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Myasthenia Gravis Highlights From AANEM 2024
The latest data on myasthenia gravis (MG) research, reported at the American Association of Neuromuscular and Electrodiagnostic Medicine 2024 Annual Meeting, are presented by Dr Pushpa Narayanswami of Harvard Medical School in Boston, Massachusetts.
Dr Narayanswami begins with a safety, tolerability, and efficacy study for subcutaneous efgartigimod. Results showed that the mean change in MG activities of daily living (MG-ADL) was no different between the fixed-dose and cyclic regimens, demonstrating another dosage option for patients.
Next, Dr Narayanswami discusses two separate complement C5 inhibitor therapy trials. The first was a global registry study looking at ravulizumab. Patient cohorts consisted of those who started and remained on ravulizumab vs another that switched from initial eculizumab to ravulizumab. In both groups, MG-ADL was improved. The other study investigated zilucoplan in acetylcholine receptor autoantibody–positive generalized MG patient populations; similarly, researchers found favorable results.
She then details a study looking at the safety outcomes in pregnant patients treated with eculizumab. Because of limited disease-specific data in the registry, further investigation is recommended.
Finally, Dr Narayanaswami examines results for inebilizumab, a first-in-class anti-CD19 B cell–depleting agent. The drug demonstrated safety and beneficial efficacy compared with placebo in seropositive generalized MG patients.
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Pushpa Narayanaswami, MD, Associate Professor, Department of Neurology, Harvard Medical School; Vice Chair of Clinical Operations, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
Pushpa Narayanaswami, MD, has disclosed the following relevant financial relationships:
Serve(d) as an advisor or consultant for: Alexion; Argenx; Janssen; Dianthus; UCB; GSK
Received research grant from: Alexion; UCB; Dianthus; Janssen
The latest data on myasthenia gravis (MG) research, reported at the American Association of Neuromuscular and Electrodiagnostic Medicine 2024 Annual Meeting, are presented by Dr Pushpa Narayanswami of Harvard Medical School in Boston, Massachusetts.
Dr Narayanswami begins with a safety, tolerability, and efficacy study for subcutaneous efgartigimod. Results showed that the mean change in MG activities of daily living (MG-ADL) was no different between the fixed-dose and cyclic regimens, demonstrating another dosage option for patients.
Next, Dr Narayanswami discusses two separate complement C5 inhibitor therapy trials. The first was a global registry study looking at ravulizumab. Patient cohorts consisted of those who started and remained on ravulizumab vs another that switched from initial eculizumab to ravulizumab. In both groups, MG-ADL was improved. The other study investigated zilucoplan in acetylcholine receptor autoantibody–positive generalized MG patient populations; similarly, researchers found favorable results.
She then details a study looking at the safety outcomes in pregnant patients treated with eculizumab. Because of limited disease-specific data in the registry, further investigation is recommended.
Finally, Dr Narayanaswami examines results for inebilizumab, a first-in-class anti-CD19 B cell–depleting agent. The drug demonstrated safety and beneficial efficacy compared with placebo in seropositive generalized MG patients.
--
Pushpa Narayanaswami, MD, Associate Professor, Department of Neurology, Harvard Medical School; Vice Chair of Clinical Operations, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
Pushpa Narayanaswami, MD, has disclosed the following relevant financial relationships:
Serve(d) as an advisor or consultant for: Alexion; Argenx; Janssen; Dianthus; UCB; GSK
Received research grant from: Alexion; UCB; Dianthus; Janssen
The latest data on myasthenia gravis (MG) research, reported at the American Association of Neuromuscular and Electrodiagnostic Medicine 2024 Annual Meeting, are presented by Dr Pushpa Narayanswami of Harvard Medical School in Boston, Massachusetts.
Dr Narayanswami begins with a safety, tolerability, and efficacy study for subcutaneous efgartigimod. Results showed that the mean change in MG activities of daily living (MG-ADL) was no different between the fixed-dose and cyclic regimens, demonstrating another dosage option for patients.
Next, Dr Narayanswami discusses two separate complement C5 inhibitor therapy trials. The first was a global registry study looking at ravulizumab. Patient cohorts consisted of those who started and remained on ravulizumab vs another that switched from initial eculizumab to ravulizumab. In both groups, MG-ADL was improved. The other study investigated zilucoplan in acetylcholine receptor autoantibody–positive generalized MG patient populations; similarly, researchers found favorable results.
She then details a study looking at the safety outcomes in pregnant patients treated with eculizumab. Because of limited disease-specific data in the registry, further investigation is recommended.
Finally, Dr Narayanaswami examines results for inebilizumab, a first-in-class anti-CD19 B cell–depleting agent. The drug demonstrated safety and beneficial efficacy compared with placebo in seropositive generalized MG patients.
--
Pushpa Narayanaswami, MD, Associate Professor, Department of Neurology, Harvard Medical School; Vice Chair of Clinical Operations, Department of Neurology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
Pushpa Narayanaswami, MD, has disclosed the following relevant financial relationships:
Serve(d) as an advisor or consultant for: Alexion; Argenx; Janssen; Dianthus; UCB; GSK
Received research grant from: Alexion; UCB; Dianthus; Janssen
Myasthenia Gravis: Where Does Traditional Therapy Fit In?
SAVANNAH, GEORGIA —
In a debate at American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024, a pair of neurologists who specialize in neuromuscular disorders laid out opposing evidence for each approach.
On one hand, Benjamin Claytor, MD, of Cleveland Clinic, Cleveland, argued that “traditional therapy is very effective for the majority of myasthenia gravis patients,” and he said it should be considered first-line.
But Amanda C. Guidon, MD, MPH, of Massachusetts General Hospital and Harvard Medical School, both in Boston, responded that “the immunosuppression of traditional therapies is too broad: The time to benefit is too long, the burden of side effects is too high, and the cancer risk is too elevated.”
Traditional Therapy: Affordable, Tolerable, and Safe?
Claytor said ideal myasthenia gravis therapies are effective, tolerable, and safe. They’re also affordable, convenient (such as a pill), lead to sustained remission, and can have dosages reduced.
Only traditional therapies — corticosteroids, azathioprine, mycophenolate, and rituximab — meet those last three criteria, he said. Newer therapies, he said, do not.
Claytor highlighted a 2023 Duke University study that tracked 367 patients with MG who were treated with traditional therapies after the year 2000. Of those, 72% reached the treatment goal of minimal manifestations in a median of less than 2 years.
In addition, Claytor noted that the percentage of patients with myasthenia gravis who reach minimal symptom expression ranges from 45% (6 months) to 60% or more (2 years), while studies suggest that newer treatments such as eculizumab (Soliris), efgartigimod (Vyvgart), rozanolixizumab (Rystiggo), and zilucoplan (Zilbrysq) haven’t reached those levels.
As for specific traditional therapies, Claytor said the corticosteroid prednisone is “extremely affordable,” effective, and takes fewer than 2 weeks to work. All patients with myasthenia gravis can take it, he said, and at least 75% of those with mild/moderate disease respond to low doses.
Nonsteroidal Agents, Immune Globulin, Rituximab
He acknowledged side effects from corticosteroids but said doses can be tapered once severity improves. Calcium and vitamin D can be helpful to support bone health, he added.
As for nonsteroidal immunosuppressive treatments, he said they’re easy to administer, increase the likelihood of reaching minimal manifestation status, can be effective at lower doses, and may allow patients to discontinue steroids.
Two other traditional therapies, immune globulin and plasmapheresis, can be appropriate in crisis or impending crisis situations, he said, or as an add-on therapy if steroids and nonsteroidal immunosuppressive therapies don’t work.
What about rituximab? “We’re learning that patients with new-onset disease and younger patients seem to respond better,” Claytor said. While rituximab is expensive, it’s “not even in the same realm” as newer agents if only a dose or two are given, he said.
Steroids Are Ideal in MG? Not So Fast
In her response, Guidon noted that she was assigned to offer a counter-perspective in her presentation, and “personal opinions are not being represented here fully.” She then listed the weaknesses of traditional therapy in myasthenia gravis.
For one thing, she said the drugs don’t work well. She highlighted a 2019 registry study that found “many myasthenia gravis patients remain negatively impacted despite treatment.”
In addition, “we can’t predict who will respond to which therapy. ... We start drugs and don’t know if we’ll have benefit from 6 months up to 18 months. We also can’t determine minimally effective dose a priori. Some patients require higher doses, and some subtherapeutic doses are actually therapeutic for our patients.”
Broad immunosuppression, she added, boosts the risk for serious infections. “We’ve all heard from our patients that the side effects can be worse than the myasthenia, and next we’re going to talk about the role of corticosteroids in myasthenia.”
As for corticosteroids in particular, “they’re really the best treatment and also the worst treatment.” Efficacy and side effects battle for supremacy in patients, she said, “and you don’t know which is going to win out.”
Kicking Traditional Therapy to the Curb
There are many possible side effects from steroids, she said, including steroid-induced diabetes, which is “profound.” Some patients never recover from it.
On top of all these risks, she said, 20%-30% of patients are resistant to steroids.
As for other treatments, immune globulin and plasmapheresis “aren’t really benign,” Guidon said. They come with potentially serious side effects of their own, as do nonsteroidal immunosuppressive treatments.
Guidon said better treatments are needed to minimize the risks from traditional therapies. “We need targeted therapies that drive disease into remission, can be tapered, are delivered orally or with infrequent self-injections, and don’t require frequent lab monitoring.”
In addition, ideal treatments should “have a good safety data in pregnancy and for breastfeeding and have a favorable side effect profile with no significant long-term cancer risks.”
Claytor had no disclosures. Guidon disclosed consulting/medical advisory board (Alexion Pharmaceuticals, argenx, Regeneron, and UCB), publishing royalties (Oakstone), and other research support (Myasthenia Gravis Foundation of America, Myasthenia Gravis Rare Disease Network, National Institutes of Health, and National Institute of Neurological Disorders and Stroke/BioSensics).
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA —
In a debate at American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024, a pair of neurologists who specialize in neuromuscular disorders laid out opposing evidence for each approach.
On one hand, Benjamin Claytor, MD, of Cleveland Clinic, Cleveland, argued that “traditional therapy is very effective for the majority of myasthenia gravis patients,” and he said it should be considered first-line.
But Amanda C. Guidon, MD, MPH, of Massachusetts General Hospital and Harvard Medical School, both in Boston, responded that “the immunosuppression of traditional therapies is too broad: The time to benefit is too long, the burden of side effects is too high, and the cancer risk is too elevated.”
Traditional Therapy: Affordable, Tolerable, and Safe?
Claytor said ideal myasthenia gravis therapies are effective, tolerable, and safe. They’re also affordable, convenient (such as a pill), lead to sustained remission, and can have dosages reduced.
Only traditional therapies — corticosteroids, azathioprine, mycophenolate, and rituximab — meet those last three criteria, he said. Newer therapies, he said, do not.
Claytor highlighted a 2023 Duke University study that tracked 367 patients with MG who were treated with traditional therapies after the year 2000. Of those, 72% reached the treatment goal of minimal manifestations in a median of less than 2 years.
In addition, Claytor noted that the percentage of patients with myasthenia gravis who reach minimal symptom expression ranges from 45% (6 months) to 60% or more (2 years), while studies suggest that newer treatments such as eculizumab (Soliris), efgartigimod (Vyvgart), rozanolixizumab (Rystiggo), and zilucoplan (Zilbrysq) haven’t reached those levels.
As for specific traditional therapies, Claytor said the corticosteroid prednisone is “extremely affordable,” effective, and takes fewer than 2 weeks to work. All patients with myasthenia gravis can take it, he said, and at least 75% of those with mild/moderate disease respond to low doses.
Nonsteroidal Agents, Immune Globulin, Rituximab
He acknowledged side effects from corticosteroids but said doses can be tapered once severity improves. Calcium and vitamin D can be helpful to support bone health, he added.
As for nonsteroidal immunosuppressive treatments, he said they’re easy to administer, increase the likelihood of reaching minimal manifestation status, can be effective at lower doses, and may allow patients to discontinue steroids.
Two other traditional therapies, immune globulin and plasmapheresis, can be appropriate in crisis or impending crisis situations, he said, or as an add-on therapy if steroids and nonsteroidal immunosuppressive therapies don’t work.
What about rituximab? “We’re learning that patients with new-onset disease and younger patients seem to respond better,” Claytor said. While rituximab is expensive, it’s “not even in the same realm” as newer agents if only a dose or two are given, he said.
Steroids Are Ideal in MG? Not So Fast
In her response, Guidon noted that she was assigned to offer a counter-perspective in her presentation, and “personal opinions are not being represented here fully.” She then listed the weaknesses of traditional therapy in myasthenia gravis.
For one thing, she said the drugs don’t work well. She highlighted a 2019 registry study that found “many myasthenia gravis patients remain negatively impacted despite treatment.”
In addition, “we can’t predict who will respond to which therapy. ... We start drugs and don’t know if we’ll have benefit from 6 months up to 18 months. We also can’t determine minimally effective dose a priori. Some patients require higher doses, and some subtherapeutic doses are actually therapeutic for our patients.”
Broad immunosuppression, she added, boosts the risk for serious infections. “We’ve all heard from our patients that the side effects can be worse than the myasthenia, and next we’re going to talk about the role of corticosteroids in myasthenia.”
As for corticosteroids in particular, “they’re really the best treatment and also the worst treatment.” Efficacy and side effects battle for supremacy in patients, she said, “and you don’t know which is going to win out.”
Kicking Traditional Therapy to the Curb
There are many possible side effects from steroids, she said, including steroid-induced diabetes, which is “profound.” Some patients never recover from it.
On top of all these risks, she said, 20%-30% of patients are resistant to steroids.
As for other treatments, immune globulin and plasmapheresis “aren’t really benign,” Guidon said. They come with potentially serious side effects of their own, as do nonsteroidal immunosuppressive treatments.
Guidon said better treatments are needed to minimize the risks from traditional therapies. “We need targeted therapies that drive disease into remission, can be tapered, are delivered orally or with infrequent self-injections, and don’t require frequent lab monitoring.”
In addition, ideal treatments should “have a good safety data in pregnancy and for breastfeeding and have a favorable side effect profile with no significant long-term cancer risks.”
Claytor had no disclosures. Guidon disclosed consulting/medical advisory board (Alexion Pharmaceuticals, argenx, Regeneron, and UCB), publishing royalties (Oakstone), and other research support (Myasthenia Gravis Foundation of America, Myasthenia Gravis Rare Disease Network, National Institutes of Health, and National Institute of Neurological Disorders and Stroke/BioSensics).
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA —
In a debate at American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024, a pair of neurologists who specialize in neuromuscular disorders laid out opposing evidence for each approach.
On one hand, Benjamin Claytor, MD, of Cleveland Clinic, Cleveland, argued that “traditional therapy is very effective for the majority of myasthenia gravis patients,” and he said it should be considered first-line.
But Amanda C. Guidon, MD, MPH, of Massachusetts General Hospital and Harvard Medical School, both in Boston, responded that “the immunosuppression of traditional therapies is too broad: The time to benefit is too long, the burden of side effects is too high, and the cancer risk is too elevated.”
Traditional Therapy: Affordable, Tolerable, and Safe?
Claytor said ideal myasthenia gravis therapies are effective, tolerable, and safe. They’re also affordable, convenient (such as a pill), lead to sustained remission, and can have dosages reduced.
Only traditional therapies — corticosteroids, azathioprine, mycophenolate, and rituximab — meet those last three criteria, he said. Newer therapies, he said, do not.
Claytor highlighted a 2023 Duke University study that tracked 367 patients with MG who were treated with traditional therapies after the year 2000. Of those, 72% reached the treatment goal of minimal manifestations in a median of less than 2 years.
In addition, Claytor noted that the percentage of patients with myasthenia gravis who reach minimal symptom expression ranges from 45% (6 months) to 60% or more (2 years), while studies suggest that newer treatments such as eculizumab (Soliris), efgartigimod (Vyvgart), rozanolixizumab (Rystiggo), and zilucoplan (Zilbrysq) haven’t reached those levels.
As for specific traditional therapies, Claytor said the corticosteroid prednisone is “extremely affordable,” effective, and takes fewer than 2 weeks to work. All patients with myasthenia gravis can take it, he said, and at least 75% of those with mild/moderate disease respond to low doses.
Nonsteroidal Agents, Immune Globulin, Rituximab
He acknowledged side effects from corticosteroids but said doses can be tapered once severity improves. Calcium and vitamin D can be helpful to support bone health, he added.
As for nonsteroidal immunosuppressive treatments, he said they’re easy to administer, increase the likelihood of reaching minimal manifestation status, can be effective at lower doses, and may allow patients to discontinue steroids.
Two other traditional therapies, immune globulin and plasmapheresis, can be appropriate in crisis or impending crisis situations, he said, or as an add-on therapy if steroids and nonsteroidal immunosuppressive therapies don’t work.
What about rituximab? “We’re learning that patients with new-onset disease and younger patients seem to respond better,” Claytor said. While rituximab is expensive, it’s “not even in the same realm” as newer agents if only a dose or two are given, he said.
Steroids Are Ideal in MG? Not So Fast
In her response, Guidon noted that she was assigned to offer a counter-perspective in her presentation, and “personal opinions are not being represented here fully.” She then listed the weaknesses of traditional therapy in myasthenia gravis.
For one thing, she said the drugs don’t work well. She highlighted a 2019 registry study that found “many myasthenia gravis patients remain negatively impacted despite treatment.”
In addition, “we can’t predict who will respond to which therapy. ... We start drugs and don’t know if we’ll have benefit from 6 months up to 18 months. We also can’t determine minimally effective dose a priori. Some patients require higher doses, and some subtherapeutic doses are actually therapeutic for our patients.”
Broad immunosuppression, she added, boosts the risk for serious infections. “We’ve all heard from our patients that the side effects can be worse than the myasthenia, and next we’re going to talk about the role of corticosteroids in myasthenia.”
As for corticosteroids in particular, “they’re really the best treatment and also the worst treatment.” Efficacy and side effects battle for supremacy in patients, she said, “and you don’t know which is going to win out.”
Kicking Traditional Therapy to the Curb
There are many possible side effects from steroids, she said, including steroid-induced diabetes, which is “profound.” Some patients never recover from it.
On top of all these risks, she said, 20%-30% of patients are resistant to steroids.
As for other treatments, immune globulin and plasmapheresis “aren’t really benign,” Guidon said. They come with potentially serious side effects of their own, as do nonsteroidal immunosuppressive treatments.
Guidon said better treatments are needed to minimize the risks from traditional therapies. “We need targeted therapies that drive disease into remission, can be tapered, are delivered orally or with infrequent self-injections, and don’t require frequent lab monitoring.”
In addition, ideal treatments should “have a good safety data in pregnancy and for breastfeeding and have a favorable side effect profile with no significant long-term cancer risks.”
Claytor had no disclosures. Guidon disclosed consulting/medical advisory board (Alexion Pharmaceuticals, argenx, Regeneron, and UCB), publishing royalties (Oakstone), and other research support (Myasthenia Gravis Foundation of America, Myasthenia Gravis Rare Disease Network, National Institutes of Health, and National Institute of Neurological Disorders and Stroke/BioSensics).
A version of this article appeared on Medscape.com.
FROM AANEM 2024
Neurologists Lack Awareness of Steroid Toxicity
SAVANNAH, GEORGIA — , results of a US survey showed.
