-3, or ≥4) and trastuzumab-adjuvant regimen (sequentially or concurrently with chemotherapy).

The primary outcome was invasive disease-free survival (iDFS). The 2-year iDFS rate was 93.9% for neratinib, compared with 91.6% for placebo (hazard ratio [HR], 0.66; P < .008). Recently, a 5-year analysis of the ExteNET trial showed that after a median follow-up of 5.2 years, the iDFS rates were 90.2% vs 87.7% (HR, 0.73; P = .0083).²

Adverse events

The most common adverse event (AE) was diarrhea, in 95% of patients, 40% of whom had grade 3 diarrhea, leading to dose reduction in 26% of patients and discontinuation in 16.8% of patients. Serious AEs occurred in 7% of patients in the neratinib and 6% of those in the placebo arms. In the 5-year analysis, there was no evidence of increased risk of long-term toxicity or adverse consequences of neratinib-associated diarrhea. Furthermore, the ongoing, open-label phase 2 CONTROL trial suggests that the occurrence and severity of neratinib-associated diarrhea can be effectively controlled with antidiarrheal prophylaxis, with drugs such as loperamide.³

At the January 2017 cut-off, 137 patients treated with neratinib (240 mg/day) for 1 year had also received treatment with loperamide monotherapy, 64 patients had received loperamide and budesonide, and 10 patients had received loperamide and colestipol. The safety data from the loperamide monotherapy arm were compared with the safety data from the ExteNET trial, which was based in a similar population of patients who did not receive antidiarrheal prophylaxis. The incidence of all-grade diarrhea was 77% vs 95%, respectively, for those who received antidiarrheal prophylaxis in the CONTROL trial compared with those in the ExteNET trial who did not, and the repective rates of grade 3 diarrhea were 31% and 40%. The rate of dose reductions and holds owing to diarrhea were also lower among those who received antidiarrheal prophylaxis, but the rate of discontinuation due to diarrhea was higher in the loperamide-treated cohort.
 

Warnings and precautions

Neratinib is marketed as Nerlynx by Puma Biotechnology Inc. The prescribing information describes warnings and precautions relating to diarrhea, hepatotoxicity, and embryofetal toxicity. Patients should be monitored for diarrhea and treated with antidiarrheals as needed. Severe diarrhea with dehydration should be treated with fluids and electrolytes as needed, treatment should be interrupted and resumed at a reduced dose. For grade 3/4 diarrhea or diarrhea with complicating features (eg, dehydration, fever, neutropenia), stool cultures should be performed to rule out infectious causes.

Total bilirubin, aspartate and alanine aminotransferase, and alkaline phosphatase levels should be measured before starting treatment, every 3 months during treatment, or as clinically indicated. Neratinib can cause fetal harm, so pregnant women should be advised of the risk to the fetus and patients of reproductive potential should be counseled on the need for effective contraception during treatment and for at least 1 month after the last dose.⁴

The small-molecule tyrosine kinase inhibitor neratinib is now approved for the extended adjuvant treatment of patients with early-stage HER2 [human epidermal growth factor receptor]-positive breast cancer following postoperative trastuzumab. Trastuzumab is a HER2-targeted monoclonal antibody that has become standard of care in combination with chemotherapy for the treatment of this patient population in which it significantly improves survival. However, disease recurrence will occur in about a quarter of trastuzumab-treated patients owing to the development of resistance.

Neratinib may help overcome trastuzumab resistance thanks to its potent inhibition of the downstream phosphorylation of HER2 and other members of the HER family. Its approval was based on the phase 3 ExteNET trial, in which extended adjuvant treatment with neratinib was compared with placebo among 2,840 patients who remained disease free after 1 year of adjuvant trastuzumab.¹

The ExteNET trial was performed at 495 centers in Europe, Asia, Australia, New Zealand, and South America. Patients aged 18 years or older (≥20 years in Japan), with stage 1-3 HER2-positive breast cancer, who completed neoadjuvant and adjuvant trastuzumab therapy up to 1 year before randomization were eligible. Patients also had an Eastern Cooperative Oncology Group Performance Status of 0 or 1 (range, 0-5; 0, fully active, and 5, dead), normal organ function, and a left ventricular ejection fraction within normal institutional range. Patients with clinically significant cardiac, gastrointesintal or psychiatric comorbidities and those who were not able to swallow oral medication were excluded from the study.

Patients randomly received oral neratinib 240 mg per day or matching placebo, and randomization was stratified according to HR status (positive or negative), nodal status (0, 1-3, or ≥4) and trastuzumab-adjuvant regimen (sequentially or concurrently with chemotherapy).

