Efficacy and Safety of Nipocalimab in Adults With Generalised Myasthenia Gravis: An Asian Subgroup Analysis of the Vivacity-MG3 Study.

BACKGROUND AND PURPOSE: The phase 3, randomised, double-blind, placebo-controlled Vivacity-MG3 trial demonstrated that nipocalimab, a neonatal Fc receptor blocker, provided sustained disease control over 6 months when added to standard of care therapies in patients with antibody-positive generalised myasthenia gravis (gMG). Here we present the Vivacity-MG3 Asian subgroup analysis.

METHODS

Recruited patients were randomised (1:1) to receive either nipocalimab (30 mg/kg loading dose, then 15 mg/kg every 2 weeks for maintenance) or placebo infusions every 2 weeks, both alongside standard of care therapy, for 24 weeks. The primary endpoint was the difference between nipocalimab and placebo groups in least-squares mean change from baseline in Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score over weeks 22-24 in seropositive patients. Other endpoints included changes in Quantitative Myasthenia Gravis (QMG) score and MG-ADL response rates. Adverse events were evaluated in all treated patients.

RESULTS

This analysis included 56 patients from East Asia (nipocalimab n=28; placebo n=28). The least-squares mean difference in change in MG-ADL score from baseline to weeks 22-24 was -1.35 (95% confidence interval [CI] -2.93 to 0.24) in favour of nipocalimab in the Asian population, consistent with the overall population (-1.45 [95% CI -2.38 to -0.52]). Numerical improvements in QMG score and MG-ADL response rates were observed with nipocalimab in the Asian population, generally aligning with the overall study findings. Treatment-emergent adverse event incidence was comparable between treatment arms.

CONCLUSIONS

Nipocalimab demonstrated a favourable efficacy and safety in the East Asian subgroup, with outcomes generally consistent with the overall Vivacity-MG3 study, supporting its role as a treatment option for gMG in this population.