For both MG and CIDP specialists, uncertainty around corticosteroid dosing, duration, and toxicity underscores the need for more guidance, the investigators noted. Over 85% of respondents indicated that a tool for systematically monitoring corticosteroid toxicity would be valuable.
The results indicate “a lack of knowledge by this pool of neurologists about the guidelines and what they contain,” said study investigator Gil Wolfe, MD, professor of neurology at the Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, in New York.
Clearer guidance on how to administer corticosteroids and manage toxicities in patients with gMG and CIDP “would be welcomed by neurologists and have potential for benefit to patient care,” the team noted.
The findings were presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Lack of Knowledge
Although guidelines for both CIDP and gMG recommend corticosteroids as first-line treatment and emphasize using the lowest effective dose to control symptoms, they do not include specific recommendations on dosing, duration, or toxicity monitoring, the researchers noted.
Despite this, a large proportion of survey respondents reported using guidelines to make clinical decisions on monitoring toxicity, with up to a third actually endorsing a guideline that doesn’t exist.
The cross-sectional, online survey was deployed in November and December 2023 and included 200 US neurologists. Of these, 99 answered questions on CIDP, and 101 answered similar questions on gMG.
To participate in the survey, respondents had to be board-certified neurologists, practicing for at least 2 years post-residency, and have treated or consulted on at least three patients with CIDP or 10 patients with gMG in the past year who were on a corticosteroid dose of at least 10 mg daily for 1 month or more.
CIDP respondents had been practicing a mean of 18.1 years since residency and were board certified in neuromuscular (20%), electrodiagnostic medicine/clinical neurophysiology (21%), and pediatric neurology (8%). Two thirds of them accepted referrals from other neurologists.
The gMG respondents had been practicing a mean of 20.5 years since residency and were board certified in neuromuscular (45%), electrodiagnostic medicine/clinical neurophysiology (35%), and pediatric neurology (17%). A total of 72% accepted referrals from other neurologists.
Respondents estimated that about 60% of their patients with gMG and 58% of patients with CIDP were being treated with corticosteroids, with gMG and CIDP respondents reporting a mean of 26.4 and 15.6 patients, respectively, meeting the study’s dosing criteria.
Appropriate Dosing
When asked what chronic, long-term (≥ 6 months) corticosteroid dose they considered safe in terms of minimizing adverse events, 43% of CIDP respondents and 51% of gMG respondents considered corticosteroid doses of 10 mg/d or less (prednisone equivalent) well tolerated; additionally, 32% and 31%, respectively, considered 20-40 mg/d well tolerated. Moreover, they said only about half of their patients would be able to taper to less than 10 mg/d in less than 6 months.
“Studies suggest safety is not seen until patients are on doses at 5 mg/d or less,” Wolfe said. “There is not enough appreciation that doses at levels we once considered safe really do pose significant risk,” he added.
“With the increasing number of treatment options in MG and to a lesser extent in CIDP, we need to do all we can to use corticosteroids as judiciously as possible and be aware of side effects our patients may not even report unless we make a pointed effort to ask about them.”
Familiarity with corticosteroid toxicities was more common among gMG respondents, of whom 77% reported being very/extremely familiar, than among 55% of CIDP respondents. Appetite/weight gain was reported among the most common adverse effects (AEs) associated with long-term CS use (reported by 68% of CIDP and 58% of gMG respondents). Other common AEs reported were insulin resistance (53% of CIDP and 50% of gMG respondents), decreased bone density (47% and 48%, respectively), immunosuppression (37% and 45%, respectively). Mood and behavioral change were noted by 56% of CIDP and 37% of gMG respondents, particularly mood swings, irritability, mania, and sleep disorders.
When asked how they balanced the risk for and benefit of corticosteroids, more than 80% of CIDP specialists reported personally monitoring for corticosteroid-related toxicity, and 42% reported they collaborated with the patient’s primary care provider. However, fewer than 10% reported ordering lab tests. Among neurologists treating gMG, 84% said they typically monitor corticosteroid toxicity independently, while 41% reported doing so in collaboration with primary care providers.
Two thirds of CIDP respondents and 53% of gMG respondents reported using guidelines to make clinical decisions on monitoring toxicity, and 34% of gMG respondents actually endorsed using the Guideline for Systematic Surveillance of Steroid Safety, which does not exist.
‘A Big Issue’ in Neurology
Commenting on the results, Said R. Beydoun, MD, professor and division chief, Neuromuscular Medicine, Department of Neurology at Keck Medicine of University of Southern California, Los Angeles, said steroid toxicity is “a big issue” in neurology.
These patients can be on chronic therapy, and they aren’t really monitored for osteoporosis or other complications, he said, adding that neurologists aren’t always taking the necessary precautions to prevent steroid toxicity.
Beydoun estimated that about half of neurologists are not adequately familiar with balancing the efficacy of corticosteroids versus in toxicity.
“Objective improvement, either on the functional scale or the muscle impairment scale — that’s really response treatment. Whereas adverse effects of a treatment are something separate. The patient may be improving but also maybe developing other complications from the treatment,” he said.
Also commenting, Ghazala Hayat, MD, professor of neurology and director of neuromuscular and clinical neurophysiology services at Saint Louis University in St. Louis, said there is a clear need for more education.
“I always say prednisone is our best friend initially, and then it becomes the worst enemy. If you don’t see lots of neuromuscular patients, you might not know even how to recognize toxicity or how to taper. Or the opposite to that, if you taper too quickly, patients relapse.”
The study was funded by argenx. Wolfe reported serving on advisory boards for Alexion, argenx, UCB, and Johnson & Johnson. Neelam Goyal, MD, is a consultant/advisor for Alexion, argenx, Amgen, Janssen, Lycia Therapeutics, and UCB and has received grant support from argenx. Beydoun reported receiving research support and consulting and speaking fees from Healey Center, Amylyx, AB Science, Sanofi, Janssen, Genentech, Regeneron, UCB, Abcuro argenx, Alnylam, AstraZeneca, Amylyx, CSL Behring, Grifols, Takeda, Octapharma, UCB, and Janssen. Hayat reported speaker and advisory roles with argenx, Alexion, and MTPA.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA — , results of a US survey showed.
For both MG and CIDP specialists, uncertainty around corticosteroid dosing, duration, and toxicity underscores the need for more guidance, the investigators noted. Over 85% of respondents indicated that a tool for systematically monitoring corticosteroid toxicity would be valuable.
The results indicate “a lack of knowledge by this pool of neurologists about the guidelines and what they contain,” said study investigator Gil Wolfe, MD, professor of neurology at the Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, in New York.
Clearer guidance on how to administer corticosteroids and manage toxicities in patients with gMG and CIDP “would be welcomed by neurologists and have potential for benefit to patient care,” the team noted.
The findings were presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Lack of Knowledge
Although guidelines for both CIDP and gMG recommend corticosteroids as first-line treatment and emphasize using the lowest effective dose to control symptoms, they do not include specific recommendations on dosing, duration, or toxicity monitoring, the researchers noted.
Despite this, a large proportion of survey respondents reported using guidelines to make clinical decisions on monitoring toxicity, with up to a third actually endorsing a guideline that doesn’t exist.
The cross-sectional, online survey was deployed in November and December 2023 and included 200 US neurologists. Of these, 99 answered questions on CIDP, and 101 answered similar questions on gMG.
To participate in the survey, respondents had to be board-certified neurologists, practicing for at least 2 years post-residency, and have treated or consulted on at least three patients with CIDP or 10 patients with gMG in the past year who were on a corticosteroid dose of at least 10 mg daily for 1 month or more.
CIDP respondents had been practicing a mean of 18.1 years since residency and were board certified in neuromuscular (20%), electrodiagnostic medicine/clinical neurophysiology (21%), and pediatric neurology (8%). Two thirds of them accepted referrals from other neurologists.
The gMG respondents had been practicing a mean of 20.5 years since residency and were board certified in neuromuscular (45%), electrodiagnostic medicine/clinical neurophysiology (35%), and pediatric neurology (17%). A total of 72% accepted referrals from other neurologists.
Respondents estimated that about 60% of their patients with gMG and 58% of patients with CIDP were being treated with corticosteroids, with gMG and CIDP respondents reporting a mean of 26.4 and 15.6 patients, respectively, meeting the study’s dosing criteria.
Appropriate Dosing
When asked what chronic, long-term (≥ 6 months) corticosteroid dose they considered safe in terms of minimizing adverse events, 43% of CIDP respondents and 51% of gMG respondents considered corticosteroid doses of 10 mg/d or less (prednisone equivalent) well tolerated; additionally, 32% and 31%, respectively, considered 20-40 mg/d well tolerated. Moreover, they said only about half of their patients would be able to taper to less than 10 mg/d in less than 6 months.
“Studies suggest safety is not seen until patients are on doses at 5 mg/d or less,” Wolfe said. “There is not enough appreciation that doses at levels we once considered safe really do pose significant risk,” he added.
“With the increasing number of treatment options in MG and to a lesser extent in CIDP, we need to do all we can to use corticosteroids as judiciously as possible and be aware of side effects our patients may not even report unless we make a pointed effort to ask about them.”
Familiarity with corticosteroid toxicities was more common among gMG respondents, of whom 77% reported being very/extremely familiar, than among 55% of CIDP respondents. Appetite/weight gain was reported among the most common adverse effects (AEs) associated with long-term CS use (reported by 68% of CIDP and 58% of gMG respondents). Other common AEs reported were insulin resistance (53% of CIDP and 50% of gMG respondents), decreased bone density (47% and 48%, respectively), immunosuppression (37% and 45%, respectively). Mood and behavioral change were noted by 56% of CIDP and 37% of gMG respondents, particularly mood swings, irritability, mania, and sleep disorders.
When asked how they balanced the risk for and benefit of corticosteroids, more than 80% of CIDP specialists reported personally monitoring for corticosteroid-related toxicity, and 42% reported they collaborated with the patient’s primary care provider. However, fewer than 10% reported ordering lab tests. Among neurologists treating gMG, 84% said they typically monitor corticosteroid toxicity independently, while 41% reported doing so in collaboration with primary care providers.
Two thirds of CIDP respondents and 53% of gMG respondents reported using guidelines to make clinical decisions on monitoring toxicity, and 34% of gMG respondents actually endorsed using the Guideline for Systematic Surveillance of Steroid Safety, which does not exist.
‘A Big Issue’ in Neurology
Commenting on the results, Said R. Beydoun, MD, professor and division chief, Neuromuscular Medicine, Department of Neurology at Keck Medicine of University of Southern California, Los Angeles, said steroid toxicity is “a big issue” in neurology.
These patients can be on chronic therapy, and they aren’t really monitored for osteoporosis or other complications, he said, adding that neurologists aren’t always taking the necessary precautions to prevent steroid toxicity.
Beydoun estimated that about half of neurologists are not adequately familiar with balancing the efficacy of corticosteroids versus in toxicity.
“Objective improvement, either on the functional scale or the muscle impairment scale — that’s really response treatment. Whereas adverse effects of a treatment are something separate. The patient may be improving but also maybe developing other complications from the treatment,” he said.
Also commenting, Ghazala Hayat, MD, professor of neurology and director of neuromuscular and clinical neurophysiology services at Saint Louis University in St. Louis, said there is a clear need for more education.
“I always say prednisone is our best friend initially, and then it becomes the worst enemy. If you don’t see lots of neuromuscular patients, you might not know even how to recognize toxicity or how to taper. Or the opposite to that, if you taper too quickly, patients relapse.”
The study was funded by argenx. Wolfe reported serving on advisory boards for Alexion, argenx, UCB, and Johnson & Johnson. Neelam Goyal, MD, is a consultant/advisor for Alexion, argenx, Amgen, Janssen, Lycia Therapeutics, and UCB and has received grant support from argenx. Beydoun reported receiving research support and consulting and speaking fees from Healey Center, Amylyx, AB Science, Sanofi, Janssen, Genentech, Regeneron, UCB, Abcuro argenx, Alnylam, AstraZeneca, Amylyx, CSL Behring, Grifols, Takeda, Octapharma, UCB, and Janssen. Hayat reported speaker and advisory roles with argenx, Alexion, and MTPA.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA — , results of a US survey showed.
For both MG and CIDP specialists, uncertainty around corticosteroid dosing, duration, and toxicity underscores the need for more guidance, the investigators noted. Over 85% of respondents indicated that a tool for systematically monitoring corticosteroid toxicity would be valuable.
The results indicate “a lack of knowledge by this pool of neurologists about the guidelines and what they contain,” said study investigator Gil Wolfe, MD, professor of neurology at the Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, in New York.
Clearer guidance on how to administer corticosteroids and manage toxicities in patients with gMG and CIDP “would be welcomed by neurologists and have potential for benefit to patient care,” the team noted.
The findings were presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Lack of Knowledge
Although guidelines for both CIDP and gMG recommend corticosteroids as first-line treatment and emphasize using the lowest effective dose to control symptoms, they do not include specific recommendations on dosing, duration, or toxicity monitoring, the researchers noted.
Despite this, a large proportion of survey respondents reported using guidelines to make clinical decisions on monitoring toxicity, with up to a third actually endorsing a guideline that doesn’t exist.
The cross-sectional, online survey was deployed in November and December 2023 and included 200 US neurologists. Of these, 99 answered questions on CIDP, and 101 answered similar questions on gMG.
To participate in the survey, respondents had to be board-certified neurologists, practicing for at least 2 years post-residency, and have treated or consulted on at least three patients with CIDP or 10 patients with gMG in the past year who were on a corticosteroid dose of at least 10 mg daily for 1 month or more.
CIDP respondents had been practicing a mean of 18.1 years since residency and were board certified in neuromuscular (20%), electrodiagnostic medicine/clinical neurophysiology (21%), and pediatric neurology (8%). Two thirds of them accepted referrals from other neurologists.
The gMG respondents had been practicing a mean of 20.5 years since residency and were board certified in neuromuscular (45%), electrodiagnostic medicine/clinical neurophysiology (35%), and pediatric neurology (17%). A total of 72% accepted referrals from other neurologists.
Respondents estimated that about 60% of their patients with gMG and 58% of patients with CIDP were being treated with corticosteroids, with gMG and CIDP respondents reporting a mean of 26.4 and 15.6 patients, respectively, meeting the study’s dosing criteria.
Appropriate Dosing
When asked what chronic, long-term (≥ 6 months) corticosteroid dose they considered safe in terms of minimizing adverse events, 43% of CIDP respondents and 51% of gMG respondents considered corticosteroid doses of 10 mg/d or less (prednisone equivalent) well tolerated; additionally, 32% and 31%, respectively, considered 20-40 mg/d well tolerated. Moreover, they said only about half of their patients would be able to taper to less than 10 mg/d in less than 6 months.
“Studies suggest safety is not seen until patients are on doses at 5 mg/d or less,” Wolfe said. “There is not enough appreciation that doses at levels we once considered safe really do pose significant risk,” he added.
“With the increasing number of treatment options in MG and to a lesser extent in CIDP, we need to do all we can to use corticosteroids as judiciously as possible and be aware of side effects our patients may not even report unless we make a pointed effort to ask about them.”
Familiarity with corticosteroid toxicities was more common among gMG respondents, of whom 77% reported being very/extremely familiar, than among 55% of CIDP respondents. Appetite/weight gain was reported among the most common adverse effects (AEs) associated with long-term CS use (reported by 68% of CIDP and 58% of gMG respondents). Other common AEs reported were insulin resistance (53% of CIDP and 50% of gMG respondents), decreased bone density (47% and 48%, respectively), immunosuppression (37% and 45%, respectively). Mood and behavioral change were noted by 56% of CIDP and 37% of gMG respondents, particularly mood swings, irritability, mania, and sleep disorders.
When asked how they balanced the risk for and benefit of corticosteroids, more than 80% of CIDP specialists reported personally monitoring for corticosteroid-related toxicity, and 42% reported they collaborated with the patient’s primary care provider. However, fewer than 10% reported ordering lab tests. Among neurologists treating gMG, 84% said they typically monitor corticosteroid toxicity independently, while 41% reported doing so in collaboration with primary care providers.
Two thirds of CIDP respondents and 53% of gMG respondents reported using guidelines to make clinical decisions on monitoring toxicity, and 34% of gMG respondents actually endorsed using the Guideline for Systematic Surveillance of Steroid Safety, which does not exist.
‘A Big Issue’ in Neurology
Commenting on the results, Said R. Beydoun, MD, professor and division chief, Neuromuscular Medicine, Department of Neurology at Keck Medicine of University of Southern California, Los Angeles, said steroid toxicity is “a big issue” in neurology.
These patients can be on chronic therapy, and they aren’t really monitored for osteoporosis or other complications, he said, adding that neurologists aren’t always taking the necessary precautions to prevent steroid toxicity.
Beydoun estimated that about half of neurologists are not adequately familiar with balancing the efficacy of corticosteroids versus in toxicity.
“Objective improvement, either on the functional scale or the muscle impairment scale — that’s really response treatment. Whereas adverse effects of a treatment are something separate. The patient may be improving but also maybe developing other complications from the treatment,” he said.
Also commenting, Ghazala Hayat, MD, professor of neurology and director of neuromuscular and clinical neurophysiology services at Saint Louis University in St. Louis, said there is a clear need for more education.
“I always say prednisone is our best friend initially, and then it becomes the worst enemy. If you don’t see lots of neuromuscular patients, you might not know even how to recognize toxicity or how to taper. Or the opposite to that, if you taper too quickly, patients relapse.”
The study was funded by argenx. Wolfe reported serving on advisory boards for Alexion, argenx, UCB, and Johnson & Johnson. Neelam Goyal, MD, is a consultant/advisor for Alexion, argenx, Amgen, Janssen, Lycia Therapeutics, and UCB and has received grant support from argenx. Beydoun reported receiving research support and consulting and speaking fees from Healey Center, Amylyx, AB Science, Sanofi, Janssen, Genentech, Regeneron, UCB, Abcuro argenx, Alnylam, AstraZeneca, Amylyx, CSL Behring, Grifols, Takeda, Octapharma, UCB, and Janssen. Hayat reported speaker and advisory roles with argenx, Alexion, and MTPA.
A version of this article appeared on Medscape.com.
FROM AANEM 2024
Digital Tool May Help Neurologists Assess Steroid Toxicity
SAVANNAH, GEORGIA —
The Glucocorticoid Toxicity Index-Metabolic Domains (GTI-MD), an abbreviated version of the GTI (Steritas), used weighted, standardized clinical outcome assessments to calculate steroid toxicity using a de-identified electronic health record (EHR) dataset.
“The results of our study indicate that patients with MG who initiated steroids demonstrated evidence of steroid toxicity in as little as 90 days after initial exposure, which was significant for patients with 20+ mg at index with repeated use,” noted study investigators, led by Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California.
The findings were presented at American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Rapid Evidence of Toxicity
The GTI uses nine health domains to calculate steroid toxicity scores, and the GTI-MD, which has been shown to be closely correlated, uses four domains collected routinely in clinical practice: Body mass index (BMI), blood pressure, glucose tolerance, and lipid metabolism.
The study used the Optum EHR dataset to identify 682 adult patients with MG, mean age of 70 years, 38% women, with at least two confirmed diagnoses of MG between 30 and 730 days apart and information on steroid utilization.