The primary outcome was invasive disease-free survival (iDFS). The 2-year iDFS rate was 93.9% for neratinib, compared with 91.6% for placebo (hazard ratio [HR], 0.66; P < .008). Recently, a 5-year analysis of the ExteNET trial showed that after a median follow-up of 5.2 years, the iDFS rates were 90.2% vs 87.7% (HR, 0.73; P = .0083).²

Adverse events

The most common adverse event (AE) was diarrhea, in 95% of patients, 40% of whom had grade 3 diarrhea, leading to dose reduction in 26% of patients and discontinuation in 16.8% of patients. Serious AEs occurred in 7% of patients in the neratinib and 6% of those in the placebo arms. In the 5-year analysis, there was no evidence of increased risk of long-term toxicity or adverse consequences of neratinib-associated diarrhea. Furthermore, the ongoing, open-label phase 2 CONTROL trial suggests that the occurrence and severity of neratinib-associated diarrhea can be effectively controlled with antidiarrheal prophylaxis, with drugs such as loperamide.³

At the January 2017 cut-off, 137 patients treated with neratinib (240 mg/day) for 1 year had also received treatment with loperamide monotherapy, 64 patients had received loperamide and budesonide, and 10 patients had received loperamide and colestipol. The safety data from the loperamide monotherapy arm were compared with the safety data from the ExteNET trial, which was based in a similar population of patients who did not receive antidiarrheal prophylaxis. The incidence of all-grade diarrhea was 77% vs 95%, respectively, for those who received antidiarrheal prophylaxis in the CONTROL trial compared with those in the ExteNET trial who did not, and the repective rates of grade 3 diarrhea were 31% and 40%. The rate of dose reductions and holds owing to diarrhea were also lower among those who received antidiarrheal prophylaxis, but the rate of discontinuation due to diarrhea was higher in the loperamide-treated cohort.
 

Warnings and precautions

Neratinib is marketed as Nerlynx by Puma Biotechnology Inc. The prescribing information describes warnings and precautions relating to diarrhea, hepatotoxicity, and embryofetal toxicity. Patients should be monitored for diarrhea and treated with antidiarrheals as needed. Severe diarrhea with dehydration should be treated with fluids and electrolytes as needed, treatment should be interrupted and resumed at a reduced dose. For grade 3/4 diarrhea or diarrhea with complicating features (eg, dehydration, fever, neutropenia), stool cultures should be performed to rule out infectious causes.

Total bilirubin, aspartate and alanine aminotransferase, and alkaline phosphatase levels should be measured before starting treatment, every 3 months during treatment, or as clinically indicated. Neratinib can cause fetal harm, so pregnant women should be advised of the risk to the fetus and patients of reproductive potential should be counseled on the need for effective contraception during treatment and for at least 1 month after the last dose.⁴

A new subtype of multiple sclerosis called myelocortical multiple sclerosis is characterized by demyelination only in the spinal cord and cerebral cortex and not in the cerebral white matter.

Copyright (2018), with permission from Elsevier

SOURCE: Trapp B et al. Lancet Neurol. 2018 Aug 21. doi: 10.1016/ S1474-4422(18)30245-X.

A new subtype of multiple sclerosis called myelocortical multiple sclerosis is characterized by demyelination only in the spinal cord and cerebral cortex and not in the cerebral white matter.

Copyright (2018), with permission from Elsevier

SOURCE: Trapp B et al. Lancet Neurol. 2018 Aug 21. doi: 10.1016/ S1474-4422(18)30245-X.

A new subtype of multiple sclerosis called myelocortical multiple sclerosis is characterized by demyelination only in the spinal cord and cerebral cortex and not in the cerebral white matter.

Copyright (2018), with permission from Elsevier

SOURCE: Trapp B et al. Lancet Neurol. 2018 Aug 21. doi: 10.1016/ S1474-4422(18)30245-X.

The relationship between the immune system and tumors is complex and dynamic, and for immunotherapy to reach its full potential it will likely need to attack on multiple fronts. Here, we discuss some of the latest and most promising developments in the immuno-oncology field designed to build on the successes and address limitations.

The anti-tumor immune response

Cancer is a disease of genomic instability, whereby genetic alterations ranging from a single nucleotide to the whole chromosome level frequently occur. Although cancers derive from a patient’s own tissues, these genetic differences can mark the cancer cell as non-self, triggering an immune response to eliminate these cells.

The first hints of this anti-tumor immunity date back more than a century and a half and sparked the concept of mobilizing the immune system to treat patients.^1-3 Although early pioneers achieved little progress in this regard, their efforts provided invaluable insights into the complex and dynamic relationship between a tumor and the immune system that are now translating into real clinical successes.

We now understand that the immune system has a dual role in both restraining and promoting cancer development and have translated this understanding into the theory of cancer immunoediting. Immunoediting has three stages: elimination, wherein the tumor is seemingly destroyed by the innate and adaptive immune response; equilibrium, in which cancer cells that were able to escape elimination are selected for growth; and escape, whereby these resistant cancer cells overwhelm the immune system and develop into a symptomatic lesion.^4,5

Immuno-oncologists have also described the cancer immunity cycle to capture the steps that are required for an effective anti-tumor immune response and defects in this cycle form the basis of the most common mechanisms used by cancer cells to subvert the anti-tumor immune response. Much like the cancer hallmarks did for molecularly targeted cancer drugs, the cancer immunity cycle serves as the intellectual framework for cancer immunotherapy.^6,7

Exploiting nature’s weapon of mass destruction

Initially, attempts at immunotherapy focused on boosting the immune response using adjuvants and cytokines. The characterization of subtle differences between tumor cells and normal cells led to the development of vaccines and cell-based therapies that exploited these tumor-associated antigens (TAAs).^1-6

