Adding nipocalimab to standard-of-care (SoC) demonstrates sustained disease control through week 120 in adult patients with antibody-positive generalized myasthenia gravis (gMG), including anti-AChR* or anti-MuSK**, according to the Vivacity-MG3 open-label extension (OLE) study presented at AAN 2026.
“For people living with gMG, consistent and durable symptom control is the central goal of treatment,” said study co-author Associate Professor Constantine Farmakidis, University of Kansas Medical Center.
“These long-term results, now extending beyond 2 years, provide further evidence that disease control, as initially observed in the nipocalimab phase III pivotal study, can be sustained, and add to the body of evidence that may guide clinical decision-making,” Farmakidis added.
Nipocalimab, added to SoC, is the first approved neonatal Fc receptor blocker for the treatment of gMG in adult and adolescent (aged ≥12 years) patients who are anti-AChR or anti-MuSK antibody-positive, said co-author Dr Carlo Antozzi from Fondazione IRCCS Istituto Neurologico Carlo Besta in Milan, Italy, who presented the study.
In the double-blind phase of the study, individuals with AChR, MuSK, or LRP4*** antibody-positive gMG were randomly assigned in a 1:1 ratio to receive either nipocalimab+ (n=77) or placebo (n=76) in addition to SoC for 24 weeks.
Following completion of the 24-week double-blind phase, 137 antibody-positive participants entered the 120-week OLE phase, in which those initially receiving nipocalimab continued their treatment regimen (nipocalimab/nipocalimab + SoC group), and those previously on placebo were switched to nipocalimab (placebo/nipocalimab + SoC group).
By week 96, improvements in MG-Activities of Daily Living (MG-ADL) scores were observed in both treatment groups, with mean reductions of 6.47 points in the nipocalimab/nipocalimab group and 6.69 points in the placebo/nipocalimab group. [AAN 2026, abstract 9-19]
As a result, 50 percent of participants demonstrated minimal symptom expression (MSE), with nearly one-third achieving sustained MSE for ≥8 weeks.
Quantitative Myasthenia Gravis (QMG) scores also improved in both the nipocalimab/nipocalimab and placebo/nipocalimab groups, with mean reductions of 6.47 and 6.69 points, respectively.
Immunoglobulin G (IgG) levels decreased from baseline to week 96, with 64.06- and 63.24-percent reductions in the nipocalimab/nipocalimab and placebo/nipocalimab groups, respectively.
At baseline, approximately 45 percent of patients were using corticosteroids. In the nipocalimab/nipocalimab group, corticosteroid discontinuation began as early as week 24 and continued to decline over time, resulting in more than half of patients (57.3 percent) reaching a prednisone equivalent dose of ≤10 mg per day.
In terms of safety, the rates of adverse events were comparable between the double-blind and OLE phases, with no new safety concerns observed, Antozzi noted.
“Overall, long-term treatment with nipocalimab demonstrated clinically meaningful and sustained disease control over 120 weeks in a broad population of autoantibody-positive patients with gMG, while maintaining an acceptable safety profile,” he concluded.