Patients were divided into two groups: Steroid initiators (SI; n = 377) were those whose steroid use was already in progress at the index date, whereas steroid-naive (SN) patients (n = 305) began their steroid use at the index date. Among the SI group, 30% were on doses greater than 20 mg/d and 22% were on lower doses. Among the SN group, 22% were on doses greater than 20 mg/d and 26% were on lower doses.
As expected, mean GTI-MD scores measured 90 days after the index date were higher in the SI group than in the SN group, indicating a higher level of steroid toxicity in the SI group. This was measured with two subscores of the GTI-MD: The Cumulative Worsening Score (22.6 vs 18.7; P = .007) and the Aggregate Improvement Score (4.9 vs 1.9; P = .27), the latter incorporating resolved toxicities resulting from the introduction of steroid-sparing agents.
The authors commented that scores were higher in the SN group than expected, “which could be explained by age, previous steroid exposure, comorbidities, and side effects from other medications.” However, they concluded that the findings suggest utility of the tool retrospectively, with EHR data.
Clinical Application
The GTI and related measurements are proprietary tools and therefore not readily available to all clinicians, noted Marie Beaudin, MD, another neurologist at Stanford University School of Medicine, who was not involved in the research.
In a separate, observational, ongoing study, Beaudin and Goyal’s team are examining the use of the tool prospectively for following the steroid toxicity burden in 50 patients with MG and correlating it with MG outcomes measured using the MG-Activities of Daily Living, MG Composite, and MG-Quality of Life 15R validated scales, as well as the adverse event unit.
“The objective of this study is to quantify the burden of toxicity that our patients are having from glucocorticoids, see how sensitive to change the scale is as their dosage of prednisone changes, and explore the correlations between the score and their disease outcome measures,” Beaudin said.
Unlike the abbreviated GTI-MD, the GTI measures nine domains: Bone mineral density, BMI, lipid metabolism, blood pressure, glucose tolerance, myopathy, skin toxicity, neuropsychiatric symptoms, and infections.
The score involves actively prompting and examining the patient, making it quite comprehensive. Beaudin said the study has revealed interesting insights into how patients report their side effects. When asked broadly about steroid-related side effects, many patients mention issues like weight or skin issues.
However, she noted, when prompted specifically about symptoms like insomnia, irritability, depression, or cognitive changes, there was an unexpected increase in positive responses, as patients are often unaware these could be side effects. This suggests the study may capture a greater burden than originally anticipated, said Beaudin.
She added that the long-term utility of the GTI score might be to help clinicians predict steroid toxicity and guide management.
“Then we would get more aggressive in trying to wean or taper patients. But these are often complicated cases because as soon as we taper, the disease flares. It’s a difficult decision whether to reduce the dosage of prednisone because toxicity burden is high, when disease burden is high too, and that’s where other medications can come into play.”
For example, she said, for insurance coverage, a high steroid toxicity score could justify the need to initiate more expensive steroid-sparing agents.
Both studies were funded by argenx. Goyal reported that she has consulted and received grant support from argenx, UCB, Alexion, and Janssen argenx. Beaudin is supported by a McLaughlin Scholarship from Laval University, Quebec, Canada.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA —
The Glucocorticoid Toxicity Index-Metabolic Domains (GTI-MD), an abbreviated version of the GTI (Steritas), used weighted, standardized clinical outcome assessments to calculate steroid toxicity using a de-identified electronic health record (EHR) dataset.
“The results of our study indicate that patients with MG who initiated steroids demonstrated evidence of steroid toxicity in as little as 90 days after initial exposure, which was significant for patients with 20+ mg at index with repeated use,” noted study investigators, led by Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California.
The findings were presented at American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Rapid Evidence of Toxicity
The GTI uses nine health domains to calculate steroid toxicity scores, and the GTI-MD, which has been shown to be closely correlated, uses four domains collected routinely in clinical practice: Body mass index (BMI), blood pressure, glucose tolerance, and lipid metabolism.
The study used the Optum EHR dataset to identify 682 adult patients with MG, mean age of 70 years, 38% women, with at least two confirmed diagnoses of MG between 30 and 730 days apart and information on steroid utilization.
Patients were divided into two groups: Steroid initiators (SI; n = 377) were those whose steroid use was already in progress at the index date, whereas steroid-naive (SN) patients (n = 305) began their steroid use at the index date. Among the SI group, 30% were on doses greater than 20 mg/d and 22% were on lower doses. Among the SN group, 22% were on doses greater than 20 mg/d and 26% were on lower doses.
As expected, mean GTI-MD scores measured 90 days after the index date were higher in the SI group than in the SN group, indicating a higher level of steroid toxicity in the SI group. This was measured with two subscores of the GTI-MD: The Cumulative Worsening Score (22.6 vs 18.7; P = .007) and the Aggregate Improvement Score (4.9 vs 1.9; P = .27), the latter incorporating resolved toxicities resulting from the introduction of steroid-sparing agents.
The authors commented that scores were higher in the SN group than expected, “which could be explained by age, previous steroid exposure, comorbidities, and side effects from other medications.” However, they concluded that the findings suggest utility of the tool retrospectively, with EHR data.
Clinical Application
The GTI and related measurements are proprietary tools and therefore not readily available to all clinicians, noted Marie Beaudin, MD, another neurologist at Stanford University School of Medicine, who was not involved in the research.
In a separate, observational, ongoing study, Beaudin and Goyal’s team are examining the use of the tool prospectively for following the steroid toxicity burden in 50 patients with MG and correlating it with MG outcomes measured using the MG-Activities of Daily Living, MG Composite, and MG-Quality of Life 15R validated scales, as well as the adverse event unit.
“The objective of this study is to quantify the burden of toxicity that our patients are having from glucocorticoids, see how sensitive to change the scale is as their dosage of prednisone changes, and explore the correlations between the score and their disease outcome measures,” Beaudin said.
Unlike the abbreviated GTI-MD, the GTI measures nine domains: Bone mineral density, BMI, lipid metabolism, blood pressure, glucose tolerance, myopathy, skin toxicity, neuropsychiatric symptoms, and infections.
The score involves actively prompting and examining the patient, making it quite comprehensive. Beaudin said the study has revealed interesting insights into how patients report their side effects. When asked broadly about steroid-related side effects, many patients mention issues like weight or skin issues.
However, she noted, when prompted specifically about symptoms like insomnia, irritability, depression, or cognitive changes, there was an unexpected increase in positive responses, as patients are often unaware these could be side effects. This suggests the study may capture a greater burden than originally anticipated, said Beaudin.
She added that the long-term utility of the GTI score might be to help clinicians predict steroid toxicity and guide management.
“Then we would get more aggressive in trying to wean or taper patients. But these are often complicated cases because as soon as we taper, the disease flares. It’s a difficult decision whether to reduce the dosage of prednisone because toxicity burden is high, when disease burden is high too, and that’s where other medications can come into play.”
For example, she said, for insurance coverage, a high steroid toxicity score could justify the need to initiate more expensive steroid-sparing agents.
Both studies were funded by argenx. Goyal reported that she has consulted and received grant support from argenx, UCB, Alexion, and Janssen argenx. Beaudin is supported by a McLaughlin Scholarship from Laval University, Quebec, Canada.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA —
The Glucocorticoid Toxicity Index-Metabolic Domains (GTI-MD), an abbreviated version of the GTI (Steritas), used weighted, standardized clinical outcome assessments to calculate steroid toxicity using a de-identified electronic health record (EHR) dataset.
“The results of our study indicate that patients with MG who initiated steroids demonstrated evidence of steroid toxicity in as little as 90 days after initial exposure, which was significant for patients with 20+ mg at index with repeated use,” noted study investigators, led by Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California.
The findings were presented at American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Rapid Evidence of Toxicity
The GTI uses nine health domains to calculate steroid toxicity scores, and the GTI-MD, which has been shown to be closely correlated, uses four domains collected routinely in clinical practice: Body mass index (BMI), blood pressure, glucose tolerance, and lipid metabolism.
The study used the Optum EHR dataset to identify 682 adult patients with MG, mean age of 70 years, 38% women, with at least two confirmed diagnoses of MG between 30 and 730 days apart and information on steroid utilization.
Patients were divided into two groups: Steroid initiators (SI; n = 377) were those whose steroid use was already in progress at the index date, whereas steroid-naive (SN) patients (n = 305) began their steroid use at the index date. Among the SI group, 30% were on doses greater than 20 mg/d and 22% were on lower doses. Among the SN group, 22% were on doses greater than 20 mg/d and 26% were on lower doses.
As expected, mean GTI-MD scores measured 90 days after the index date were higher in the SI group than in the SN group, indicating a higher level of steroid toxicity in the SI group. This was measured with two subscores of the GTI-MD: The Cumulative Worsening Score (22.6 vs 18.7; P = .007) and the Aggregate Improvement Score (4.9 vs 1.9; P = .27), the latter incorporating resolved toxicities resulting from the introduction of steroid-sparing agents.
The authors commented that scores were higher in the SN group than expected, “which could be explained by age, previous steroid exposure, comorbidities, and side effects from other medications.” However, they concluded that the findings suggest utility of the tool retrospectively, with EHR data.
Clinical Application
The GTI and related measurements are proprietary tools and therefore not readily available to all clinicians, noted Marie Beaudin, MD, another neurologist at Stanford University School of Medicine, who was not involved in the research.
In a separate, observational, ongoing study, Beaudin and Goyal’s team are examining the use of the tool prospectively for following the steroid toxicity burden in 50 patients with MG and correlating it with MG outcomes measured using the MG-Activities of Daily Living, MG Composite, and MG-Quality of Life 15R validated scales, as well as the adverse event unit.
“The objective of this study is to quantify the burden of toxicity that our patients are having from glucocorticoids, see how sensitive to change the scale is as their dosage of prednisone changes, and explore the correlations between the score and their disease outcome measures,” Beaudin said.
Unlike the abbreviated GTI-MD, the GTI measures nine domains: Bone mineral density, BMI, lipid metabolism, blood pressure, glucose tolerance, myopathy, skin toxicity, neuropsychiatric symptoms, and infections.
The score involves actively prompting and examining the patient, making it quite comprehensive. Beaudin said the study has revealed interesting insights into how patients report their side effects. When asked broadly about steroid-related side effects, many patients mention issues like weight or skin issues.
However, she noted, when prompted specifically about symptoms like insomnia, irritability, depression, or cognitive changes, there was an unexpected increase in positive responses, as patients are often unaware these could be side effects. This suggests the study may capture a greater burden than originally anticipated, said Beaudin.
She added that the long-term utility of the GTI score might be to help clinicians predict steroid toxicity and guide management.
“Then we would get more aggressive in trying to wean or taper patients. But these are often complicated cases because as soon as we taper, the disease flares. It’s a difficult decision whether to reduce the dosage of prednisone because toxicity burden is high, when disease burden is high too, and that’s where other medications can come into play.”
For example, she said, for insurance coverage, a high steroid toxicity score could justify the need to initiate more expensive steroid-sparing agents.
Both studies were funded by argenx. Goyal reported that she has consulted and received grant support from argenx, UCB, Alexion, and Janssen argenx. Beaudin is supported by a McLaughlin Scholarship from Laval University, Quebec, Canada.
A version of this article appeared on Medscape.com.
FROM AANEM 2024
Pediatric Myasthenia Gravis: Don’t Treat Children Like Adults
SAVANNAH, GEORGIA — At a pathophysiological level, juvenile myasthenia gravis (MG) seems to be identical to the adult form, neuromuscular specialists learned. But there are still important differences between children and their elders that affect pediatric care.
For example, “we have to think a little bit differently about the side effect profiles of the medications and their toxicity because children may react to medications differently,” said Matthew Ginsberg, MD, a pediatric neurologist based in Akron, Ohio, in a presentation at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
And then there’s the matter of adherence. “It’s hard to get adults to take medication, but a teenager is sometimes an exceptional challenge,” Ginsberg said.
Case In Point: A 13-Year-Old With MG
Pediatric MG is rare. Cases in children are estimated to account for 10% of MG cases diagnosed each year. According to a 2020 report, “the majority will present with ptosis and a variable degree of ophthalmoplegia [paralysis of eye muscles].”
Ginsberg highlighted a case of a 13-year-old girl who’d been healthy but developed fatigable ptosis and mild restriction of extraocular movements. The patient’s acetylcholine receptor antibodies were very elevated, but she didn’t have MuSK antibodies.
“This isn’t a diagnostic conundrum. She has autoimmune myasthenia gravis with ocular manifestations,” Ginsberg said. “For someone like this, whether it’s an adult or a child, many people would start symptomatic treatment with an acetylcholinesterase inhibitor like pyridostigmine.”
The use of the drug in children is similar to that in adults, he said, although weight-based dosing is used. “Usually it’s around 3-7 mg/kg/d, but it’s still very individualized based on patient response.” The timing of symptoms can affect the distribution of doses throughout the day, he said.
“There are extended-release formulations of the medication, and I think some people use them more than I do,” he said. “The side effects are basically similar to adults. Most of the patients I have on it tolerate it really well and don’t have a lot of the muscarinic side effects that you would expect.”
Consider Prescription Eye Drops for Ptosis
Alpha-1A agonists oxymetazoline and apraclonidine in the form of topical eye drops can help with ptosis. “They potentially avoid some of the systemic toxicity of the other medications,” Ginsberg said. “So they might be an option if you’re really just trying to target ptosis as a symptom.”
However, it can be difficult to get insurers to cover these medications, he said.
The 13-year-old patient initially improved but developed difficulty walking. “Her hands began to feel heavy, and she had difficulty chewing and nasal regurgitation. On her exam, she still had fatigable ptosis plus hypernasal speech and generalized weakness. At this point, we’re starting to see that she has generalized myasthenia gravis that may be an impending crisis.”
The Young Patient Worsens. Now What?
The patient was admitted and given intravenous immunoglobulin at 2 g/kg over a couple days. But her symptoms worsened following initial improvement.
Glucocorticoids can play a larger role in treatment at this stage, and the patient was initially on prednisone. But there are reasons for caution, including effects on bone growth and interference with live vaccines.
However, live vaccines aren’t common in children, with the exception of the MMRV vaccine, he said. “It’s worth noting that you can give that second dose as early as 3 months after the initial one, so most patients really should be able to complete a course before they start on immunosuppression,” he said.
Another option is immunotherapy. “There’s a really large menu of options for immunotherapy in myasthenia gravis right now,” Ginsberg said. “It’s great that we have all these options, but it adds to the complexity.”
Rituximab may be considered based on early data, he said. And thymectomy — removal of the thymus gland — should be considered early.
Don’t Neglect Supportive Care
Ginsberg urged colleagues to consider supportive care measures. Advocacy groups such as the Myasthenia Gravis Foundation of America can help with weight management and diet/exercise counseling, especially in patients taking glucocorticoids.
He added that “school accommodations are very important in this age group. They might need a plan, for example, to have modified gym class or an excuse not to carry a book bag between classes.”
How did the 13-year-old do? She underwent thymectomy, and her disease remained stable after 6 months. “Her rituximab was discontinued,” Ginsberg said. “She considered participating in a clinical trial but then started seeing improvements. About a year after the thymectomy, she just stopped her steroids on her own, and she was fine.”
Ginsberg had no disclosures.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA — At a pathophysiological level, juvenile myasthenia gravis (MG) seems to be identical to the adult form, neuromuscular specialists learned. But there are still important differences between children and their elders that affect pediatric care.
For example, “we have to think a little bit differently about the side effect profiles of the medications and their toxicity because children may react to medications differently,” said Matthew Ginsberg, MD, a pediatric neurologist based in Akron, Ohio, in a presentation at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
And then there’s the matter of adherence. “It’s hard to get adults to take medication, but a teenager is sometimes an exceptional challenge,” Ginsberg said.
Case In Point: A 13-Year-Old With MG
Pediatric MG is rare. Cases in children are estimated to account for 10% of MG cases diagnosed each year. According to a 2020 report, “the majority will present with ptosis and a variable degree of ophthalmoplegia [paralysis of eye muscles].”
Ginsberg highlighted a case of a 13-year-old girl who’d been healthy but developed fatigable ptosis and mild restriction of extraocular movements. The patient’s acetylcholine receptor antibodies were very elevated, but she didn’t have MuSK antibodies.
“This isn’t a diagnostic conundrum. She has autoimmune myasthenia gravis with ocular manifestations,” Ginsberg said. “For someone like this, whether it’s an adult or a child, many people would start symptomatic treatment with an acetylcholinesterase inhibitor like pyridostigmine.”
The use of the drug in children is similar to that in adults, he said, although weight-based dosing is used. “Usually it’s around 3-7 mg/kg/d, but it’s still very individualized based on patient response.” The timing of symptoms can affect the distribution of doses throughout the day, he said.
“There are extended-release formulations of the medication, and I think some people use them more than I do,” he said. “The side effects are basically similar to adults. Most of the patients I have on it tolerate it really well and don’t have a lot of the muscarinic side effects that you would expect.”
Consider Prescription Eye Drops for Ptosis
Alpha-1A agonists oxymetazoline and apraclonidine in the form of topical eye drops can help with ptosis. “They potentially avoid some of the systemic toxicity of the other medications,” Ginsberg said. “So they might be an option if you’re really just trying to target ptosis as a symptom.”
However, it can be difficult to get insurers to cover these medications, he said.
The 13-year-old patient initially improved but developed difficulty walking. “Her hands began to feel heavy, and she had difficulty chewing and nasal regurgitation. On her exam, she still had fatigable ptosis plus hypernasal speech and generalized weakness. At this point, we’re starting to see that she has generalized myasthenia gravis that may be an impending crisis.”
The Young Patient Worsens. Now What?
The patient was admitted and given intravenous immunoglobulin at 2 g/kg over a couple days. But her symptoms worsened following initial improvement.
Glucocorticoids can play a larger role in treatment at this stage, and the patient was initially on prednisone. But there are reasons for caution, including effects on bone growth and interference with live vaccines.
However, live vaccines aren’t common in children, with the exception of the MMRV vaccine, he said. “It’s worth noting that you can give that second dose as early as 3 months after the initial one, so most patients really should be able to complete a course before they start on immunosuppression,” he said.
Another option is immunotherapy. “There’s a really large menu of options for immunotherapy in myasthenia gravis right now,” Ginsberg said. “It’s great that we have all these options, but it adds to the complexity.”
Rituximab may be considered based on early data, he said. And thymectomy — removal of the thymus gland — should be considered early.
Don’t Neglect Supportive Care
Ginsberg urged colleagues to consider supportive care measures. Advocacy groups such as the Myasthenia Gravis Foundation of America can help with weight management and diet/exercise counseling, especially in patients taking glucocorticoids.
He added that “school accommodations are very important in this age group. They might need a plan, for example, to have modified gym class or an excuse not to carry a book bag between classes.”
How did the 13-year-old do? She underwent thymectomy, and her disease remained stable after 6 months. “Her rituximab was discontinued,” Ginsberg said. “She considered participating in a clinical trial but then started seeing improvements. About a year after the thymectomy, she just stopped her steroids on her own, and she was fine.”
Ginsberg had no disclosures.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA — At a pathophysiological level, juvenile myasthenia gravis (MG) seems to be identical to the adult form, neuromuscular specialists learned. But there are still important differences between children and their elders that affect pediatric care.