Despite the approval of a therapeutic vaccine, sipuleucel-T, in 2010 for the treatment of metastatic prostate cancer, in general the success of vaccines has been limited. Marketing authorization for sipuleucel-T was recently withdrawn in Europe, and although it is still available in the United States, it is not widely used because of issues with production and administration. Other vaccines, such as GVAX, which looked particularly promising in early-stage clinical trials, failed to show clinical efficacy in subsequent testing.^8,9

Cell-based therapies, such as adoptive cellular therapy (ACT), in which immune cells are removed from the host, primed to attack cancer cells, and then reinfused back into the patient, have focused on T cells because they are the major effectors of the adaptive immune response. Clinical success with the most common approach, tumor-infiltrating lymphocyte (TIL) therapy, has so far been limited to only one type of cancer – metastatic melanoma – but ACT may be inching closer to the mainstream with the development of techniques that allow genetic manipulation of the T cells before they are infused back into the patient.

Two key techniques have been developed (Figure 1). T-cell receptor (TCR) therapy involves genetically modifying the receptor on the surface of T cells that is responsible for recognizing antigens bound to major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells (APCs). The TCR can be altered to recognize a specific TAA or modified to improve its antigen recognition and binding capabilities. This type of therapy is limited by the fact that the TCRs need to be genetically matched to the patient’s immune type.

Releasing the brakes

To ensure that it is only activated at the appropriate time and not in response to the antigens expressed on the surface of the host’s own tissues or harmless materials, the immune system has developed numerous mechanisms for immunological tolerance. Cancer cells are able to exploit these mechanisms to allow them to evade the anti-tumor immune response. One of the main ways in which they do this is by manipulating the signaling pathways involved in T-cell activation, which play a vital role in tolerance.¹²

To become fully activated, T cells require a primary signal generated by an interaction between the TCR and the antigen-MHC complex on the surface of an APC, followed by secondary costimulatory signals generated by a range of different receptors present on the T-cell surface binding to their ligands on the APC.

If the second signal is inhibitory rather than stimulatory, then the T cell is deactivated instead of becoming activated. Two key coinhibitory receptors are programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) and tumor cells are able to overcome the anti-tumor immune response in part by expressing the ligands that bind these receptors to dampen the activity of tumor-infiltrating T cells and induce tolerance.¹³

The development of inhibitors of CTLA-4 and PD-1 and their respective ligands has driven some of the most dramatic successes with cancer immunotherapy, particularly with PD-1-targeting drugs which have fewer side effects. Targeting of this pathway has resulted in durable responses, revolutionizing the treatment of metastatic melanoma, with recently published long-term survival data for pembrolizumab showing that 40% of patients were alive 3 years after initiating treatment and, in a separate study, 34% of nivolumab-treated patients were still alive after 5 years.^14,15 More recently, PD-1 inhibitors have been slowly expanding into a range of other cancer types and 4 immune checkpoint inhibitors are now approved by the United States Food and Drug Administration (FDA): ipilimumab (Yervoy), nivolumab (Opdivo), pembrolizumab (Keytruda) and atezolizumab (Tecentriq).

Six years on from the first approval in this drug class and an extensive network of coinhibitory receptors has been uncovered – so-called immune checkpoints – many of which are now also serving as therapeutic targets (Table, Figure 2).¹⁶ Lymphocyte activation gene 3 (LAG-3) is a member of the immunoglobulin superfamily of receptors that is expressed on a number of different types of immune cell. In addition to negatively regulating cytotoxic T-cell activation like PD-1 and CTLA-4, it is also thought to regulate the immunosuppressive functions of regulatory T cells and the maturation and activation of dendritic cells. T-cell immunoglobulin and mucin domain-containing 3 (TIM-3) is found on the surface of helper and cytotoxic T cells and regulates T-cell inhibition as well as macrophage activation. Inhibitors of both proteins have been developed that are being evaluated in phase 1 or 2 clinical trials in a variety of tumor types.17

Indeed, although T cells have commanded the most attention, there is growing appreciation of the potential for targeting other types of immune cell that play a role in the anti-tumor immune response or in fostering an immunosuppressive microenvironment. NK cells have been a particular focus, since they represent the body’s first line of immune defense and they appear to have analogous inhibitory and activating receptors expressed on their surface that regulate their cytotoxic activity.

The best-defined NK cell receptors are the killer cell immunoglobulin-like receptors (KIRs) that bind to the MHC class I proteins found on the surface of all cells that distinguish them as ‘self’ or ‘non-self’. KIRs can be either activating or inhibitory, depending upon their structure and the ligands to which they bind.¹⁹ To date, 2 antibodies targeting inhibitory KIRs have been developed. Though there has been some disappointment with these drugs, most recently a phase 2 trial of lirilumab in elderly patients with acute myeloid leukemia, which missed its primary endpoint, they continue to be evaluated in clinical trials.²⁰

The inhibitory immune checkpoint field has also expanded to include molecules that regulate T-cell activity in other ways. Most prominently, this includes enzymes like indoleamine-2,3 dioxygenase (IDO), which is involved in the metabolism of the essential amino acid tryptophan. IDO-induced depletion of tryptophan and generation of tryptophan metabolites is toxic to cytotoxic T cells, and IDO is also thought to directly activate regulatory T cells, thus the net effect of IDO is immunosuppression. Two IDO inhibitors are currently being developed.²¹

Stepping on the gas

Despite their unprecedented success, immune checkpoint inhibitors are not effective in all patients or in all tumor types. Their efficacy is limited in large part by the requirement for a pre-existing anti-tumor immune response. If there are no T cells within the tumor microenvironment then releasing the brakes on the immune system won’t help.

