TL;DR
Get workout gear delivered free with Prime
- Fast, free delivery on millions of items
- Prime Video, Amazon Music and more included
- Member-only deals all year
Open-label ADAPT SERON data presented at the AANEM annual meeting suggest that some patients with generalized myasthenia gravis who lack detectable AChR antibodies may respond more slowly to intravenous efgartigimod. Neurologist James F. Howard Jr. said clinicians may need to allow three or four treatment cycles before deciding the drug is not helping, while also monitoring for patients who do not respond.
Some patients with generalized myasthenia gravis who lack detectable acetylcholine receptor (AChR) antibodies may need more treatment cycles before responding meaningfully to intravenous efgartigimod, according to open-label data from the ADAPT SERON trial presented at the American Association of Neuromuscular & Electrodiagnostic Medicine annual meeting. Trial investigator James F. Howard Jr. said clinicians may need to wait through three or four cycles before judging whether treatment is ineffective, rather than stopping after two.
The findings concern patients with generalized myasthenia gravis who test negative for AChR antibodies, including people without identifiable antibodies to MuSK or LRP4. Howard, a neurologist at the University of North Carolina at Chapel Hill, discussed the data in an interview with MedPage Today. The report describes the results as open-label data; it does not provide numerical response rates, a comparison group, or detailed measures of improvement.
Howard said most participants in the original ADAPT trial who responded did so quickly, with meaningful improvement often appearing during the first treatment cycle. In contrast, he said, AChR-negative patients may have a slower onset of effect, with improvement emerging after two or three cycles. He suggested clinicians consider allowing three or even four cycles—roughly six months, in his description—before concluding that treatment is not working.
Howard also cautioned against continuing treatment without evidence of benefit. He said clinicians need to identify people who do not respond to avoid wasting time and exposing them to potential adverse effects without benefit. He reported no new safety signals in the patient subgroups discussed, but the source material does not give event counts or a detailed safety analysis.
A Longer Trial Before Stopping Treatment
The findings could affect how clinicians assess efgartigimod in a patient group with fewer targeted treatment options. Howard said people without detectable AChR antibodies, particularly those also negative for MuSK and LRP4 antibodies, represent about 10% of the myasthenia gravis population and have had limited access to newer targeted therapies. If some of these patients improve later than others, stopping after only two cycles could mean ending treatment before a possible response becomes apparent.
That possibility is not a recommendation to continue indefinitely. The decision involves weighing the chance of delayed improvement against the time, treatment burden and potential adverse effects. The available report does not establish which individual patients will respond, how much benefit they may gain, or whether waiting longer produces better outcomes than changing therapy. For patients and clinicians, the practical message is to assess response over time while continuing to monitor symptoms and safety.
Products Worth Considering
Withings Sleep Under-Mattress Sleep Tracking Pad
BowFlex Results Series SelectTech Dumbbells
LEVOIT Vital 100S-P Smart Air Purifier with Washable Pre-Filter
As an affiliate, we earn on qualifying purchases.
What ADAPT SERON Adds
Efgartigimod, marketed as Vyvgart, is an intravenous treatment studied for generalized myasthenia gravis. The ADAPT SERON trial focuses on patients without detectable AChR antibodies, a subgroup that includes people who may also lack identifiable MuSK and LRP4 antibodies. The new report presents open-label findings from that study at the annual meeting of the American Association of Neuromuscular & Electrodiagnostic Medicine.
Howard said the original ADAPT trial showed that most responding participants improved during the first cycle, while the newer observations point to a potentially slower response among AChR-negative patients. He also discussed possible differences in disease biology: AChR antibodies are associated with complement activation that can damage the neuromuscular junction, while the role of complement in patients with no detectable antibodies remains uncertain. He cited basic science evidence suggesting complement may be present in those junctions, but that does not establish the mechanism in these patients.
“We don’t have the answer and the understanding at this point, it’s being looked at.”
— James F. Howard Jr., MD
Response Timing and Biology Remain Open
The report does not specify how many patients were included in the relevant subgroups, what proportion improved after each cycle, how improvement was measured, or how long participants were followed. Because the data are open-label, the supplied information also does not establish how the response pattern compares with a control group. Howard’s estimate that some patients may need three or four cycles is a clinical interpretation of the observations, not a confirmed threshold that applies to every patient.
It is also unclear which features predict a delayed response or how clinicians should distinguish a patient who may improve later from one who will not benefit. The biological explanation remains under investigation, especially for patients with no detectable AChR, MuSK or LRP4 antibodies. The comments about similar safety across subgroups are not accompanied in the source report by detailed rates, severity, or duration of adverse events.
Further Trial Data Will Guide Decisions
Additional ADAPT SERON results will be needed to clarify the number of patients who respond after later cycles, the size and duration of improvement, and the safety profile in each antibody subgroup. The source report does not identify a date for a full publication or describe a specific next analysis. Howard said the slower response pattern is being studied, and the meeting presentation may prompt further examination of treatment timing in this population.
For now, the findings support individualized review rather than a fixed stopping rule based on two cycles alone. Clinicians will need to weigh observed changes in each patient against treatment risks and burden, while patients should discuss response expectations and treatment decisions with their care team.
Key Questions
Which patients may take longer to respond to efgartigimod?
The report concerns people with generalized myasthenia gravis who lack detectable AChR antibodies. Howard said this may include patients without identifiable MuSK or LRP4 antibodies, but the report does not define a reliable way to predict an individual response.
How long might clinicians wait before deciding treatment is not working?
Howard said some patients may need three or four cycles, or about six months, before a meaningful improvement is apparent. This is his interpretation of open-label findings, not a universal treatment rule established by the report.
Does the study show that efgartigimod is effective for every seronegative patient?
No. The report says the data suggest continued efficacy and safety in the studied group, but it provides no response rates or evidence that every patient benefits. Howard stressed the need to recognize patients who do not respond.
Were new safety problems reported?
Howard said investigators had seen no new safety signals in the subgroups discussed. The report does not provide detailed adverse-event counts, so it does not establish the precise risks for each subgroup.
What remains unknown about why the response may be slower?
The reason has not been established. Howard discussed possible disease-mechanism differences and basic science findings involving complement, but said the biology of patients without detectable antibodies is still under investigation.
Source: rss