For example, “we have to think a little bit differently about the side effect profiles of the medications and their toxicity because children may react to medications differently,” said Matthew Ginsberg, MD, a pediatric neurologist based in Akron, Ohio, in a presentation at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
And then there’s the matter of adherence. “It’s hard to get adults to take medication, but a teenager is sometimes an exceptional challenge,” Ginsberg said.
Case In Point: A 13-Year-Old With MG
Pediatric MG is rare. Cases in children are estimated to account for 10% of MG cases diagnosed each year. According to a 2020 report, “the majority will present with ptosis and a variable degree of ophthalmoplegia [paralysis of eye muscles].”
Ginsberg highlighted a case of a 13-year-old girl who’d been healthy but developed fatigable ptosis and mild restriction of extraocular movements. The patient’s acetylcholine receptor antibodies were very elevated, but she didn’t have MuSK antibodies.
“This isn’t a diagnostic conundrum. She has autoimmune myasthenia gravis with ocular manifestations,” Ginsberg said. “For someone like this, whether it’s an adult or a child, many people would start symptomatic treatment with an acetylcholinesterase inhibitor like pyridostigmine.”
The use of the drug in children is similar to that in adults, he said, although weight-based dosing is used. “Usually it’s around 3-7 mg/kg/d, but it’s still very individualized based on patient response.” The timing of symptoms can affect the distribution of doses throughout the day, he said.
“There are extended-release formulations of the medication, and I think some people use them more than I do,” he said. “The side effects are basically similar to adults. Most of the patients I have on it tolerate it really well and don’t have a lot of the muscarinic side effects that you would expect.”
Consider Prescription Eye Drops for Ptosis
Alpha-1A agonists oxymetazoline and apraclonidine in the form of topical eye drops can help with ptosis. “They potentially avoid some of the systemic toxicity of the other medications,” Ginsberg said. “So they might be an option if you’re really just trying to target ptosis as a symptom.”
However, it can be difficult to get insurers to cover these medications, he said.
The 13-year-old patient initially improved but developed difficulty walking. “Her hands began to feel heavy, and she had difficulty chewing and nasal regurgitation. On her exam, she still had fatigable ptosis plus hypernasal speech and generalized weakness. At this point, we’re starting to see that she has generalized myasthenia gravis that may be an impending crisis.”
The Young Patient Worsens. Now What?
The patient was admitted and given intravenous immunoglobulin at 2 g/kg over a couple days. But her symptoms worsened following initial improvement.
Glucocorticoids can play a larger role in treatment at this stage, and the patient was initially on prednisone. But there are reasons for caution, including effects on bone growth and interference with live vaccines.
However, live vaccines aren’t common in children, with the exception of the MMRV vaccine, he said. “It’s worth noting that you can give that second dose as early as 3 months after the initial one, so most patients really should be able to complete a course before they start on immunosuppression,” he said.
Another option is immunotherapy. “There’s a really large menu of options for immunotherapy in myasthenia gravis right now,” Ginsberg said. “It’s great that we have all these options, but it adds to the complexity.”
Rituximab may be considered based on early data, he said. And thymectomy — removal of the thymus gland — should be considered early.
Don’t Neglect Supportive Care
Ginsberg urged colleagues to consider supportive care measures. Advocacy groups such as the Myasthenia Gravis Foundation of America can help with weight management and diet/exercise counseling, especially in patients taking glucocorticoids.
He added that “school accommodations are very important in this age group. They might need a plan, for example, to have modified gym class or an excuse not to carry a book bag between classes.”
How did the 13-year-old do? She underwent thymectomy, and her disease remained stable after 6 months. “Her rituximab was discontinued,” Ginsberg said. “She considered participating in a clinical trial but then started seeing improvements. About a year after the thymectomy, she just stopped her steroids on her own, and she was fine.”
Ginsberg had no disclosures.
A version of this article appeared on Medscape.com.
FROM AANEM 2024
Myasthenia Gravis: Similar Symptoms in Relatives Raise Question of Genes
SAVANNAH, GEORGIA — One patient with autoimmune myasthenia gravis (MG) has a niece with the same diagnosis, and at least one of his other close relatives may have it too. Another patient with MG lost his father and brother to complications from the disease, while a surviving brother also has it. These two cases, reported at a meeting of nerve/muscle specialists, spotlight one of the mysteries of MG: What role does heredity play in this disorder?
“Clinical familial associations — when transmission appears to be vertical, from parent to offspring — suggest that there is much yet to learn about genetic bases for autoimmunity and how certain mutations could favor selection for specific immune disorders,” said Elena Shanina, MD, PhD, a neurology professor at the University of Texas Medical Branch, Galveston, in an interview. She and colleagues presented the two case reports at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
As Shanina noted, MG is usually sporadic without a link to heredity. However, she said, research suggests that up to 7% of patients have MG in their family history.
“There are well-described genetic causes for congenital myasthenic syndromes, in which mutations occur in genes for neuromuscular junction (NMJ) proteins affecting NMJ function. However, much less is known about genetic associations to autoimmune MG,” she said.
“More than a decade ago, differences in HLA DQ haplotype-associated presentation of AChR alpha-chain peptides were suggested to suffice in producing MG, and specific HLA DQ susceptibility links were found predisposing to MG. More recent studies have tried to identify specific genes such as CTLA4 mutations that enhance autoimmunity and neuroinflammation.”
Two Cases
In one of the case reports, a 75-year-old White man with hereditary coagulopathy presented with myasthenic crisis in the setting of acute pulmonary embolism. Chronic symptoms included diplopia, ptosis, and proximal muscle weakness.
A niece of the patient has been diagnosed with MG and suffers from ocular symptoms. Meanwhile, an uncle has ptosis but no diagnosis yet, and a daughter has dermatomyositis. Like MG, dermatomyositis is an autoimmune disease that causes muscle weakness.
The patient, who’s CTLA4 negative, is faring well on eculizumab after failing standard therapies, Shanina said.
In the other case, a 67-year-old Hispanic man presented with diplopia, generalized fatigue, and weakness. Like the other patient, he was seropositive for acetylcholine receptor antibodies.
This patient lost his father and brother to complications from MG. Another brother, who’s still living, also has MG.
“The patient has minimal manifestation status with disease and is currently controlled using oral immunomodulatory therapies,” Shanina said. “He is also CTLA4 negative.”
Genetics and Environment May Each Play a Role
Shanina called for research exploring mutations and inheritance patterns in families with MG.
“If there are genetic causes that increase autoimmunity with specific propensity for certain immune diseases, correcting those mutations could fundamentally change how we treat — and prevent — at least some autoimmune diseases,” she said. “For example, if HLA linkage is directly involved in determining susceptibility to MG, and if the presence of a specific HLA locus allele is sufficient to produce disease, HLA gene editing could be a future therapy to prevent such diseases. Likewise, monoclonal antibodies that target products of genes that increase risk for autoimmunity might be able to reduce such risks without modifying the patient’s genome.”
Henry J. Kaminski, MD, professor of neurology at George Washington University, Washington, DC, is familiar with the report’s findings. In an interview, he noted that while genetic profiles can make MG more likely, “the situation is not like Huntington’s or Alzheimer’s where there is a strong genetic risk.”
Instead, he said, there’s “a genetic risk coupled to some environmental stimulus that leads to the development of MG, which is true for many complex autoimmune conditions.”
While he doesn’t think the two new case reports are especially noteworthy, Kaminski said “the ability to assess genetic risk factors across patients will elucidate understanding of MG. Personalized medicine choices will likely require understanding of genetic risks.”
While understanding MG in families is “always good to know from a research perspective,” there’s no reason to launch surveillance of relatives to see if they also have the disease, he said.
Also, Kaminski cautioned that it’s important to differentiate autoimmune MG from congenital myasthenia, an even more rare genetic disorder of neuromuscular transmission. “Congenital myasthenias will not improve with immune therapy, and patients will suffer complications for no reason,” he said. “A patient who is seronegative should be assessed for congenital myasthenia with the right clinical presentation. The condition would be more likely in patients with a family history of symptoms similar to MG. It may be symptomatic at birth, but patients may present in adulthood.”
Kaminski noted that his team is collecting saliva samples from patients with MuSK-MG, a rare MG subtype linked to more severe cases, for genetic testing and genome-wide association studies.
There was no study funding, and the authors have no disclosures. Kaminski is principal investigator of a rare disease network dedicated to MG.
A version of this article first appeared on Medscape.com.
SAVANNAH, GEORGIA — One patient with autoimmune myasthenia gravis (MG) has a niece with the same diagnosis, and at least one of his other close relatives may have it too. Another patient with MG lost his father and brother to complications from the disease, while a surviving brother also has it. These two cases, reported at a meeting of nerve/muscle specialists, spotlight one of the mysteries of MG: What role does heredity play in this disorder?
“Clinical familial associations — when transmission appears to be vertical, from parent to offspring — suggest that there is much yet to learn about genetic bases for autoimmunity and how certain mutations could favor selection for specific immune disorders,” said Elena Shanina, MD, PhD, a neurology professor at the University of Texas Medical Branch, Galveston, in an interview. She and colleagues presented the two case reports at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
As Shanina noted, MG is usually sporadic without a link to heredity. However, she said, research suggests that up to 7% of patients have MG in their family history.
“There are well-described genetic causes for congenital myasthenic syndromes, in which mutations occur in genes for neuromuscular junction (NMJ) proteins affecting NMJ function. However, much less is known about genetic associations to autoimmune MG,” she said.
“More than a decade ago, differences in HLA DQ haplotype-associated presentation of AChR alpha-chain peptides were suggested to suffice in producing MG, and specific HLA DQ susceptibility links were found predisposing to MG. More recent studies have tried to identify specific genes such as CTLA4 mutations that enhance autoimmunity and neuroinflammation.”
Two Cases
In one of the case reports, a 75-year-old White man with hereditary coagulopathy presented with myasthenic crisis in the setting of acute pulmonary embolism. Chronic symptoms included diplopia, ptosis, and proximal muscle weakness.
A niece of the patient has been diagnosed with MG and suffers from ocular symptoms. Meanwhile, an uncle has ptosis but no diagnosis yet, and a daughter has dermatomyositis. Like MG, dermatomyositis is an autoimmune disease that causes muscle weakness.
The patient, who’s CTLA4 negative, is faring well on eculizumab after failing standard therapies, Shanina said.
In the other case, a 67-year-old Hispanic man presented with diplopia, generalized fatigue, and weakness. Like the other patient, he was seropositive for acetylcholine receptor antibodies.
This patient lost his father and brother to complications from MG. Another brother, who’s still living, also has MG.
“The patient has minimal manifestation status with disease and is currently controlled using oral immunomodulatory therapies,” Shanina said. “He is also CTLA4 negative.”
Genetics and Environment May Each Play a Role
Shanina called for research exploring mutations and inheritance patterns in families with MG.
“If there are genetic causes that increase autoimmunity with specific propensity for certain immune diseases, correcting those mutations could fundamentally change how we treat — and prevent — at least some autoimmune diseases,” she said. “For example, if HLA linkage is directly involved in determining susceptibility to MG, and if the presence of a specific HLA locus allele is sufficient to produce disease, HLA gene editing could be a future therapy to prevent such diseases. Likewise, monoclonal antibodies that target products of genes that increase risk for autoimmunity might be able to reduce such risks without modifying the patient’s genome.”
Henry J. Kaminski, MD, professor of neurology at George Washington University, Washington, DC, is familiar with the report’s findings. In an interview, he noted that while genetic profiles can make MG more likely, “the situation is not like Huntington’s or Alzheimer’s where there is a strong genetic risk.”
Instead, he said, there’s “a genetic risk coupled to some environmental stimulus that leads to the development of MG, which is true for many complex autoimmune conditions.”
While he doesn’t think the two new case reports are especially noteworthy, Kaminski said “the ability to assess genetic risk factors across patients will elucidate understanding of MG. Personalized medicine choices will likely require understanding of genetic risks.”
While understanding MG in families is “always good to know from a research perspective,” there’s no reason to launch surveillance of relatives to see if they also have the disease, he said.
Also, Kaminski cautioned that it’s important to differentiate autoimmune MG from congenital myasthenia, an even more rare genetic disorder of neuromuscular transmission. “Congenital myasthenias will not improve with immune therapy, and patients will suffer complications for no reason,” he said. “A patient who is seronegative should be assessed for congenital myasthenia with the right clinical presentation. The condition would be more likely in patients with a family history of symptoms similar to MG. It may be symptomatic at birth, but patients may present in adulthood.”
Kaminski noted that his team is collecting saliva samples from patients with MuSK-MG, a rare MG subtype linked to more severe cases, for genetic testing and genome-wide association studies.
There was no study funding, and the authors have no disclosures. Kaminski is principal investigator of a rare disease network dedicated to MG.
A version of this article first appeared on Medscape.com.
SAVANNAH, GEORGIA — One patient with autoimmune myasthenia gravis (MG) has a niece with the same diagnosis, and at least one of his other close relatives may have it too. Another patient with MG lost his father and brother to complications from the disease, while a surviving brother also has it. These two cases, reported at a meeting of nerve/muscle specialists, spotlight one of the mysteries of MG: What role does heredity play in this disorder?
“Clinical familial associations — when transmission appears to be vertical, from parent to offspring — suggest that there is much yet to learn about genetic bases for autoimmunity and how certain mutations could favor selection for specific immune disorders,” said Elena Shanina, MD, PhD, a neurology professor at the University of Texas Medical Branch, Galveston, in an interview. She and colleagues presented the two case reports at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
As Shanina noted, MG is usually sporadic without a link to heredity. However, she said, research suggests that up to 7% of patients have MG in their family history.
“There are well-described genetic causes for congenital myasthenic syndromes, in which mutations occur in genes for neuromuscular junction (NMJ) proteins affecting NMJ function. However, much less is known about genetic associations to autoimmune MG,” she said.
“More than a decade ago, differences in HLA DQ haplotype-associated presentation of AChR alpha-chain peptides were suggested to suffice in producing MG, and specific HLA DQ susceptibility links were found predisposing to MG. More recent studies have tried to identify specific genes such as CTLA4 mutations that enhance autoimmunity and neuroinflammation.”
Two Cases
In one of the case reports, a 75-year-old White man with hereditary coagulopathy presented with myasthenic crisis in the setting of acute pulmonary embolism. Chronic symptoms included diplopia, ptosis, and proximal muscle weakness.
A niece of the patient has been diagnosed with MG and suffers from ocular symptoms. Meanwhile, an uncle has ptosis but no diagnosis yet, and a daughter has dermatomyositis. Like MG, dermatomyositis is an autoimmune disease that causes muscle weakness.
The patient, who’s CTLA4 negative, is faring well on eculizumab after failing standard therapies, Shanina said.
In the other case, a 67-year-old Hispanic man presented with diplopia, generalized fatigue, and weakness. Like the other patient, he was seropositive for acetylcholine receptor antibodies.
This patient lost his father and brother to complications from MG. Another brother, who’s still living, also has MG.
“The patient has minimal manifestation status with disease and is currently controlled using oral immunomodulatory therapies,” Shanina said. “He is also CTLA4 negative.”
Genetics and Environment May Each Play a Role
Shanina called for research exploring mutations and inheritance patterns in families with MG.
“If there are genetic causes that increase autoimmunity with specific propensity for certain immune diseases, correcting those mutations could fundamentally change how we treat — and prevent — at least some autoimmune diseases,” she said. “For example, if HLA linkage is directly involved in determining susceptibility to MG, and if the presence of a specific HLA locus allele is sufficient to produce disease, HLA gene editing could be a future therapy to prevent such diseases. Likewise, monoclonal antibodies that target products of genes that increase risk for autoimmunity might be able to reduce such risks without modifying the patient’s genome.”
Henry J. Kaminski, MD, professor of neurology at George Washington University, Washington, DC, is familiar with the report’s findings. In an interview, he noted that while genetic profiles can make MG more likely, “the situation is not like Huntington’s or Alzheimer’s where there is a strong genetic risk.”
Instead, he said, there’s “a genetic risk coupled to some environmental stimulus that leads to the development of MG, which is true for many complex autoimmune conditions.”
While he doesn’t think the two new case reports are especially noteworthy, Kaminski said “the ability to assess genetic risk factors across patients will elucidate understanding of MG. Personalized medicine choices will likely require understanding of genetic risks.”
While understanding MG in families is “always good to know from a research perspective,” there’s no reason to launch surveillance of relatives to see if they also have the disease, he said.
Also, Kaminski cautioned that it’s important to differentiate autoimmune MG from congenital myasthenia, an even more rare genetic disorder of neuromuscular transmission. “Congenital myasthenias will not improve with immune therapy, and patients will suffer complications for no reason,” he said. “A patient who is seronegative should be assessed for congenital myasthenia with the right clinical presentation. The condition would be more likely in patients with a family history of symptoms similar to MG. It may be symptomatic at birth, but patients may present in adulthood.”
Kaminski noted that his team is collecting saliva samples from patients with MuSK-MG, a rare MG subtype linked to more severe cases, for genetic testing and genome-wide association studies.
There was no study funding, and the authors have no disclosures. Kaminski is principal investigator of a rare disease network dedicated to MG.
A version of this article first appeared on Medscape.com.
FROM AANEM 2024
Sustained Control with Investigational Monoclonal Antibody for Myasthenia Gravis
SAVANNAH, GEORGIA – , according to topline results from the phase 3 VIVACITY-MG3 study.
The VIVACITY-MG3 trial is the first registrational study of a neonatal fragment crystallizable receptor (FcRn) blocker to show sustained efficacy through 6 months of fixed schedule dosing.
Lead investigator Tuan Vu, MD, professor of neurology at the University of South Florida in Tampa, presented the findings at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Autoantibody Depletion
FcRN plays a crucial role in the transport of immunoglobulin G. Blocking it can reduce circulating immunoglobulin G antibodies, including pathogenic gMG autoantibodies.
The double-blind, placebo-controlled trial included 196 adults with a broad range of seropositive gMG – who account for approximately 95% of the gMG patient population – and 42 seronegative patients.
The mean age was 52 years, 92% were female, and 63% were White. The mean disease duration was about 8 years. Among seropositive patients, 87.6% were acetylcholine receptor autoantibody-positive (AChR+), 10.5% were muscle-specific kinase autoantibody-positive (MuSK+), and 2% were low-density lipoprotein receptor-related protein 4 antibody positive.
They were randomly assigned 1:1 to receive either nipocalimab IV plus standard of care, or placebo plus standard of care for 24 weeks. A total of 87 patients in the nipocalimab arm and 82 in the placebo arm completed the study.
The primary efficacy endpoint was the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Participants treated with nipocalimab demonstrated a statistically significant improvement of 4.70 points from baseline, compared to the 3.25-point improvement in those treated with placebo (P =.002).
Clinically Meaningful Changes?
“For someone living with gMG, a 1 to 2-point improvement on MG-ADL may be the difference between normal eating and frequent choking on food, or shortness of breath at rest and being on a ventilator,” the drug’s manufacturer noted in a release.
Secondary endpoints were also better in the nipocalimab group, compared with participants on placebo. Specifically, on the 13-item clinician assessed Quantitative Myasthenia Gravis disease severity score, patients who received nipocalimab had an average reduction of 4.86 points from baseline compared to a reduction of 2.05 points in the placebo arm (P <.001).