More recently, researchers have returned to the idea of stimulating an anti-tumor immune response, this time by targeting the other side of the immune checkpoint coin, the costimulatory molecules. These drugs could prove more effective as they aren’t reliant on a pre-existing anti-tumor immune response. A number of agonist antibodies designed to target these receptors have now been developed and are undergoing clinical evaluation.²²

Furthest along in development are those targeting OX40, a costimulatory molecule that is upregulated on the surface of T cells once they have been fully activated by the TCR signal and an initial costimulatory signal. OX40 is thought to be involved in a more long-term immune response and in the formation of a memory response. A mouse monoclonal antibody had a potent immune-stimulating effect accompanied by the regression of at least 1 metastatic lesion in 30% of patients treated in a phase 1 clinical trial, but was limited by the generation of anti-mouse antibodies. 7 OX40 agonists are now in clinical development, 6 fully human monoclonal antibodies and 1 OX40 ligand-Fc fusion protein, MEDI-6383.²³

Combinations are key

Many researchers are now reaching the conclusion that combination therapy is likely to be key in expanding the scope of immunotherapy into currently unresponsive patient populations. Investigating rational combinations is already becoming a burgeoning area of the immuno-oncology field, with a variety of different strategies being tested.

Now the question becomes what are the optimal combinations and the timing and sequencing of combination therapy is likely to be a paramount consideration. Developing combinations that have distinct mechanisms of action or target multiple steps in the cancer immunity cycle offers the greatest potential for therapeutic synergy since this is most likely to address potential mechanisms of resistance by blocking other paths to immune evasion for cancer cells (Figure 3).

Given the expanding network of immune-checkpoint inhibitors and agonists, the focal point of combination therapy has been combining immune checkpoint-targeting drugs with different mechanisms of action, including those that would simultaneously release the brakes and step on the gas pedal. The vast majority of ongoing clinical trials of approved checkpoint inhibitors and the drugs in development listed in the table are combination trials.

These efforts yielded the first FDA-approved combination immunotherapy regimen in 2015; nivolumab and ipilimumab for the treatment of metastatic melanoma. Approval was based on the demonstration of improved ORR, prolonged response duration, and improved progression-free survival among 142 patients treated with the combination, compared to either drug alone.²⁴

The results of a phase 1/2 trial evaluating the combination of a 4-1BB receptor agonist urelumab with nivolumab in hematologic malignancies and solid tumors found the combination to be safe and particularly effective in patients with advanced/metastatic melanoma, with an ORR of 50%.²⁵ Nivolumab was also combined with the CD27 agonist varlilumab in a phase 1/2 clinical trial of patients with solid tumors, for which data was also recently released. Among 46 patients enrolled, primarily those with colorectal and ovarian cancer the combination had an acceptable safety profile and favorable changes in intratumoral immune biomarkers were observed. The phase 2 portion of the trial is ongoing.²⁶

Meanwhile, Incyte’s IDO inhibitor epacadostat has recently been making waves in combination with pembrolizumab in patients with advanced solid tumors. It demonstrated particularly promising clinical activity in patients with metastatic melanoma, with an overall response rate (ORR) of 57%, including 2 complete responses (CRs), prompting initiation of a phase 3 trial of this combination (NCT02752074).²⁷

The relationship between the immune system and tumors is complex and dynamic, and for immunotherapy to reach its full potential it will likely need to attack on multiple fronts. Here, we discuss some of the latest and most promising developments in the immuno-oncology field designed to build on the successes and address limitations.

The anti-tumor immune response

Cancer is a disease of genomic instability, whereby genetic alterations ranging from a single nucleotide to the whole chromosome level frequently occur. Although cancers derive from a patient’s own tissues, these genetic differences can mark the cancer cell as non-self, triggering an immune response to eliminate these cells.

The first hints of this anti-tumor immunity date back more than a century and a half and sparked the concept of mobilizing the immune system to treat patients.^1-3 Although early pioneers achieved little progress in this regard, their efforts provided invaluable insights into the complex and dynamic relationship between a tumor and the immune system that are now translating into real clinical successes.