Similarly, MG-ADL response (defined as ≥ 2-point improvement from baseline) was significantly greater in the nipocalimab versus placebo arms (68.8% vs 52.6%; P =.021).
Subgroup analysis revealed similar results for the different types of seropositive patients, but there was no statistically significant difference in results for seronegative patients treated with nipocalimab versus placebo.
“The drug was pretty well tolerated and there was little difference, other than more patients with muscle spasm in the nipocalimab group (12.2% vs 3.1%),” said Vu.
In addition, peripheral edema occurred in 11.2% of the nipocalimab group and none of the placebo-treated patients. Cholesterol levels were also higher in the nipocalimab arm, but there were no cardiac side effects, he added.
Encouraging Findings
Commenting on the findings, Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, was encouraged.
“It’s a phase 3 trial, it’s positive, which is great, so it’ll be another drug on the market, another option for our patients,” she said. However, she cautioned, “their placebo arm did better than most placebos, so I think the delta is not as robust, but it was still statistically significant.”
Goyal noted that, if approved, nipocalimab will be the third FcRn inhibitor in the MG field, preceded by efgartigimod (Vyvgart), which is approved for AChR antibody-positive disease, and rozanolixizumab-noli (Rystiggo) which is approved for both for AChR and MUSK antibody positive disease.
“Its target of action is similar to the two drugs that are already on the market, but one thing that is unique about nipocalimab is that it is continuous dosing versus the other two medications that are given cyclically,” she said.
“The reason that’s an upside, is that with cyclical dosing, patients have a return of symptoms. We treat, they get better, and then they get worse. That’s very disconcerting to patients. So, they want to be treated continuously.”
Additionally, she said there are some early data suggesting its safety in pregnancy.
Vu disclosed he is the USF Site Principal Investigator for MG clinical trials sponsored by Alexion/ AstraZeneca Rare Disease, Amgen, argenx, Cartesian Therapeutics, COUR Pharmaceuticals, Dianthus Therapeutics, Immunovant, Johnson & Johnson, NMD Pharmaceuticals, Regeneron Pharmaceuticals, and UCB, and has served as a speaker for Alexion/AstraZeneca Rare Disease, argenx, and CSL Behring. He performs consulting work for Alexion/AstraZeneca Rare Disease, argenx, Dianthus Therapeutics, ImmunAbs, and UCB. Goyal disclosed consultant, advisory or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Janssen.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA – , according to topline results from the phase 3 VIVACITY-MG3 study.
The VIVACITY-MG3 trial is the first registrational study of a neonatal fragment crystallizable receptor (FcRn) blocker to show sustained efficacy through 6 months of fixed schedule dosing.
Lead investigator Tuan Vu, MD, professor of neurology at the University of South Florida in Tampa, presented the findings at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Autoantibody Depletion
FcRN plays a crucial role in the transport of immunoglobulin G. Blocking it can reduce circulating immunoglobulin G antibodies, including pathogenic gMG autoantibodies.
The double-blind, placebo-controlled trial included 196 adults with a broad range of seropositive gMG – who account for approximately 95% of the gMG patient population – and 42 seronegative patients.
The mean age was 52 years, 92% were female, and 63% were White. The mean disease duration was about 8 years. Among seropositive patients, 87.6% were acetylcholine receptor autoantibody-positive (AChR+), 10.5% were muscle-specific kinase autoantibody-positive (MuSK+), and 2% were low-density lipoprotein receptor-related protein 4 antibody positive.
They were randomly assigned 1:1 to receive either nipocalimab IV plus standard of care, or placebo plus standard of care for 24 weeks. A total of 87 patients in the nipocalimab arm and 82 in the placebo arm completed the study.
The primary efficacy endpoint was the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Participants treated with nipocalimab demonstrated a statistically significant improvement of 4.70 points from baseline, compared to the 3.25-point improvement in those treated with placebo (P =.002).
Clinically Meaningful Changes?
“For someone living with gMG, a 1 to 2-point improvement on MG-ADL may be the difference between normal eating and frequent choking on food, or shortness of breath at rest and being on a ventilator,” the drug’s manufacturer noted in a release.
Secondary endpoints were also better in the nipocalimab group, compared with participants on placebo. Specifically, on the 13-item clinician assessed Quantitative Myasthenia Gravis disease severity score, patients who received nipocalimab had an average reduction of 4.86 points from baseline compared to a reduction of 2.05 points in the placebo arm (P <.001).
Similarly, MG-ADL response (defined as ≥ 2-point improvement from baseline) was significantly greater in the nipocalimab versus placebo arms (68.8% vs 52.6%; P =.021).
Subgroup analysis revealed similar results for the different types of seropositive patients, but there was no statistically significant difference in results for seronegative patients treated with nipocalimab versus placebo.
“The drug was pretty well tolerated and there was little difference, other than more patients with muscle spasm in the nipocalimab group (12.2% vs 3.1%),” said Vu.
In addition, peripheral edema occurred in 11.2% of the nipocalimab group and none of the placebo-treated patients. Cholesterol levels were also higher in the nipocalimab arm, but there were no cardiac side effects, he added.
Encouraging Findings
Commenting on the findings, Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, was encouraged.
“It’s a phase 3 trial, it’s positive, which is great, so it’ll be another drug on the market, another option for our patients,” she said. However, she cautioned, “their placebo arm did better than most placebos, so I think the delta is not as robust, but it was still statistically significant.”
Goyal noted that, if approved, nipocalimab will be the third FcRn inhibitor in the MG field, preceded by efgartigimod (Vyvgart), which is approved for AChR antibody-positive disease, and rozanolixizumab-noli (Rystiggo) which is approved for both for AChR and MUSK antibody positive disease.
“Its target of action is similar to the two drugs that are already on the market, but one thing that is unique about nipocalimab is that it is continuous dosing versus the other two medications that are given cyclically,” she said.
“The reason that’s an upside, is that with cyclical dosing, patients have a return of symptoms. We treat, they get better, and then they get worse. That’s very disconcerting to patients. So, they want to be treated continuously.”
Additionally, she said there are some early data suggesting its safety in pregnancy.
Vu disclosed he is the USF Site Principal Investigator for MG clinical trials sponsored by Alexion/ AstraZeneca Rare Disease, Amgen, argenx, Cartesian Therapeutics, COUR Pharmaceuticals, Dianthus Therapeutics, Immunovant, Johnson & Johnson, NMD Pharmaceuticals, Regeneron Pharmaceuticals, and UCB, and has served as a speaker for Alexion/AstraZeneca Rare Disease, argenx, and CSL Behring. He performs consulting work for Alexion/AstraZeneca Rare Disease, argenx, Dianthus Therapeutics, ImmunAbs, and UCB. Goyal disclosed consultant, advisory or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Janssen.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA – , according to topline results from the phase 3 VIVACITY-MG3 study.
The VIVACITY-MG3 trial is the first registrational study of a neonatal fragment crystallizable receptor (FcRn) blocker to show sustained efficacy through 6 months of fixed schedule dosing.
Lead investigator Tuan Vu, MD, professor of neurology at the University of South Florida in Tampa, presented the findings at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Autoantibody Depletion
FcRN plays a crucial role in the transport of immunoglobulin G. Blocking it can reduce circulating immunoglobulin G antibodies, including pathogenic gMG autoantibodies.
The double-blind, placebo-controlled trial included 196 adults with a broad range of seropositive gMG – who account for approximately 95% of the gMG patient population – and 42 seronegative patients.
The mean age was 52 years, 92% were female, and 63% were White. The mean disease duration was about 8 years. Among seropositive patients, 87.6% were acetylcholine receptor autoantibody-positive (AChR+), 10.5% were muscle-specific kinase autoantibody-positive (MuSK+), and 2% were low-density lipoprotein receptor-related protein 4 antibody positive.
They were randomly assigned 1:1 to receive either nipocalimab IV plus standard of care, or placebo plus standard of care for 24 weeks. A total of 87 patients in the nipocalimab arm and 82 in the placebo arm completed the study.
The primary efficacy endpoint was the Myasthenia Gravis Activities of Daily Living (MG-ADL) score. Participants treated with nipocalimab demonstrated a statistically significant improvement of 4.70 points from baseline, compared to the 3.25-point improvement in those treated with placebo (P =.002).
Clinically Meaningful Changes?
“For someone living with gMG, a 1 to 2-point improvement on MG-ADL may be the difference between normal eating and frequent choking on food, or shortness of breath at rest and being on a ventilator,” the drug’s manufacturer noted in a release.
Secondary endpoints were also better in the nipocalimab group, compared with participants on placebo. Specifically, on the 13-item clinician assessed Quantitative Myasthenia Gravis disease severity score, patients who received nipocalimab had an average reduction of 4.86 points from baseline compared to a reduction of 2.05 points in the placebo arm (P <.001).
Similarly, MG-ADL response (defined as ≥ 2-point improvement from baseline) was significantly greater in the nipocalimab versus placebo arms (68.8% vs 52.6%; P =.021).
Subgroup analysis revealed similar results for the different types of seropositive patients, but there was no statistically significant difference in results for seronegative patients treated with nipocalimab versus placebo.
“The drug was pretty well tolerated and there was little difference, other than more patients with muscle spasm in the nipocalimab group (12.2% vs 3.1%),” said Vu.
In addition, peripheral edema occurred in 11.2% of the nipocalimab group and none of the placebo-treated patients. Cholesterol levels were also higher in the nipocalimab arm, but there were no cardiac side effects, he added.
Encouraging Findings
Commenting on the findings, Neelam Goyal, MD, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, was encouraged.
“It’s a phase 3 trial, it’s positive, which is great, so it’ll be another drug on the market, another option for our patients,” she said. However, she cautioned, “their placebo arm did better than most placebos, so I think the delta is not as robust, but it was still statistically significant.”
Goyal noted that, if approved, nipocalimab will be the third FcRn inhibitor in the MG field, preceded by efgartigimod (Vyvgart), which is approved for AChR antibody-positive disease, and rozanolixizumab-noli (Rystiggo) which is approved for both for AChR and MUSK antibody positive disease.
“Its target of action is similar to the two drugs that are already on the market, but one thing that is unique about nipocalimab is that it is continuous dosing versus the other two medications that are given cyclically,” she said.
“The reason that’s an upside, is that with cyclical dosing, patients have a return of symptoms. We treat, they get better, and then they get worse. That’s very disconcerting to patients. So, they want to be treated continuously.”
Additionally, she said there are some early data suggesting its safety in pregnancy.
Vu disclosed he is the USF Site Principal Investigator for MG clinical trials sponsored by Alexion/ AstraZeneca Rare Disease, Amgen, argenx, Cartesian Therapeutics, COUR Pharmaceuticals, Dianthus Therapeutics, Immunovant, Johnson & Johnson, NMD Pharmaceuticals, Regeneron Pharmaceuticals, and UCB, and has served as a speaker for Alexion/AstraZeneca Rare Disease, argenx, and CSL Behring. He performs consulting work for Alexion/AstraZeneca Rare Disease, argenx, Dianthus Therapeutics, ImmunAbs, and UCB. Goyal disclosed consultant, advisory or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Janssen.
A version of this article appeared on Medscape.com.
FROM AANEM 2024
First-in-Class B-Cell Depleting Agent Promising for Myasthenia Gravis
SAVANNAH, GEORGIA — , new phase 3 data showed.
“Based on these results, we have demonstrated that targeting B cells, including the antibody-secreting cells, is beneficial, and there is likely a role for this kind of therapeutic strategy for patients with myasthenia gravis,” said senior investigator Richard Nowak, MD.
The findings were published and presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Largest Cohort of Muscle-Specific Kinase (MuSK) Antibody–Positive Disease
The Myasthenia Gravis INebilizumab Trial study enrolled 238 participants, 60.8% women, mean age 47.5 years, from 79 sites in 18 countries. The participants were divided into two cohorts: 190 acetylcholine receptor (AChR) autoantibody–positive patients and 48 MuSK autoantibody–positive patients.
“This is the largest enrolled cohort of MuSK antibody–positive disease in a placebo-controlled trial to date,” said Nowak, director of the Yale Myasthenia Gravis Clinic and associate professor of neurology at Yale School of Medicine, in New Haven, Connecticut.
Both groups had similar gMG duration (mean 6.7 and 5.2 years for AChR+ and MuSK+ patients, respectively) and disease severity based on Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) baseline score. In addition, more than 80% of participants were on a prednisone equivalent dose greater than 5 mg daily at study entry.
Participants were randomly assigned to receive intravenous (IV) inebilizumab or IV placebo for 52 weeks (AChR+ group) or 26 weeks (MuSK+ group). In addition, study participants who were taking corticosteroids were tapered down starting at week 4 to prednisone 5 mg per day by week 24.
The trial met its primary endpoint, with a statistically significant change from baseline in MG-ADL and with a reduction of 4.2 points for inebilizumab versus 2.2 for placebo (P < .0001) at week 26 for the combined study population.
“You can see that the trend is actually going toward separation of the two groups after week 8 in the combined population,” said Nowak. Key secondary endpoints also showed statistically significant and clinically meaningful change from baseline compared with placebo.
This included a statistically significant change in QMG score inebilizumab compared with placebo for the combined population, a reduction of 4.8 versus 2.3 points, respectively, at week 26 (P = .0002).
In addition, both MG-ADL and QMG scores in the AChR+ subgroup were superior for inebilizumab versus placebo at week 26, with reductions of 4.2 versus 2.4, and 4.4 versus 2.0; P = .0015 and P = .0011, respectively.
In the MuSK+ subgroup, inebilizumab-treated patients had better MG-ADL scores than placebo-treated patients, with reductions of 3.9 versus 1.7 points, respectively, at week 26, although this difference did not meet statistical significance.
“There were no increased safety incidents in the inebilizumab-treated patients versus placebo, and a similar percentage of safety incidents in the AChR–positive and MuSK–positive groups. There were three deaths reported, all likely related to myasthenic crisis,” he said.
Nowak said that inebilizumab is “unique from the other currently FDA-approved medications for myasthenia gravis in that it’s targeting the upstream immunopathogenic mechanism of disease, specifically B cells — and B cells that are actually antibody-secreting cells.”
“It is targeting the factories of autoantibody production, whereas an FcRn antagonist, for example, is not targeting those factories but rather targeting what’s being produced — the immunoglobulins, IgGs in general,” he added.
Nowak said that what is particularly exciting about the drug is that the schedule is not very frequent. It begins with an initial IV infusion, followed by a second infusion 2 weeks later and a third infusion 6 months after that, so that patients are treated approximately every 6 months. This is in contrast to some other targeted therapies, where failing to address the underlying factors driving immunopathogenesis necessitates more regular and frequent medication administration.
New, Novel, Exciting
Commenting on the research, Neelam Goyal, MD, who chaired the session, said, “It’s definitely new, novel, interesting, exciting.”
Goyal, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, also noted that while B-cell depletion has shown some previous success in MG, it was with rituximab, a CD20 B-cell depleting agent.
She noted that unlike rituximab, which targets CD20, inebilizumab targets CD19, although both medications lead to B-cell depletion. Rituximab has proven effective for MUSK–positive MG, which accounts for approximately 5% of cases.
However, Goyal noted that the results for AChR–positive MG have been mixed — “the BeatMG trial was negative and the RINOMAX trial was positive. So, I think this is really interesting. It is exciting, and this drug is already on the market.”
She added that although inebilizumab is already US Food and Drug Administration–approved for the treatment of neuromyelitis optica, it still faces approval and indication hurdles for MG.
The future of this drug in the management algorithm for MG remains uncertain. Goyal noted that it’s “quite costly,” and although its benefits are evident — particularly for FcRn and complement inhibitors — some early data from chimeric antigen receptor T-cell therapy studies appear significantly more impressive.
Nowak disclosed research support from the National Institutes of Health, Genentech, Alexion Pharmaceuticals, argenx, Annexon Biosciences, Ra Pharmaceuticals (now UCB S.A.), the Myasthenia Gravis Foundation of America, Momenta Pharmaceuticals (now Janssen), Immunovant, Grifols, S.A., and Viela Bio, Horizon Therapeutics (now Amgen). Served as a consultant and advisor for Alexion Pharmaceuticals, argenx, Cabaletta Bio, Cour Pharmaceuticals, Ra Pharmaceuticals (now UCB S.A.), Immunovant, Momenta Pharmaceuticals (now Janssen), and Viela Bio (Horizon Therapeutics, now Amgen).
Goyal disclosed consultant, advisory, or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Amgen.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA — , new phase 3 data showed.
“Based on these results, we have demonstrated that targeting B cells, including the antibody-secreting cells, is beneficial, and there is likely a role for this kind of therapeutic strategy for patients with myasthenia gravis,” said senior investigator Richard Nowak, MD.
The findings were published and presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Largest Cohort of Muscle-Specific Kinase (MuSK) Antibody–Positive Disease
The Myasthenia Gravis INebilizumab Trial study enrolled 238 participants, 60.8% women, mean age 47.5 years, from 79 sites in 18 countries. The participants were divided into two cohorts: 190 acetylcholine receptor (AChR) autoantibody–positive patients and 48 MuSK autoantibody–positive patients.
“This is the largest enrolled cohort of MuSK antibody–positive disease in a placebo-controlled trial to date,” said Nowak, director of the Yale Myasthenia Gravis Clinic and associate professor of neurology at Yale School of Medicine, in New Haven, Connecticut.
Both groups had similar gMG duration (mean 6.7 and 5.2 years for AChR+ and MuSK+ patients, respectively) and disease severity based on Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) baseline score. In addition, more than 80% of participants were on a prednisone equivalent dose greater than 5 mg daily at study entry.
Participants were randomly assigned to receive intravenous (IV) inebilizumab or IV placebo for 52 weeks (AChR+ group) or 26 weeks (MuSK+ group). In addition, study participants who were taking corticosteroids were tapered down starting at week 4 to prednisone 5 mg per day by week 24.
The trial met its primary endpoint, with a statistically significant change from baseline in MG-ADL and with a reduction of 4.2 points for inebilizumab versus 2.2 for placebo (P < .0001) at week 26 for the combined study population.
“You can see that the trend is actually going toward separation of the two groups after week 8 in the combined population,” said Nowak. Key secondary endpoints also showed statistically significant and clinically meaningful change from baseline compared with placebo.
This included a statistically significant change in QMG score inebilizumab compared with placebo for the combined population, a reduction of 4.8 versus 2.3 points, respectively, at week 26 (P = .0002).
In addition, both MG-ADL and QMG scores in the AChR+ subgroup were superior for inebilizumab versus placebo at week 26, with reductions of 4.2 versus 2.4, and 4.4 versus 2.0; P = .0015 and P = .0011, respectively.
In the MuSK+ subgroup, inebilizumab-treated patients had better MG-ADL scores than placebo-treated patients, with reductions of 3.9 versus 1.7 points, respectively, at week 26, although this difference did not meet statistical significance.
“There were no increased safety incidents in the inebilizumab-treated patients versus placebo, and a similar percentage of safety incidents in the AChR–positive and MuSK–positive groups. There were three deaths reported, all likely related to myasthenic crisis,” he said.
Nowak said that inebilizumab is “unique from the other currently FDA-approved medications for myasthenia gravis in that it’s targeting the upstream immunopathogenic mechanism of disease, specifically B cells — and B cells that are actually antibody-secreting cells.”