We now understand that the immune system has a dual role in both restraining and promoting cancer development and have translated this understanding into the theory of cancer immunoediting. Immunoediting has three stages: elimination, wherein the tumor is seemingly destroyed by the innate and adaptive immune response; equilibrium, in which cancer cells that were able to escape elimination are selected for growth; and escape, whereby these resistant cancer cells overwhelm the immune system and develop into a symptomatic lesion.^4,5

Immuno-oncologists have also described the cancer immunity cycle to capture the steps that are required for an effective anti-tumor immune response and defects in this cycle form the basis of the most common mechanisms used by cancer cells to subvert the anti-tumor immune response. Much like the cancer hallmarks did for molecularly targeted cancer drugs, the cancer immunity cycle serves as the intellectual framework for cancer immunotherapy.^6,7

Exploiting nature’s weapon of mass destruction

Initially, attempts at immunotherapy focused on boosting the immune response using adjuvants and cytokines. The characterization of subtle differences between tumor cells and normal cells led to the development of vaccines and cell-based therapies that exploited these tumor-associated antigens (TAAs).^1-6

Despite the approval of a therapeutic vaccine, sipuleucel-T, in 2010 for the treatment of metastatic prostate cancer, in general the success of vaccines has been limited. Marketing authorization for sipuleucel-T was recently withdrawn in Europe, and although it is still available in the United States, it is not widely used because of issues with production and administration. Other vaccines, such as GVAX, which looked particularly promising in early-stage clinical trials, failed to show clinical efficacy in subsequent testing.^8,9

Cell-based therapies, such as adoptive cellular therapy (ACT), in which immune cells are removed from the host, primed to attack cancer cells, and then reinfused back into the patient, have focused on T cells because they are the major effectors of the adaptive immune response. Clinical success with the most common approach, tumor-infiltrating lymphocyte (TIL) therapy, has so far been limited to only one type of cancer – metastatic melanoma – but ACT may be inching closer to the mainstream with the development of techniques that allow genetic manipulation of the T cells before they are infused back into the patient.

Two key techniques have been developed (Figure 1). T-cell receptor (TCR) therapy involves genetically modifying the receptor on the surface of T cells that is responsible for recognizing antigens bound to major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells (APCs). The TCR can be altered to recognize a specific TAA or modified to improve its antigen recognition and binding capabilities. This type of therapy is limited by the fact that the TCRs need to be genetically matched to the patient’s immune type.

Releasing the brakes

To ensure that it is only activated at the appropriate time and not in response to the antigens expressed on the surface of the host’s own tissues or harmless materials, the immune system has developed numerous mechanisms for immunological tolerance. Cancer cells are able to exploit these mechanisms to allow them to evade the anti-tumor immune response. One of the main ways in which they do this is by manipulating the signaling pathways involved in T-cell activation, which play a vital role in tolerance.¹²

To become fully activated, T cells require a primary signal generated by an interaction between the TCR and the antigen-MHC complex on the surface of an APC, followed by secondary costimulatory signals generated by a range of different receptors present on the T-cell surface binding to their ligands on the APC.

If the second signal is inhibitory rather than stimulatory, then the T cell is deactivated instead of becoming activated. Two key coinhibitory receptors are programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) and tumor cells are able to overcome the anti-tumor immune response in part by expressing the ligands that bind these receptors to dampen the activity of tumor-infiltrating T cells and induce tolerance.¹³

The development of inhibitors of CTLA-4 and PD-1 and their respective ligands has driven some of the most dramatic successes with cancer immunotherapy, particularly with PD-1-targeting drugs which have fewer side effects. Targeting of this pathway has resulted in durable responses, revolutionizing the treatment of metastatic melanoma, with recently published long-term survival data for pembrolizumab showing that 40% of patients were alive 3 years after initiating treatment and, in a separate study, 34% of nivolumab-treated patients were still alive after 5 years.^14,15 More recently, PD-1 inhibitors have been slowly expanding into a range of other cancer types and 4 immune checkpoint inhibitors are now approved by the United States Food and Drug Administration (FDA): ipilimumab (Yervoy), nivolumab (Opdivo), pembrolizumab (Keytruda) and atezolizumab (Tecentriq).

Six years on from the first approval in this drug class and an extensive network of coinhibitory receptors has been uncovered – so-called immune checkpoints – many of which are now also serving as therapeutic targets (Table, Figure 2).¹⁶ Lymphocyte activation gene 3 (LAG-3) is a member of the immunoglobulin superfamily of receptors that is expressed on a number of different types of immune cell. In addition to negatively regulating cytotoxic T-cell activation like PD-1 and CTLA-4, it is also thought to regulate the immunosuppressive functions of regulatory T cells and the maturation and activation of dendritic cells. T-cell immunoglobulin and mucin domain-containing 3 (TIM-3) is found on the surface of helper and cytotoxic T cells and regulates T-cell inhibition as well as macrophage activation. Inhibitors of both proteins have been developed that are being evaluated in phase 1 or 2 clinical trials in a variety of tumor types.17

Indeed, although T cells have commanded the most attention, there is growing appreciation of the potential for targeting other types of immune cell that play a role in the anti-tumor immune response or in fostering an immunosuppressive microenvironment. NK cells have been a particular focus, since they represent the body’s first line of immune defense and they appear to have analogous inhibitory and activating receptors expressed on their surface that regulate their cytotoxic activity.

The best-defined NK cell receptors are the killer cell immunoglobulin-like receptors (KIRs) that bind to the MHC class I proteins found on the surface of all cells that distinguish them as ‘self’ or ‘non-self’. KIRs can be either activating or inhibitory, depending upon their structure and the ligands to which they bind.¹⁹ To date, 2 antibodies targeting inhibitory KIRs have been developed. Though there has been some disappointment with these drugs, most recently a phase 2 trial of lirilumab in elderly patients with acute myeloid leukemia, which missed its primary endpoint, they continue to be evaluated in clinical trials.²⁰

The inhibitory immune checkpoint field has also expanded to include molecules that regulate T-cell activity in other ways. Most prominently, this includes enzymes like indoleamine-2,3 dioxygenase (IDO), which is involved in the metabolism of the essential amino acid tryptophan. IDO-induced depletion of tryptophan and generation of tryptophan metabolites is toxic to cytotoxic T cells, and IDO is also thought to directly activate regulatory T cells, thus the net effect of IDO is immunosuppression. Two IDO inhibitors are currently being developed.²¹

Stepping on the gas

Despite their unprecedented success, immune checkpoint inhibitors are not effective in all patients or in all tumor types. Their efficacy is limited in large part by the requirement for a pre-existing anti-tumor immune response. If there are no T cells within the tumor microenvironment then releasing the brakes on the immune system won’t help.

More recently, researchers have returned to the idea of stimulating an anti-tumor immune response, this time by targeting the other side of the immune checkpoint coin, the costimulatory molecules. These drugs could prove more effective as they aren’t reliant on a pre-existing anti-tumor immune response. A number of agonist antibodies designed to target these receptors have now been developed and are undergoing clinical evaluation.²²

Furthest along in development are those targeting OX40, a costimulatory molecule that is upregulated on the surface of T cells once they have been fully activated by the TCR signal and an initial costimulatory signal. OX40 is thought to be involved in a more long-term immune response and in the formation of a memory response. A mouse monoclonal antibody had a potent immune-stimulating effect accompanied by the regression of at least 1 metastatic lesion in 30% of patients treated in a phase 1 clinical trial, but was limited by the generation of anti-mouse antibodies. 7 OX40 agonists are now in clinical development, 6 fully human monoclonal antibodies and 1 OX40 ligand-Fc fusion protein, MEDI-6383.²³

Combinations are key

Many researchers are now reaching the conclusion that combination therapy is likely to be key in expanding the scope of immunotherapy into currently unresponsive patient populations. Investigating rational combinations is already becoming a burgeoning area of the immuno-oncology field, with a variety of different strategies being tested.

Now the question becomes what are the optimal combinations and the timing and sequencing of combination therapy is likely to be a paramount consideration. Developing combinations that have distinct mechanisms of action or target multiple steps in the cancer immunity cycle offers the greatest potential for therapeutic synergy since this is most likely to address potential mechanisms of resistance by blocking other paths to immune evasion for cancer cells (Figure 3).

Given the expanding network of immune-checkpoint inhibitors and agonists, the focal point of combination therapy has been combining immune checkpoint-targeting drugs with different mechanisms of action, including those that would simultaneously release the brakes and step on the gas pedal. The vast majority of ongoing clinical trials of approved checkpoint inhibitors and the drugs in development listed in the table are combination trials.

These efforts yielded the first FDA-approved combination immunotherapy regimen in 2015; nivolumab and ipilimumab for the treatment of metastatic melanoma. Approval was based on the demonstration of improved ORR, prolonged response duration, and improved progression-free survival among 142 patients treated with the combination, compared to either drug alone.²⁴

The results of a phase 1/2 trial evaluating the combination of a 4-1BB receptor agonist urelumab with nivolumab in hematologic malignancies and solid tumors found the combination to be safe and particularly effective in patients with advanced/metastatic melanoma, with an ORR of 50%.²⁵ Nivolumab was also combined with the CD27 agonist varlilumab in a phase 1/2 clinical trial of patients with solid tumors, for which data was also recently released. Among 46 patients enrolled, primarily those with colorectal and ovarian cancer the combination had an acceptable safety profile and favorable changes in intratumoral immune biomarkers were observed. The phase 2 portion of the trial is ongoing.²⁶

Meanwhile, Incyte’s IDO inhibitor epacadostat has recently been making waves in combination with pembrolizumab in patients with advanced solid tumors. It demonstrated particularly promising clinical activity in patients with metastatic melanoma, with an overall response rate (ORR) of 57%, including 2 complete responses (CRs), prompting initiation of a phase 3 trial of this combination (NCT02752074).²⁷

The relationship between the immune system and tumors is complex and dynamic, and for immunotherapy to reach its full potential it will likely need to attack on multiple fronts. Here, we discuss some of the latest and most promising developments in the immuno-oncology field designed to build on the successes and address limitations.

The anti-tumor immune response

Cancer is a disease of genomic instability, whereby genetic alterations ranging from a single nucleotide to the whole chromosome level frequently occur. Although cancers derive from a patient’s own tissues, these genetic differences can mark the cancer cell as non-self, triggering an immune response to eliminate these cells.