“It is targeting the factories of autoantibody production, whereas an FcRn antagonist, for example, is not targeting those factories but rather targeting what’s being produced — the immunoglobulins, IgGs in general,” he added.
Nowak said that what is particularly exciting about the drug is that the schedule is not very frequent. It begins with an initial IV infusion, followed by a second infusion 2 weeks later and a third infusion 6 months after that, so that patients are treated approximately every 6 months. This is in contrast to some other targeted therapies, where failing to address the underlying factors driving immunopathogenesis necessitates more regular and frequent medication administration.
New, Novel, Exciting
Commenting on the research, Neelam Goyal, MD, who chaired the session, said, “It’s definitely new, novel, interesting, exciting.”
Goyal, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, also noted that while B-cell depletion has shown some previous success in MG, it was with rituximab, a CD20 B-cell depleting agent.
She noted that unlike rituximab, which targets CD20, inebilizumab targets CD19, although both medications lead to B-cell depletion. Rituximab has proven effective for MUSK–positive MG, which accounts for approximately 5% of cases.
However, Goyal noted that the results for AChR–positive MG have been mixed — “the BeatMG trial was negative and the RINOMAX trial was positive. So, I think this is really interesting. It is exciting, and this drug is already on the market.”
She added that although inebilizumab is already US Food and Drug Administration–approved for the treatment of neuromyelitis optica, it still faces approval and indication hurdles for MG.
The future of this drug in the management algorithm for MG remains uncertain. Goyal noted that it’s “quite costly,” and although its benefits are evident — particularly for FcRn and complement inhibitors — some early data from chimeric antigen receptor T-cell therapy studies appear significantly more impressive.
Nowak disclosed research support from the National Institutes of Health, Genentech, Alexion Pharmaceuticals, argenx, Annexon Biosciences, Ra Pharmaceuticals (now UCB S.A.), the Myasthenia Gravis Foundation of America, Momenta Pharmaceuticals (now Janssen), Immunovant, Grifols, S.A., and Viela Bio, Horizon Therapeutics (now Amgen). Served as a consultant and advisor for Alexion Pharmaceuticals, argenx, Cabaletta Bio, Cour Pharmaceuticals, Ra Pharmaceuticals (now UCB S.A.), Immunovant, Momenta Pharmaceuticals (now Janssen), and Viela Bio (Horizon Therapeutics, now Amgen).
Goyal disclosed consultant, advisory, or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Amgen.
A version of this article appeared on Medscape.com.
SAVANNAH, GEORGIA — , new phase 3 data showed.
“Based on these results, we have demonstrated that targeting B cells, including the antibody-secreting cells, is beneficial, and there is likely a role for this kind of therapeutic strategy for patients with myasthenia gravis,” said senior investigator Richard Nowak, MD.
The findings were published and presented at the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) 2024.
Largest Cohort of Muscle-Specific Kinase (MuSK) Antibody–Positive Disease
The Myasthenia Gravis INebilizumab Trial study enrolled 238 participants, 60.8% women, mean age 47.5 years, from 79 sites in 18 countries. The participants were divided into two cohorts: 190 acetylcholine receptor (AChR) autoantibody–positive patients and 48 MuSK autoantibody–positive patients.
“This is the largest enrolled cohort of MuSK antibody–positive disease in a placebo-controlled trial to date,” said Nowak, director of the Yale Myasthenia Gravis Clinic and associate professor of neurology at Yale School of Medicine, in New Haven, Connecticut.
Both groups had similar gMG duration (mean 6.7 and 5.2 years for AChR+ and MuSK+ patients, respectively) and disease severity based on Myasthenia Gravis Activities of Daily Living (MG-ADL) and Quantitative Myasthenia Gravis (QMG) baseline score. In addition, more than 80% of participants were on a prednisone equivalent dose greater than 5 mg daily at study entry.
Participants were randomly assigned to receive intravenous (IV) inebilizumab or IV placebo for 52 weeks (AChR+ group) or 26 weeks (MuSK+ group). In addition, study participants who were taking corticosteroids were tapered down starting at week 4 to prednisone 5 mg per day by week 24.
The trial met its primary endpoint, with a statistically significant change from baseline in MG-ADL and with a reduction of 4.2 points for inebilizumab versus 2.2 for placebo (P < .0001) at week 26 for the combined study population.
“You can see that the trend is actually going toward separation of the two groups after week 8 in the combined population,” said Nowak. Key secondary endpoints also showed statistically significant and clinically meaningful change from baseline compared with placebo.
This included a statistically significant change in QMG score inebilizumab compared with placebo for the combined population, a reduction of 4.8 versus 2.3 points, respectively, at week 26 (P = .0002).
In addition, both MG-ADL and QMG scores in the AChR+ subgroup were superior for inebilizumab versus placebo at week 26, with reductions of 4.2 versus 2.4, and 4.4 versus 2.0; P = .0015 and P = .0011, respectively.
In the MuSK+ subgroup, inebilizumab-treated patients had better MG-ADL scores than placebo-treated patients, with reductions of 3.9 versus 1.7 points, respectively, at week 26, although this difference did not meet statistical significance.
“There were no increased safety incidents in the inebilizumab-treated patients versus placebo, and a similar percentage of safety incidents in the AChR–positive and MuSK–positive groups. There were three deaths reported, all likely related to myasthenic crisis,” he said.
Nowak said that inebilizumab is “unique from the other currently FDA-approved medications for myasthenia gravis in that it’s targeting the upstream immunopathogenic mechanism of disease, specifically B cells — and B cells that are actually antibody-secreting cells.”
“It is targeting the factories of autoantibody production, whereas an FcRn antagonist, for example, is not targeting those factories but rather targeting what’s being produced — the immunoglobulins, IgGs in general,” he added.
Nowak said that what is particularly exciting about the drug is that the schedule is not very frequent. It begins with an initial IV infusion, followed by a second infusion 2 weeks later and a third infusion 6 months after that, so that patients are treated approximately every 6 months. This is in contrast to some other targeted therapies, where failing to address the underlying factors driving immunopathogenesis necessitates more regular and frequent medication administration.
New, Novel, Exciting
Commenting on the research, Neelam Goyal, MD, who chaired the session, said, “It’s definitely new, novel, interesting, exciting.”
Goyal, clinical professor of neurology and neurological sciences at Stanford University School of Medicine in Palo Alto, California, also noted that while B-cell depletion has shown some previous success in MG, it was with rituximab, a CD20 B-cell depleting agent.
She noted that unlike rituximab, which targets CD20, inebilizumab targets CD19, although both medications lead to B-cell depletion. Rituximab has proven effective for MUSK–positive MG, which accounts for approximately 5% of cases.
However, Goyal noted that the results for AChR–positive MG have been mixed — “the BeatMG trial was negative and the RINOMAX trial was positive. So, I think this is really interesting. It is exciting, and this drug is already on the market.”
She added that although inebilizumab is already US Food and Drug Administration–approved for the treatment of neuromyelitis optica, it still faces approval and indication hurdles for MG.
The future of this drug in the management algorithm for MG remains uncertain. Goyal noted that it’s “quite costly,” and although its benefits are evident — particularly for FcRn and complement inhibitors — some early data from chimeric antigen receptor T-cell therapy studies appear significantly more impressive.
Nowak disclosed research support from the National Institutes of Health, Genentech, Alexion Pharmaceuticals, argenx, Annexon Biosciences, Ra Pharmaceuticals (now UCB S.A.), the Myasthenia Gravis Foundation of America, Momenta Pharmaceuticals (now Janssen), Immunovant, Grifols, S.A., and Viela Bio, Horizon Therapeutics (now Amgen). Served as a consultant and advisor for Alexion Pharmaceuticals, argenx, Cabaletta Bio, Cour Pharmaceuticals, Ra Pharmaceuticals (now UCB S.A.), Immunovant, Momenta Pharmaceuticals (now Janssen), and Viela Bio (Horizon Therapeutics, now Amgen).
Goyal disclosed consultant, advisory, or grant support from argenx, UCB, Alexion, and Janssen. The study was funded by Amgen.
A version of this article appeared on Medscape.com.
FROM AANEM 2024
Myasthenia Gravis: Patient Choice, Cultural Change
Used appropriately, newer treatments can provide dramatic results faster and more safely than broad immunosuppressants. However, according to experts, payers’ willingness to cover costly new therapies remains a work in progress.
The availability of more effective treatments with fewer side effects has brought about a cultural shift, said James F. Howard, Jr, MD. “The physician’s goal now is for the patient to be symptom free with grade 1 or less adverse events. And patients are demanding freedom from all the side effects that our usual course of immune therapy produces.” Dr. Howard is professor of neurology, medicine and allied health and director of the Myasthenia Gravis Clinical Trials and Translational Research Program at the University of North Carolina at Chapel Hill.
The shift has been long in coming. Although myasthenia gravis was identified in the mid-1600s, it took more than 340 years to get the first drug approved specifically for the disorder.
Worldwide prevalence estimates vary widely, from less than 200,000 to 700,000 cases.1,2 Pathophysiologically, myasthenia gravis stems from autoimmune destruction of neuromuscular junctions (NMJs), which transmit motor neuron impulses to muscle fibers.1 Symptoms include variable skeletal muscle weakness that can range from mild and transient to life-threatening.
In approximately 80% of cases, autoimmune antibodies target the postsynaptic acetylcholine receptor (AChR). Additional autoimmune targets mainly include muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). However, around 10% of patients are seronegative, lacking autoantibodies detectable through conventional radioimmunoassays. Clinical disease does not always correspond with circulating antibody levels, and pathogenesis may require cooperation between multiple autoantibodies attacking the same target.3 Around 10% of MG cases are associated with thymomas.
Among myasthenia gravis treatments, immunosuppressants typically take 4-10 months to begin working and 18-36 months for maximum benefit. “Our new targeted therapies work within 1-2 weeks, with maximum improvement occurring somewhere between 8 and 12 weeks,” Dr. Howard said. Quick onset makes these drugs well suited for primary therapy in recalcitrant myasthenia gravis or as bridges to standard immunotherapy. Targeted drugs also appear to provide effective rescue therapy, although head-to-head studies are needed.
Complement Inhibition
In AChR antibody–positive myasthenia gravis, autoantibody binding with the postsynaptic AChR receptor activates complement to attack postsynaptic neuronal membrane. Complement inhibitors approved to date block activation of the terminal complement protein C5.
For many patients, complement inhibitors deliver dramatic results. Henry J. Kaminski, MD, said that the first patient for whom he prescribed a complement inhibitor outside a clinical trial went from being miserable to traveling internationally within a month. Dr. Kaminski is Meta A. Neumann Professor of Neurology at George Washington University, Washington, DC.
Eculizumab (Soliris, Alexion), earned Food and Drug Administration (FDA) approval for myasthenia gravis in 2017. Week 26 results in the phase 3 REGAIN trial showed no significant difference in Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores between treatment and placebo. However, said Dr. Howard, primary investigator on the study, the negative result was a statistical aberration stemming from the FDA’s requirement to use worst-rank analysis rather than absolute change scores. What got eculizumab approved were highly positive results in the overwhelming majority of secondary endpoints.4 Subsequently, the FDA had the manufacturer rewrite the package insert using common statistical methods, which yielded positive primary results.
Ravulizumab (Ultomiris, Alexion), approved for myasthenia gravis in 2022, reduces eculizumab’s twice-monthly intravenous dosing to every 2 months (after loading doses), with very similar efficacy. The newest complement inhibitor, zilucoplan (Zilbrysq, UCB), administered once daily subcutaneously, earned FDA approval in 2023. Daily subcutaneous dosing provides patient convenience, said Dr. Howard. Because the body does not clear this small molecule as it would a full-size antibody, it is the only complement inhibitor that can be combined with a fragment crystallizable neonatal receptor (FcRn) inhibitor.
FcRn Inhibition
The FcRn exists on the surface and intracellular vesicles of many cells, including B cells, but not T cells.5FcRn inhibitors block binding of circulating IgG antibodies to the FcRn, preventing their normal recycling, significantly reducing circulating antibodies within days of treatment.
Efgartigimod (Vyvgart, Argenx), earned FDA approval in intravenous form in 2021, followed by a subcutaneous formulation that includes hyaluronidase (Vyvgart Hytrulo) in 2023. Rozanolixizumab (Rystiggo, UCB) earned FDA approval for both AChR antibody–positive and MuSK antibody–positive myasthenia gravis in 2023.
Along with rapid response, said Dr. Howard, complement inhibitors and FcRn inhibitors offer a “hugely improved” side-effect profile. In phase 3 research, the most common side effects for both classes included headache, nausea, and diarrhea.4,6,7 Because complement inhibitors increase the risk of Neisseria infection, users require immunization against meningococcal infection (or concurrent antibiotic prophylaxis) while on complement inhibitors.
Insurance Issues
With many clinicians wondering which targeted therapy to choose for a particular patient, said Dr. Howard and Dr. Kaminski, the main obstacle to wider use of these treatments is payer attitudes and practices. “While many of us would like to see these drugs used earlier in the course of disease,” Dr. Howard explained, “there are numerous restrictions placed on the physician and the patient by whatever insurance the individual has.”
Dr. Kaminski said: “There’s a lot of variability among insurance companies regarding what is expected in terms of getting approval for a certain medication. It frustrates me, thinking this patient may do well with a complement inhibitor or an FcRn inhibitor, but it takes weeks to get them approved.”
Some of his patients have been approved for, and flourished on, complement inhibitors and FcRn inhibitors, he added, and then denied a second round of treatment. Dr. Kaminski said he does not know why these patients were denied, and every time he requests reevaluation, the decision is reversed. “That’s a significant time frame for me and my staff to manage.”
When asked what can be done to address high drug prices, Dr. Howard replied, “I have no idea. I’m not an advocate of high drug prices. But I don’t think people realize the cost of doing clinical trials, which is hundreds of millions of dollars, particularly in rare diseases.”
Presently, Dr. Howard said, FcRn inhibitors are used more frequently than complement inhibitors solely because of cost. Zilucoplan will be priced below existing complement inhibitors, although it is too soon to compare its price with those of FcRn inhibitors.
When eculizumab debuted, said Dr. Howard, it cost nearly $750,000 annually. “But if you look at the number of patients treated, the cost of the drug over this population is probably less than the cost for using a cholesterol-lowering agent to treat hyperlipidemia.”
An Institute for Clinical and Economic Review (ICER) report stated that eculizumab and efgartigimod should both cost less than $20,000 annually to meet commonly used cost-effectiveness thresholds.8 However, Dr. Howard said ICER used models based on common diseases and ignored the economic impact of patients’ losing fewer workdays and avoiding long-term immunosuppressant side effects such as diabetes and osteoporosis and related treatment costs. “We’ve got to start looking at total societal cost,” he said.
Leapfrogging Ahead
Not all the new drugs work in every indicated patient, Dr. Howard said. For example, up to 30% of patients do not respond to complement inhibitors. “We don’t understand why. It’s as if we have leapfrogged way ahead in terms of therapeutics, and now we have to go back and answer all the questions – the who, what, where, and why of an individual drug and its response in folks.”
In this climate, said Dr. Kaminski, heavy direct-to-consumer advertising of newer myasthenia gravis therapies creates complications. “My patients are highly excited to see, ‘that’s my disease being advertised on Jeopardy.’ ” Many patients are frustrated with the general lack of awareness regarding myasthenia gravis, he added. “But then I’ve had patients who clearly would never qualify for a certain medication getting mailings to their homes.”
Dr. Howard countered that broader awareness of myasthenia gravis can only help. “There’s increasing recognition of the disease, not only by patients, but to some extent, by the treating clinician. Patients are coming to our offices and saying, ‘am I a candidate for this new drug?’ It’s the responsibility of the clinician to decide.”
Individual physicians’ practice patterns vary greatly, said Dr. Kaminski, and very little quantitative data exist here. But based on personal communications, academic-center neurologists tend to use targeted treatments on patients who have failed conventional treatments.
Conversely, Dr. Howard said that, because community physicians rarely see myasthenia gravis, and targeted treatments remain relatively new, many of these providers rely on prednisone, azathioprine, and mycophenolate mofetil.
B-Cell Blockers in Development
Overall, said Dr. Howard, the field of myasthenia gravis treatment development is “very rich. And pharma’s interest in myasthenia has taken off like a rocket. It’s exceptionally gratifying to those of us who take care of these patients whose life is miserable” because of adverse effects and/or nonresponse to current drugs.
“In myasthenia,” added Dr. Kaminski, “we know that T cells are promoting the activity of these auto-reactive B cells.” Many drugs currently in phase 2 or 3 development aim to eliminate B cells or signaling between T and B cells, he said. “That’s where most of the drug development is.”
Leading candidates include telitacicept (Tai’ai, RemeGen), which is both a B-lymphocyte stimulator and a proliferation-inducing ligand. A phase 3 trial (NCT05737160) is ongoing, with primary completion expected in late 2026. A second phase 3 trial (NCT06456580) recently began enrolling. Dr. Howard said that, although early results warranted phase 3 analysis, telitacicept’s phase 2 trial was open label and lacked a placebo group.9 The latter is a critical concern because placebo response rates in myasthenia gravis trials average 35%-40%.
Combined with standard care, the FcRn inhibitor nipocalimab (Johnson & Johnson) enabled patients with AChR, MuSK, and/or LRP4 autoantibodies to improve by 4.70 points on the MG-ADL vs 3.25 points for placebo (P = .002) over 24 weeks in phase 3.10All FcRn inhibitors in development can broadly reduce autoantibody levels, said Dr. Howard. “But what role they will play in myasthenia gravis when they’re several years behind leaders in the field in terms of capturing market remains to be seen.”
Additionally, batoclimab (Immunovant/Harbour BioMed) showed positive topline results in phase 3, and an elevated rate of hypercholesterolemia in treated patients that was transient and consistent with previous research.11 Subsequent to efgartigimod, Dr. Howard said, FcRn inhibitors are full-size antibodies. “I believe that contributes to the adverse events that we see. Efgartigimod is a small FcRn fragment. That’s why it’s a cleaner drug, if you will.”
FcRn inhibitors require periodic retreatment. For example, said Dr. Howard, the ADAPT phase 3 trial of efgartigimod, on which he was lead investigator, employed a cyclic dosing schedule – 4 weeks’ treatment, then observation until patients needed retreatment — because patients demanded it.12 In clinical practice, some patients have gone more than 25 weeks before needing retreatment. One of his patients went beyond 40 weeks. “Others only get around 6-9 weeks. So patient choice again enters the decision-making process.”
Rituximab targets the CD20 protein on B cells nonspecifically, producing general immunosuppression. “That’s problematic in producing significant immunosuppression,” said Dr. Kaminski. Nevertheless, he said, rituximab is very effective for most patients with MuSK-specific MG, and its application to this indication has revealed differences between the MuSK subtype and AChR antibody–positive myasthenia. Specifically, MuSK antibody–positive patients have short-lived plasmablasts, which rituximab eliminates.13
Conversely, said Dr. Kaminski, patients with AChR antibody-positive myasthenia, especially long-term, likely have long-lived plasmablasts producing antibodies. This fact, and these patients’ lack of CD20, likely explain their poor response to rituximab.
A phase 3 trial (NCT04524273) of the CD19 blocker inebilizumab (Uplinza, Amgen) reached primary completion in May. Dr. Howard said that if topline results (unreleased at press time) prove positive, inebilizumab could replace rituximab in MG — provided payers do not reject inebilizumab because of cost.
Packed Early-Development Pipeline
Regarding early-stage projects, said Dr. Howard, the pipeline is packed with compounds that target various aspects of the immune system. “The real question with those is, what’s going to be the side effect profile? All of the trials are very early. We need bigger trials with much longer observation for safety, durability, and degree of efficacy.”
The next potential B cell–targeting game changer, he said, is chimeric antigen receptor (CAR) T cell–based therapy. In a phase 2b trial of Descartes-08 (Cartesian Therapeutics), 71% of treated patients experienced clinically meaningful improvement in MG Composite score at 3 months vs 25% for placebo.14
In early clinical trials, said Dr. Howard, patients treated with Descartes-08 — which uses autologous mRNA to target B-cell maturation antigen — have shown “exceptional improvement” lasting 20 or more months. Because the drug is not ingrained permanently into the genome, Descartes-08 avoids potentially severe side effects of DNA-targeting CAR T candidates. Dr. Howard hopes a phase 3 trial will commence around January 2025.
The tolerance approach exemplified by CNP-106 (COUR Pharmaceuticals) and a myasthenia gravis tolerogen (Toleranzia) seeks to prevent the immune system from recognizing and reacting to the NMJ abnormalities that produce myasthenia gravis, potentially providing a cure. “We look forward to those trials as they come online in the next 1-2 years,” said Dr. Howard.
Unmet Needs
Historically, neurologists believed that all myasthenia gravis symptoms stemmed from muscle fatigue — the more active the muscle, the weaker it gets. However, said Dr. Kaminski, some patients might lack measurable weakness but still complain of fatigue.
Elevated levels of cytokines such as interleukin (IL)–6 or IL-17 also can produce fatigue, he noted. “With the drugs we’re using, certainly the new ones, we’re not specifically targeting this fatigue phenomenon, which has been studied in a very limited fashion.”
In the RAISE-XT zilucoplan trial, participants experienced significant improvement in fatigue scores for up to 60 weeks.15 Although zilucoplan does not address fatigue directly, said Dr. Howard, improving myasthenia gravis overall helps reduce fatigue.
The Myasthenia Gravis Symptoms Patient Reported Outcome (MG Symptoms PRO), which Dr. Kaminski helped develop, includes questions designed to distinguish muscular fatigue from overall physical fatigue.16 “I’m very interested in some of the information that’s coming out on long COVID and its effect on muscle,” Dr. Kaminski added. “We might be able to learn from there that there’s still some pathology going on beyond the neuromuscular junction.”
What the field desperately needs, said Dr. Howard, are biomarkers to identify which patients will and will not respond to certain therapeutics. “We’re not there yet.” Such biomarkers are at least 3-7 years from becoming clinical reality.
Promising antibody-independent serum markers include circulating microRNAs. For example, miRNA-150-5p and miRNA-21-5p are elevated in generalized AChR-positive myasthenia gravis and early-onset myasthenia gravis (occurring before age 50) and decline after immunosuppression and thymectomy.17
Among diagnostic modalities for patients with seronegative myasthenia gravis, said Dr. Kaminski, single-fiber EMG is the most sensitive, at approximately 95%. “It’s not perfect.” Moreover, he said, performing this test accurately requires a highly experienced expert, which many treatment centers lack.
Presently, added Dr. Kaminski, orbital MRI is neither specific nor sensitive enough to be clinically useful. “One needs to be careful with these specialized tests that are published from the best laboratory in the world that does the test, and does it repetitively.” As the search for effective myasthenia gravis biomarkers continues, avoiding false-positive results is as important as avoiding false negatives.
References
1. Bubuioc AM et al. J Med Life. 2021 Jan-Mar;14(1):7-16. doi: 10.25122/jml-2020-0145.
2. Deenen JC et al. J Neuromuscul Dis. 2015;2(1):73-85. doi: 10.3233/JND-140045.
3. Kaminski HJ et al. J Clin Invest. 2024 Jun 17;134(12):e179742. doi: 10.1172/JCI179742.
4. Howard JF Jr et al. Lancet Neurol. 2017 Dec;16(12):976-986. doi: 10.1016/S1474-4422(17)30369-1.
5. Huda R. Front Immunol. 2020 Feb 21:11:240. doi: 10.3389/fimmu.2020.00240.
6. Howard JF Jr et al. Lancet Neurol. 2023 May;22(5):395-406. doi: 10.1016/S1474-4422(23)00080-7.
7. Vu T et al. NEJM Evid. 2022 May;1(5):EVIDoa2100066. doi: 10.1056/EVIDoa2100066.
8. Tice JA et al. October 20, 2021. https://icer.org/assessment/myasthenia-gravis/.
9. Yin J et al. Eur J Neurol. 2024 Aug;31(8):e16322. doi: 10.1111/ene.16322.
10. Antozzi C et al. EAN 2024, Abstract EPR-116. https://www.neurology.org/doi/10.1212/WNL.0000000000203660.
11. Yan C et al. JAMA Neurol. 2024 Mar 4;81(4):336-345. doi: 10.1001/jamaneurol.2024.0044.
12. Howard JF Jr et al. Lancet Neurol. 2021 Jul;20(7):526-536. doi: 10.1016/S1474-4422(21)00159-9.
13. Stathopoulos P et al. JCI Insight. 2017 Sep 7;2(17):e94263. doi: 10.1172/jci.insight.94263.
14. Cartesian Therapeutics. Cartesian Therapeutics announces positive topline results from phase 2b trial of Descartes-08 in patients with myasthenia gravis. 2024 Jul 2. https://ir.cartesiantherapeutics.com/news-releases/news-release-details/cartesian-therapeutics-announces-positive-topline-results-phase.
15. Howard JF Jr et al. Ther Adv Neurol Disord. 2024 Apr 17:17:17562864241243186. doi: 10.1177/17562864241243186.
16. Cleanthous S et al. Orphanet J Rare Dis. 2021 Oct 30;16(1):457. doi: 10.1186/s13023-021-02064-0.
17. Sabre L et al. Front Immunol. 2020 Mar 4:11:213. doi: 10.3389/fimmu.2020.00213.
Used appropriately, newer treatments can provide dramatic results faster and more safely than broad immunosuppressants. However, according to experts, payers’ willingness to cover costly new therapies remains a work in progress.
The availability of more effective treatments with fewer side effects has brought about a cultural shift, said James F. Howard, Jr, MD. “The physician’s goal now is for the patient to be symptom free with grade 1 or less adverse events. And patients are demanding freedom from all the side effects that our usual course of immune therapy produces.” Dr. Howard is professor of neurology, medicine and allied health and director of the Myasthenia Gravis Clinical Trials and Translational Research Program at the University of North Carolina at Chapel Hill.
The shift has been long in coming. Although myasthenia gravis was identified in the mid-1600s, it took more than 340 years to get the first drug approved specifically for the disorder.
Worldwide prevalence estimates vary widely, from less than 200,000 to 700,000 cases.1,2 Pathophysiologically, myasthenia gravis stems from autoimmune destruction of neuromuscular junctions (NMJs), which transmit motor neuron impulses to muscle fibers.1 Symptoms include variable skeletal muscle weakness that can range from mild and transient to life-threatening.
In approximately 80% of cases, autoimmune antibodies target the postsynaptic acetylcholine receptor (AChR). Additional autoimmune targets mainly include muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). However, around 10% of patients are seronegative, lacking autoantibodies detectable through conventional radioimmunoassays. Clinical disease does not always correspond with circulating antibody levels, and pathogenesis may require cooperation between multiple autoantibodies attacking the same target.3 Around 10% of MG cases are associated with thymomas.
Among myasthenia gravis treatments, immunosuppressants typically take 4-10 months to begin working and 18-36 months for maximum benefit. “Our new targeted therapies work within 1-2 weeks, with maximum improvement occurring somewhere between 8 and 12 weeks,” Dr. Howard said. Quick onset makes these drugs well suited for primary therapy in recalcitrant myasthenia gravis or as bridges to standard immunotherapy. Targeted drugs also appear to provide effective rescue therapy, although head-to-head studies are needed.
Complement Inhibition
In AChR antibody–positive myasthenia gravis, autoantibody binding with the postsynaptic AChR receptor activates complement to attack postsynaptic neuronal membrane. Complement inhibitors approved to date block activation of the terminal complement protein C5.
For many patients, complement inhibitors deliver dramatic results. Henry J. Kaminski, MD, said that the first patient for whom he prescribed a complement inhibitor outside a clinical trial went from being miserable to traveling internationally within a month. Dr. Kaminski is Meta A. Neumann Professor of Neurology at George Washington University, Washington, DC.
Eculizumab (Soliris, Alexion), earned Food and Drug Administration (FDA) approval for myasthenia gravis in 2017. Week 26 results in the phase 3 REGAIN trial showed no significant difference in Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores between treatment and placebo. However, said Dr. Howard, primary investigator on the study, the negative result was a statistical aberration stemming from the FDA’s requirement to use worst-rank analysis rather than absolute change scores. What got eculizumab approved were highly positive results in the overwhelming majority of secondary endpoints.4 Subsequently, the FDA had the manufacturer rewrite the package insert using common statistical methods, which yielded positive primary results.
Ravulizumab (Ultomiris, Alexion), approved for myasthenia gravis in 2022, reduces eculizumab’s twice-monthly intravenous dosing to every 2 months (after loading doses), with very similar efficacy. The newest complement inhibitor, zilucoplan (Zilbrysq, UCB), administered once daily subcutaneously, earned FDA approval in 2023. Daily subcutaneous dosing provides patient convenience, said Dr. Howard. Because the body does not clear this small molecule as it would a full-size antibody, it is the only complement inhibitor that can be combined with a fragment crystallizable neonatal receptor (FcRn) inhibitor.
FcRn Inhibition
The FcRn exists on the surface and intracellular vesicles of many cells, including B cells, but not T cells.5FcRn inhibitors block binding of circulating IgG antibodies to the FcRn, preventing their normal recycling, significantly reducing circulating antibodies within days of treatment.
Efgartigimod (Vyvgart, Argenx), earned FDA approval in intravenous form in 2021, followed by a subcutaneous formulation that includes hyaluronidase (Vyvgart Hytrulo) in 2023. Rozanolixizumab (Rystiggo, UCB) earned FDA approval for both AChR antibody–positive and MuSK antibody–positive myasthenia gravis in 2023.
Along with rapid response, said Dr. Howard, complement inhibitors and FcRn inhibitors offer a “hugely improved” side-effect profile. In phase 3 research, the most common side effects for both classes included headache, nausea, and diarrhea.4,6,7 Because complement inhibitors increase the risk of Neisseria infection, users require immunization against meningococcal infection (or concurrent antibiotic prophylaxis) while on complement inhibitors.
Insurance Issues
With many clinicians wondering which targeted therapy to choose for a particular patient, said Dr. Howard and Dr. Kaminski, the main obstacle to wider use of these treatments is payer attitudes and practices. “While many of us would like to see these drugs used earlier in the course of disease,” Dr. Howard explained, “there are numerous restrictions placed on the physician and the patient by whatever insurance the individual has.”
Dr. Kaminski said: “There’s a lot of variability among insurance companies regarding what is expected in terms of getting approval for a certain medication. It frustrates me, thinking this patient may do well with a complement inhibitor or an FcRn inhibitor, but it takes weeks to get them approved.”
Some of his patients have been approved for, and flourished on, complement inhibitors and FcRn inhibitors, he added, and then denied a second round of treatment. Dr. Kaminski said he does not know why these patients were denied, and every time he requests reevaluation, the decision is reversed. “That’s a significant time frame for me and my staff to manage.”
When asked what can be done to address high drug prices, Dr. Howard replied, “I have no idea. I’m not an advocate of high drug prices. But I don’t think people realize the cost of doing clinical trials, which is hundreds of millions of dollars, particularly in rare diseases.”
Presently, Dr. Howard said, FcRn inhibitors are used more frequently than complement inhibitors solely because of cost. Zilucoplan will be priced below existing complement inhibitors, although it is too soon to compare its price with those of FcRn inhibitors.
When eculizumab debuted, said Dr. Howard, it cost nearly $750,000 annually. “But if you look at the number of patients treated, the cost of the drug over this population is probably less than the cost for using a cholesterol-lowering agent to treat hyperlipidemia.”
An Institute for Clinical and Economic Review (ICER) report stated that eculizumab and efgartigimod should both cost less than $20,000 annually to meet commonly used cost-effectiveness thresholds.8 However, Dr. Howard said ICER used models based on common diseases and ignored the economic impact of patients’ losing fewer workdays and avoiding long-term immunosuppressant side effects such as diabetes and osteoporosis and related treatment costs. “We’ve got to start looking at total societal cost,” he said.
Leapfrogging Ahead
Not all the new drugs work in every indicated patient, Dr. Howard said. For example, up to 30% of patients do not respond to complement inhibitors. “We don’t understand why. It’s as if we have leapfrogged way ahead in terms of therapeutics, and now we have to go back and answer all the questions – the who, what, where, and why of an individual drug and its response in folks.”
In this climate, said Dr. Kaminski, heavy direct-to-consumer advertising of newer myasthenia gravis therapies creates complications. “My patients are highly excited to see, ‘that’s my disease being advertised on Jeopardy.’ ” Many patients are frustrated with the general lack of awareness regarding myasthenia gravis, he added. “But then I’ve had patients who clearly would never qualify for a certain medication getting mailings to their homes.”
Dr. Howard countered that broader awareness of myasthenia gravis can only help. “There’s increasing recognition of the disease, not only by patients, but to some extent, by the treating clinician. Patients are coming to our offices and saying, ‘am I a candidate for this new drug?’ It’s the responsibility of the clinician to decide.”
Individual physicians’ practice patterns vary greatly, said Dr. Kaminski, and very little quantitative data exist here. But based on personal communications, academic-center neurologists tend to use targeted treatments on patients who have failed conventional treatments.
Conversely, Dr. Howard said that, because community physicians rarely see myasthenia gravis, and targeted treatments remain relatively new, many of these providers rely on prednisone, azathioprine, and mycophenolate mofetil.
B-Cell Blockers in Development
Overall, said Dr. Howard, the field of myasthenia gravis treatment development is “very rich. And pharma’s interest in myasthenia has taken off like a rocket. It’s exceptionally gratifying to those of us who take care of these patients whose life is miserable” because of adverse effects and/or nonresponse to current drugs.
“In myasthenia,” added Dr. Kaminski, “we know that T cells are promoting the activity of these auto-reactive B cells.” Many drugs currently in phase 2 or 3 development aim to eliminate B cells or signaling between T and B cells, he said. “That’s where most of the drug development is.”
Leading candidates include telitacicept (Tai’ai, RemeGen), which is both a B-lymphocyte stimulator and a proliferation-inducing ligand. A phase 3 trial (NCT05737160) is ongoing, with primary completion expected in late 2026. A second phase 3 trial (NCT06456580) recently began enrolling. Dr. Howard said that, although early results warranted phase 3 analysis, telitacicept’s phase 2 trial was open label and lacked a placebo group.9 The latter is a critical concern because placebo response rates in myasthenia gravis trials average 35%-40%.
Combined with standard care, the FcRn inhibitor nipocalimab (Johnson & Johnson) enabled patients with AChR, MuSK, and/or LRP4 autoantibodies to improve by 4.70 points on the MG-ADL vs 3.25 points for placebo (P = .002) over 24 weeks in phase 3.10All FcRn inhibitors in development can broadly reduce autoantibody levels, said Dr. Howard. “But what role they will play in myasthenia gravis when they’re several years behind leaders in the field in terms of capturing market remains to be seen.”
Additionally, batoclimab (Immunovant/Harbour BioMed) showed positive topline results in phase 3, and an elevated rate of hypercholesterolemia in treated patients that was transient and consistent with previous research.11 Subsequent to efgartigimod, Dr. Howard said, FcRn inhibitors are full-size antibodies. “I believe that contributes to the adverse events that we see. Efgartigimod is a small FcRn fragment. That’s why it’s a cleaner drug, if you will.”
FcRn inhibitors require periodic retreatment. For example, said Dr. Howard, the ADAPT phase 3 trial of efgartigimod, on which he was lead investigator, employed a cyclic dosing schedule – 4 weeks’ treatment, then observation until patients needed retreatment — because patients demanded it.12 In clinical practice, some patients have gone more than 25 weeks before needing retreatment. One of his patients went beyond 40 weeks. “Others only get around 6-9 weeks. So patient choice again enters the decision-making process.”
Rituximab targets the CD20 protein on B cells nonspecifically, producing general immunosuppression. “That’s problematic in producing significant immunosuppression,” said Dr. Kaminski. Nevertheless, he said, rituximab is very effective for most patients with MuSK-specific MG, and its application to this indication has revealed differences between the MuSK subtype and AChR antibody–positive myasthenia. Specifically, MuSK antibody–positive patients have short-lived plasmablasts, which rituximab eliminates.13
Conversely, said Dr. Kaminski, patients with AChR antibody-positive myasthenia, especially long-term, likely have long-lived plasmablasts producing antibodies. This fact, and these patients’ lack of CD20, likely explain their poor response to rituximab.
A phase 3 trial (NCT04524273) of the CD19 blocker inebilizumab (Uplinza, Amgen) reached primary completion in May. Dr. Howard said that if topline results (unreleased at press time) prove positive, inebilizumab could replace rituximab in MG — provided payers do not reject inebilizumab because of cost.
Packed Early-Development Pipeline
Regarding early-stage projects, said Dr. Howard, the pipeline is packed with compounds that target various aspects of the immune system. “The real question with those is, what’s going to be the side effect profile? All of the trials are very early. We need bigger trials with much longer observation for safety, durability, and degree of efficacy.”
The next potential B cell–targeting game changer, he said, is chimeric antigen receptor (CAR) T cell–based therapy. In a phase 2b trial of Descartes-08 (Cartesian Therapeutics), 71% of treated patients experienced clinically meaningful improvement in MG Composite score at 3 months vs 25% for placebo.14
In early clinical trials, said Dr. Howard, patients treated with Descartes-08 — which uses autologous mRNA to target B-cell maturation antigen — have shown “exceptional improvement” lasting 20 or more months. Because the drug is not ingrained permanently into the genome, Descartes-08 avoids potentially severe side effects of DNA-targeting CAR T candidates. Dr. Howard hopes a phase 3 trial will commence around January 2025.
The tolerance approach exemplified by CNP-106 (COUR Pharmaceuticals) and a myasthenia gravis tolerogen (Toleranzia) seeks to prevent the immune system from recognizing and reacting to the NMJ abnormalities that produce myasthenia gravis, potentially providing a cure. “We look forward to those trials as they come online in the next 1-2 years,” said Dr. Howard.
Unmet Needs
Historically, neurologists believed that all myasthenia gravis symptoms stemmed from muscle fatigue — the more active the muscle, the weaker it gets. However, said Dr. Kaminski, some patients might lack measurable weakness but still complain of fatigue.
Elevated levels of cytokines such as interleukin (IL)–6 or IL-17 also can produce fatigue, he noted. “With the drugs we’re using, certainly the new ones, we’re not specifically targeting this fatigue phenomenon, which has been studied in a very limited fashion.”
In the RAISE-XT zilucoplan trial, participants experienced significant improvement in fatigue scores for up to 60 weeks.15 Although zilucoplan does not address fatigue directly, said Dr. Howard, improving myasthenia gravis overall helps reduce fatigue.