The first hints of this anti-tumor immunity date back more than a century and a half and sparked the concept of mobilizing the immune system to treat patients.^1-3 Although early pioneers achieved little progress in this regard, their efforts provided invaluable insights into the complex and dynamic relationship between a tumor and the immune system that are now translating into real clinical successes.

We now understand that the immune system has a dual role in both restraining and promoting cancer development and have translated this understanding into the theory of cancer immunoediting. Immunoediting has three stages: elimination, wherein the tumor is seemingly destroyed by the innate and adaptive immune response; equilibrium, in which cancer cells that were able to escape elimination are selected for growth; and escape, whereby these resistant cancer cells overwhelm the immune system and develop into a symptomatic lesion.^4,5

Immuno-oncologists have also described the cancer immunity cycle to capture the steps that are required for an effective anti-tumor immune response and defects in this cycle form the basis of the most common mechanisms used by cancer cells to subvert the anti-tumor immune response. Much like the cancer hallmarks did for molecularly targeted cancer drugs, the cancer immunity cycle serves as the intellectual framework for cancer immunotherapy.^6,7

Exploiting nature’s weapon of mass destruction

Initially, attempts at immunotherapy focused on boosting the immune response using adjuvants and cytokines. The characterization of subtle differences between tumor cells and normal cells led to the development of vaccines and cell-based therapies that exploited these tumor-associated antigens (TAAs).^1-6

Despite the approval of a therapeutic vaccine, sipuleucel-T, in 2010 for the treatment of metastatic prostate cancer, in general the success of vaccines has been limited. Marketing authorization for sipuleucel-T was recently withdrawn in Europe, and although it is still available in the United States, it is not widely used because of issues with production and administration. Other vaccines, such as GVAX, which looked particularly promising in early-stage clinical trials, failed to show clinical efficacy in subsequent testing.^8,9

Cell-based therapies, such as adoptive cellular therapy (ACT), in which immune cells are removed from the host, primed to attack cancer cells, and then reinfused back into the patient, have focused on T cells because they are the major effectors of the adaptive immune response. Clinical success with the most common approach, tumor-infiltrating lymphocyte (TIL) therapy, has so far been limited to only one type of cancer – metastatic melanoma – but ACT may be inching closer to the mainstream with the development of techniques that allow genetic manipulation of the T cells before they are infused back into the patient.

Two key techniques have been developed (Figure 1). T-cell receptor (TCR) therapy involves genetically modifying the receptor on the surface of T cells that is responsible for recognizing antigens bound to major histocompatibility complex (MHC) molecules on the surface of antigen-presenting cells (APCs). The TCR can be altered to recognize a specific TAA or modified to improve its antigen recognition and binding capabilities. This type of therapy is limited by the fact that the TCRs need to be genetically matched to the patient’s immune type.

Releasing the brakes

To ensure that it is only activated at the appropriate time and not in response to the antigens expressed on the surface of the host’s own tissues or harmless materials, the immune system has developed numerous mechanisms for immunological tolerance. Cancer cells are able to exploit these mechanisms to allow them to evade the anti-tumor immune response. One of the main ways in which they do this is by manipulating the signaling pathways involved in T-cell activation, which play a vital role in tolerance.¹²

To become fully activated, T cells require a primary signal generated by an interaction between the TCR and the antigen-MHC complex on the surface of an APC, followed by secondary costimulatory signals generated by a range of different receptors present on the T-cell surface binding to their ligands on the APC.

If the second signal is inhibitory rather than stimulatory, then the T cell is deactivated instead of becoming activated. Two key coinhibitory receptors are programmed cell death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) and tumor cells are able to overcome the anti-tumor immune response in part by expressing the ligands that bind these receptors to dampen the activity of tumor-infiltrating T cells and induce tolerance.¹³

The development of inhibitors of CTLA-4 and PD-1 and their respective ligands has driven some of the most dramatic successes with cancer immunotherapy, particularly with PD-1-targeting drugs which have fewer side effects. Targeting of this pathway has resulted in durable responses, revolutionizing the treatment of metastatic melanoma, with recently published long-term survival data for pembrolizumab showing that 40% of patients were alive 3 years after initiating treatment and, in a separate study, 34% of nivolumab-treated patients were still alive after 5 years.^14,15 More recently, PD-1 inhibitors have been slowly expanding into a range of other cancer types and 4 immune checkpoint inhibitors are now approved by the United States Food and Drug Administration (FDA): ipilimumab (Yervoy), nivolumab (Opdivo), pembrolizumab (Keytruda) and atezolizumab (Tecentriq).

Six years on from the first approval in this drug class and an extensive network of coinhibitory receptors has been uncovered – so-called immune checkpoints – many of which are now also serving as therapeutic targets (Table, Figure 2).¹⁶ Lymphocyte activation gene 3 (LAG-3) is a member of the immunoglobulin superfamily of receptors that is expressed on a number of different types of immune cell. In addition to negatively regulating cytotoxic T-cell activation like PD-1 and CTLA-4, it is also thought to regulate the immunosuppressive functions of regulatory T cells and the maturation and activation of dendritic cells. T-cell immunoglobulin and mucin domain-containing 3 (TIM-3) is found on the surface of helper and cytotoxic T cells and regulates T-cell inhibition as well as macrophage activation. Inhibitors of both proteins have been developed that are being evaluated in phase 1 or 2 clinical trials in a variety of tumor types.17

Indeed, although T cells have commanded the most attention, there is growing appreciation of the potential for targeting other types of immune cell that play a role in the anti-tumor immune response or in fostering an immunosuppressive microenvironment. NK cells have been a particular focus, since they represent the body’s first line of immune defense and they appear to have analogous inhibitory and activating receptors expressed on their surface that regulate their cytotoxic activity.