The Myasthenia Gravis Symptoms Patient Reported Outcome (MG Symptoms PRO), which Dr. Kaminski helped develop, includes questions designed to distinguish muscular fatigue from overall physical fatigue.16 “I’m very interested in some of the information that’s coming out on long COVID and its effect on muscle,” Dr. Kaminski added. “We might be able to learn from there that there’s still some pathology going on beyond the neuromuscular junction.”
What the field desperately needs, said Dr. Howard, are biomarkers to identify which patients will and will not respond to certain therapeutics. “We’re not there yet.” Such biomarkers are at least 3-7 years from becoming clinical reality.
Promising antibody-independent serum markers include circulating microRNAs. For example, miRNA-150-5p and miRNA-21-5p are elevated in generalized AChR-positive myasthenia gravis and early-onset myasthenia gravis (occurring before age 50) and decline after immunosuppression and thymectomy.17
Among diagnostic modalities for patients with seronegative myasthenia gravis, said Dr. Kaminski, single-fiber EMG is the most sensitive, at approximately 95%. “It’s not perfect.” Moreover, he said, performing this test accurately requires a highly experienced expert, which many treatment centers lack.
Presently, added Dr. Kaminski, orbital MRI is neither specific nor sensitive enough to be clinically useful. “One needs to be careful with these specialized tests that are published from the best laboratory in the world that does the test, and does it repetitively.” As the search for effective myasthenia gravis biomarkers continues, avoiding false-positive results is as important as avoiding false negatives.
References
1. Bubuioc AM et al. J Med Life. 2021 Jan-Mar;14(1):7-16. doi: 10.25122/jml-2020-0145.
2. Deenen JC et al. J Neuromuscul Dis. 2015;2(1):73-85. doi: 10.3233/JND-140045.
3. Kaminski HJ et al. J Clin Invest. 2024 Jun 17;134(12):e179742. doi: 10.1172/JCI179742.
4. Howard JF Jr et al. Lancet Neurol. 2017 Dec;16(12):976-986. doi: 10.1016/S1474-4422(17)30369-1.
5. Huda R. Front Immunol. 2020 Feb 21:11:240. doi: 10.3389/fimmu.2020.00240.
6. Howard JF Jr et al. Lancet Neurol. 2023 May;22(5):395-406. doi: 10.1016/S1474-4422(23)00080-7.
7. Vu T et al. NEJM Evid. 2022 May;1(5):EVIDoa2100066. doi: 10.1056/EVIDoa2100066.
8. Tice JA et al. October 20, 2021. https://icer.org/assessment/myasthenia-gravis/.
9. Yin J et al. Eur J Neurol. 2024 Aug;31(8):e16322. doi: 10.1111/ene.16322.
10. Antozzi C et al. EAN 2024, Abstract EPR-116. https://www.neurology.org/doi/10.1212/WNL.0000000000203660.
11. Yan C et al. JAMA Neurol. 2024 Mar 4;81(4):336-345. doi: 10.1001/jamaneurol.2024.0044.
12. Howard JF Jr et al. Lancet Neurol. 2021 Jul;20(7):526-536. doi: 10.1016/S1474-4422(21)00159-9.
13. Stathopoulos P et al. JCI Insight. 2017 Sep 7;2(17):e94263. doi: 10.1172/jci.insight.94263.
14. Cartesian Therapeutics. Cartesian Therapeutics announces positive topline results from phase 2b trial of Descartes-08 in patients with myasthenia gravis. 2024 Jul 2. https://ir.cartesiantherapeutics.com/news-releases/news-release-details/cartesian-therapeutics-announces-positive-topline-results-phase.
15. Howard JF Jr et al. Ther Adv Neurol Disord. 2024 Apr 17:17:17562864241243186. doi: 10.1177/17562864241243186.
16. Cleanthous S et al. Orphanet J Rare Dis. 2021 Oct 30;16(1):457. doi: 10.1186/s13023-021-02064-0.
17. Sabre L et al. Front Immunol. 2020 Mar 4:11:213. doi: 10.3389/fimmu.2020.00213.
Used appropriately, newer treatments can provide dramatic results faster and more safely than broad immunosuppressants. However, according to experts, payers’ willingness to cover costly new therapies remains a work in progress.
The availability of more effective treatments with fewer side effects has brought about a cultural shift, said James F. Howard, Jr, MD. “The physician’s goal now is for the patient to be symptom free with grade 1 or less adverse events. And patients are demanding freedom from all the side effects that our usual course of immune therapy produces.” Dr. Howard is professor of neurology, medicine and allied health and director of the Myasthenia Gravis Clinical Trials and Translational Research Program at the University of North Carolina at Chapel Hill.
The shift has been long in coming. Although myasthenia gravis was identified in the mid-1600s, it took more than 340 years to get the first drug approved specifically for the disorder.
Worldwide prevalence estimates vary widely, from less than 200,000 to 700,000 cases.1,2 Pathophysiologically, myasthenia gravis stems from autoimmune destruction of neuromuscular junctions (NMJs), which transmit motor neuron impulses to muscle fibers.1 Symptoms include variable skeletal muscle weakness that can range from mild and transient to life-threatening.
In approximately 80% of cases, autoimmune antibodies target the postsynaptic acetylcholine receptor (AChR). Additional autoimmune targets mainly include muscle-specific kinase (MuSK) and lipoprotein receptor-related protein 4 (LRP4). However, around 10% of patients are seronegative, lacking autoantibodies detectable through conventional radioimmunoassays. Clinical disease does not always correspond with circulating antibody levels, and pathogenesis may require cooperation between multiple autoantibodies attacking the same target.3 Around 10% of MG cases are associated with thymomas.
Among myasthenia gravis treatments, immunosuppressants typically take 4-10 months to begin working and 18-36 months for maximum benefit. “Our new targeted therapies work within 1-2 weeks, with maximum improvement occurring somewhere between 8 and 12 weeks,” Dr. Howard said. Quick onset makes these drugs well suited for primary therapy in recalcitrant myasthenia gravis or as bridges to standard immunotherapy. Targeted drugs also appear to provide effective rescue therapy, although head-to-head studies are needed.
Complement Inhibition
In AChR antibody–positive myasthenia gravis, autoantibody binding with the postsynaptic AChR receptor activates complement to attack postsynaptic neuronal membrane. Complement inhibitors approved to date block activation of the terminal complement protein C5.
For many patients, complement inhibitors deliver dramatic results. Henry J. Kaminski, MD, said that the first patient for whom he prescribed a complement inhibitor outside a clinical trial went from being miserable to traveling internationally within a month. Dr. Kaminski is Meta A. Neumann Professor of Neurology at George Washington University, Washington, DC.
Eculizumab (Soliris, Alexion), earned Food and Drug Administration (FDA) approval for myasthenia gravis in 2017. Week 26 results in the phase 3 REGAIN trial showed no significant difference in Myasthenia Gravis–Activities of Daily Living (MG-ADL) scores between treatment and placebo. However, said Dr. Howard, primary investigator on the study, the negative result was a statistical aberration stemming from the FDA’s requirement to use worst-rank analysis rather than absolute change scores. What got eculizumab approved were highly positive results in the overwhelming majority of secondary endpoints.4 Subsequently, the FDA had the manufacturer rewrite the package insert using common statistical methods, which yielded positive primary results.
Ravulizumab (Ultomiris, Alexion), approved for myasthenia gravis in 2022, reduces eculizumab’s twice-monthly intravenous dosing to every 2 months (after loading doses), with very similar efficacy. The newest complement inhibitor, zilucoplan (Zilbrysq, UCB), administered once daily subcutaneously, earned FDA approval in 2023. Daily subcutaneous dosing provides patient convenience, said Dr. Howard. Because the body does not clear this small molecule as it would a full-size antibody, it is the only complement inhibitor that can be combined with a fragment crystallizable neonatal receptor (FcRn) inhibitor.
FcRn Inhibition
The FcRn exists on the surface and intracellular vesicles of many cells, including B cells, but not T cells.5FcRn inhibitors block binding of circulating IgG antibodies to the FcRn, preventing their normal recycling, significantly reducing circulating antibodies within days of treatment.
Efgartigimod (Vyvgart, Argenx), earned FDA approval in intravenous form in 2021, followed by a subcutaneous formulation that includes hyaluronidase (Vyvgart Hytrulo) in 2023. Rozanolixizumab (Rystiggo, UCB) earned FDA approval for both AChR antibody–positive and MuSK antibody–positive myasthenia gravis in 2023.
Along with rapid response, said Dr. Howard, complement inhibitors and FcRn inhibitors offer a “hugely improved” side-effect profile. In phase 3 research, the most common side effects for both classes included headache, nausea, and diarrhea.4,6,7 Because complement inhibitors increase the risk of Neisseria infection, users require immunization against meningococcal infection (or concurrent antibiotic prophylaxis) while on complement inhibitors.
Insurance Issues
With many clinicians wondering which targeted therapy to choose for a particular patient, said Dr. Howard and Dr. Kaminski, the main obstacle to wider use of these treatments is payer attitudes and practices. “While many of us would like to see these drugs used earlier in the course of disease,” Dr. Howard explained, “there are numerous restrictions placed on the physician and the patient by whatever insurance the individual has.”
Dr. Kaminski said: “There’s a lot of variability among insurance companies regarding what is expected in terms of getting approval for a certain medication. It frustrates me, thinking this patient may do well with a complement inhibitor or an FcRn inhibitor, but it takes weeks to get them approved.”
Some of his patients have been approved for, and flourished on, complement inhibitors and FcRn inhibitors, he added, and then denied a second round of treatment. Dr. Kaminski said he does not know why these patients were denied, and every time he requests reevaluation, the decision is reversed. “That’s a significant time frame for me and my staff to manage.”
When asked what can be done to address high drug prices, Dr. Howard replied, “I have no idea. I’m not an advocate of high drug prices. But I don’t think people realize the cost of doing clinical trials, which is hundreds of millions of dollars, particularly in rare diseases.”
Presently, Dr. Howard said, FcRn inhibitors are used more frequently than complement inhibitors solely because of cost. Zilucoplan will be priced below existing complement inhibitors, although it is too soon to compare its price with those of FcRn inhibitors.
When eculizumab debuted, said Dr. Howard, it cost nearly $750,000 annually. “But if you look at the number of patients treated, the cost of the drug over this population is probably less than the cost for using a cholesterol-lowering agent to treat hyperlipidemia.”
An Institute for Clinical and Economic Review (ICER) report stated that eculizumab and efgartigimod should both cost less than $20,000 annually to meet commonly used cost-effectiveness thresholds.8 However, Dr. Howard said ICER used models based on common diseases and ignored the economic impact of patients’ losing fewer workdays and avoiding long-term immunosuppressant side effects such as diabetes and osteoporosis and related treatment costs. “We’ve got to start looking at total societal cost,” he said.
Leapfrogging Ahead
Not all the new drugs work in every indicated patient, Dr. Howard said. For example, up to 30% of patients do not respond to complement inhibitors. “We don’t understand why. It’s as if we have leapfrogged way ahead in terms of therapeutics, and now we have to go back and answer all the questions – the who, what, where, and why of an individual drug and its response in folks.”
In this climate, said Dr. Kaminski, heavy direct-to-consumer advertising of newer myasthenia gravis therapies creates complications. “My patients are highly excited to see, ‘that’s my disease being advertised on Jeopardy.’ ” Many patients are frustrated with the general lack of awareness regarding myasthenia gravis, he added. “But then I’ve had patients who clearly would never qualify for a certain medication getting mailings to their homes.”
Dr. Howard countered that broader awareness of myasthenia gravis can only help. “There’s increasing recognition of the disease, not only by patients, but to some extent, by the treating clinician. Patients are coming to our offices and saying, ‘am I a candidate for this new drug?’ It’s the responsibility of the clinician to decide.”
Individual physicians’ practice patterns vary greatly, said Dr. Kaminski, and very little quantitative data exist here. But based on personal communications, academic-center neurologists tend to use targeted treatments on patients who have failed conventional treatments.
Conversely, Dr. Howard said that, because community physicians rarely see myasthenia gravis, and targeted treatments remain relatively new, many of these providers rely on prednisone, azathioprine, and mycophenolate mofetil.
B-Cell Blockers in Development
Overall, said Dr. Howard, the field of myasthenia gravis treatment development is “very rich. And pharma’s interest in myasthenia has taken off like a rocket. It’s exceptionally gratifying to those of us who take care of these patients whose life is miserable” because of adverse effects and/or nonresponse to current drugs.
“In myasthenia,” added Dr. Kaminski, “we know that T cells are promoting the activity of these auto-reactive B cells.” Many drugs currently in phase 2 or 3 development aim to eliminate B cells or signaling between T and B cells, he said. “That’s where most of the drug development is.”
Leading candidates include telitacicept (Tai’ai, RemeGen), which is both a B-lymphocyte stimulator and a proliferation-inducing ligand. A phase 3 trial (NCT05737160) is ongoing, with primary completion expected in late 2026. A second phase 3 trial (NCT06456580) recently began enrolling. Dr. Howard said that, although early results warranted phase 3 analysis, telitacicept’s phase 2 trial was open label and lacked a placebo group.9 The latter is a critical concern because placebo response rates in myasthenia gravis trials average 35%-40%.
Combined with standard care, the FcRn inhibitor nipocalimab (Johnson & Johnson) enabled patients with AChR, MuSK, and/or LRP4 autoantibodies to improve by 4.70 points on the MG-ADL vs 3.25 points for placebo (P = .002) over 24 weeks in phase 3.10All FcRn inhibitors in development can broadly reduce autoantibody levels, said Dr. Howard. “But what role they will play in myasthenia gravis when they’re several years behind leaders in the field in terms of capturing market remains to be seen.”
Additionally, batoclimab (Immunovant/Harbour BioMed) showed positive topline results in phase 3, and an elevated rate of hypercholesterolemia in treated patients that was transient and consistent with previous research.11 Subsequent to efgartigimod, Dr. Howard said, FcRn inhibitors are full-size antibodies. “I believe that contributes to the adverse events that we see. Efgartigimod is a small FcRn fragment. That’s why it’s a cleaner drug, if you will.”
FcRn inhibitors require periodic retreatment. For example, said Dr. Howard, the ADAPT phase 3 trial of efgartigimod, on which he was lead investigator, employed a cyclic dosing schedule – 4 weeks’ treatment, then observation until patients needed retreatment — because patients demanded it.12 In clinical practice, some patients have gone more than 25 weeks before needing retreatment. One of his patients went beyond 40 weeks. “Others only get around 6-9 weeks. So patient choice again enters the decision-making process.”
Rituximab targets the CD20 protein on B cells nonspecifically, producing general immunosuppression. “That’s problematic in producing significant immunosuppression,” said Dr. Kaminski. Nevertheless, he said, rituximab is very effective for most patients with MuSK-specific MG, and its application to this indication has revealed differences between the MuSK subtype and AChR antibody–positive myasthenia. Specifically, MuSK antibody–positive patients have short-lived plasmablasts, which rituximab eliminates.13
Conversely, said Dr. Kaminski, patients with AChR antibody-positive myasthenia, especially long-term, likely have long-lived plasmablasts producing antibodies. This fact, and these patients’ lack of CD20, likely explain their poor response to rituximab.
A phase 3 trial (NCT04524273) of the CD19 blocker inebilizumab (Uplinza, Amgen) reached primary completion in May. Dr. Howard said that if topline results (unreleased at press time) prove positive, inebilizumab could replace rituximab in MG — provided payers do not reject inebilizumab because of cost.
Packed Early-Development Pipeline
Regarding early-stage projects, said Dr. Howard, the pipeline is packed with compounds that target various aspects of the immune system. “The real question with those is, what’s going to be the side effect profile? All of the trials are very early. We need bigger trials with much longer observation for safety, durability, and degree of efficacy.”
The next potential B cell–targeting game changer, he said, is chimeric antigen receptor (CAR) T cell–based therapy. In a phase 2b trial of Descartes-08 (Cartesian Therapeutics), 71% of treated patients experienced clinically meaningful improvement in MG Composite score at 3 months vs 25% for placebo.14
In early clinical trials, said Dr. Howard, patients treated with Descartes-08 — which uses autologous mRNA to target B-cell maturation antigen — have shown “exceptional improvement” lasting 20 or more months. Because the drug is not ingrained permanently into the genome, Descartes-08 avoids potentially severe side effects of DNA-targeting CAR T candidates. Dr. Howard hopes a phase 3 trial will commence around January 2025.
The tolerance approach exemplified by CNP-106 (COUR Pharmaceuticals) and a myasthenia gravis tolerogen (Toleranzia) seeks to prevent the immune system from recognizing and reacting to the NMJ abnormalities that produce myasthenia gravis, potentially providing a cure. “We look forward to those trials as they come online in the next 1-2 years,” said Dr. Howard.
Unmet Needs
Historically, neurologists believed that all myasthenia gravis symptoms stemmed from muscle fatigue — the more active the muscle, the weaker it gets. However, said Dr. Kaminski, some patients might lack measurable weakness but still complain of fatigue.
Elevated levels of cytokines such as interleukin (IL)–6 or IL-17 also can produce fatigue, he noted. “With the drugs we’re using, certainly the new ones, we’re not specifically targeting this fatigue phenomenon, which has been studied in a very limited fashion.”
In the RAISE-XT zilucoplan trial, participants experienced significant improvement in fatigue scores for up to 60 weeks.15 Although zilucoplan does not address fatigue directly, said Dr. Howard, improving myasthenia gravis overall helps reduce fatigue.
The Myasthenia Gravis Symptoms Patient Reported Outcome (MG Symptoms PRO), which Dr. Kaminski helped develop, includes questions designed to distinguish muscular fatigue from overall physical fatigue.16 “I’m very interested in some of the information that’s coming out on long COVID and its effect on muscle,” Dr. Kaminski added. “We might be able to learn from there that there’s still some pathology going on beyond the neuromuscular junction.”
What the field desperately needs, said Dr. Howard, are biomarkers to identify which patients will and will not respond to certain therapeutics. “We’re not there yet.” Such biomarkers are at least 3-7 years from becoming clinical reality.
Promising antibody-independent serum markers include circulating microRNAs. For example, miRNA-150-5p and miRNA-21-5p are elevated in generalized AChR-positive myasthenia gravis and early-onset myasthenia gravis (occurring before age 50) and decline after immunosuppression and thymectomy.17
Among diagnostic modalities for patients with seronegative myasthenia gravis, said Dr. Kaminski, single-fiber EMG is the most sensitive, at approximately 95%. “It’s not perfect.” Moreover, he said, performing this test accurately requires a highly experienced expert, which many treatment centers lack.
Presently, added Dr. Kaminski, orbital MRI is neither specific nor sensitive enough to be clinically useful. “One needs to be careful with these specialized tests that are published from the best laboratory in the world that does the test, and does it repetitively.” As the search for effective myasthenia gravis biomarkers continues, avoiding false-positive results is as important as avoiding false negatives.
References
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14. Cartesian Therapeutics. Cartesian Therapeutics announces positive topline results from phase 2b trial of Descartes-08 in patients with myasthenia gravis. 2024 Jul 2. https://ir.cartesiantherapeutics.com/news-releases/news-release-details/cartesian-therapeutics-announces-positive-topline-results-phase.
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