The best-defined NK cell receptors are the killer cell immunoglobulin-like receptors (KIRs) that bind to the MHC class I proteins found on the surface of all cells that distinguish them as ‘self’ or ‘non-self’. KIRs can be either activating or inhibitory, depending upon their structure and the ligands to which they bind.¹⁹ To date, 2 antibodies targeting inhibitory KIRs have been developed. Though there has been some disappointment with these drugs, most recently a phase 2 trial of lirilumab in elderly patients with acute myeloid leukemia, which missed its primary endpoint, they continue to be evaluated in clinical trials.²⁰

The inhibitory immune checkpoint field has also expanded to include molecules that regulate T-cell activity in other ways. Most prominently, this includes enzymes like indoleamine-2,3 dioxygenase (IDO), which is involved in the metabolism of the essential amino acid tryptophan. IDO-induced depletion of tryptophan and generation of tryptophan metabolites is toxic to cytotoxic T cells, and IDO is also thought to directly activate regulatory T cells, thus the net effect of IDO is immunosuppression. Two IDO inhibitors are currently being developed.²¹

Stepping on the gas

Despite their unprecedented success, immune checkpoint inhibitors are not effective in all patients or in all tumor types. Their efficacy is limited in large part by the requirement for a pre-existing anti-tumor immune response. If there are no T cells within the tumor microenvironment then releasing the brakes on the immune system won’t help.

More recently, researchers have returned to the idea of stimulating an anti-tumor immune response, this time by targeting the other side of the immune checkpoint coin, the costimulatory molecules. These drugs could prove more effective as they aren’t reliant on a pre-existing anti-tumor immune response. A number of agonist antibodies designed to target these receptors have now been developed and are undergoing clinical evaluation.²²

Furthest along in development are those targeting OX40, a costimulatory molecule that is upregulated on the surface of T cells once they have been fully activated by the TCR signal and an initial costimulatory signal. OX40 is thought to be involved in a more long-term immune response and in the formation of a memory response. A mouse monoclonal antibody had a potent immune-stimulating effect accompanied by the regression of at least 1 metastatic lesion in 30% of patients treated in a phase 1 clinical trial, but was limited by the generation of anti-mouse antibodies. 7 OX40 agonists are now in clinical development, 6 fully human monoclonal antibodies and 1 OX40 ligand-Fc fusion protein, MEDI-6383.²³

Combinations are key

Many researchers are now reaching the conclusion that combination therapy is likely to be key in expanding the scope of immunotherapy into currently unresponsive patient populations. Investigating rational combinations is already becoming a burgeoning area of the immuno-oncology field, with a variety of different strategies being tested.

Now the question becomes what are the optimal combinations and the timing and sequencing of combination therapy is likely to be a paramount consideration. Developing combinations that have distinct mechanisms of action or target multiple steps in the cancer immunity cycle offers the greatest potential for therapeutic synergy since this is most likely to address potential mechanisms of resistance by blocking other paths to immune evasion for cancer cells (Figure 3).

Given the expanding network of immune-checkpoint inhibitors and agonists, the focal point of combination therapy has been combining immune checkpoint-targeting drugs with different mechanisms of action, including those that would simultaneously release the brakes and step on the gas pedal. The vast majority of ongoing clinical trials of approved checkpoint inhibitors and the drugs in development listed in the table are combination trials.

These efforts yielded the first FDA-approved combination immunotherapy regimen in 2015; nivolumab and ipilimumab for the treatment of metastatic melanoma. Approval was based on the demonstration of improved ORR, prolonged response duration, and improved progression-free survival among 142 patients treated with the combination, compared to either drug alone.²⁴

The results of a phase 1/2 trial evaluating the combination of a 4-1BB receptor agonist urelumab with nivolumab in hematologic malignancies and solid tumors found the combination to be safe and particularly effective in patients with advanced/metastatic melanoma, with an ORR of 50%.²⁵ Nivolumab was also combined with the CD27 agonist varlilumab in a phase 1/2 clinical trial of patients with solid tumors, for which data was also recently released. Among 46 patients enrolled, primarily those with colorectal and ovarian cancer the combination had an acceptable safety profile and favorable changes in intratumoral immune biomarkers were observed. The phase 2 portion of the trial is ongoing.²⁶

Meanwhile, Incyte’s IDO inhibitor epacadostat has recently been making waves in combination with pembrolizumab in patients with advanced solid tumors. It demonstrated particularly promising clinical activity in patients with metastatic melanoma, with an overall response rate (ORR) of 57%, including 2 complete responses (CRs), prompting initiation of a phase 3 trial of this combination (NCT02752074).²⁷