Efficacy of Nipcalimab To Treat Myasthenia Gravis: Updates From Vivacity-MG3 Trial

Sindhu Ramchandren, MD, Executive Medical Director, Neuroscience and Disease Cluster Lead for Neuroimmunology and Neuromuscular Disorders at Johnson & Johnson, discusses updated results from the Vivacity-MG3 clinical trial in patients with generalized myasthenia gravis (MG).

MG is a chronic autoimmune neuromuscular disease characterized by weakness of the skeletal muscles. Common symptoms include weakness of the muscles that control the eye and eyelid, facial expressions, chewing, talking, and swallowing. Weakness tends to increase during periods of activity and improve after periods of rest. The condition results from a defect in the transmission of nerve impulses to muscles, which is due to the presence of antibodies against acetylcholine receptors. The etiology of MG is not known.

The Vivacity-MG3 clinical trial (NCT04951622) was a phase 3, multicenter, randomized, double-blind, placebo-controlled study evaluating the efficacy and safety of nipocalimab in patients with antibody-positive generalized MG. There is also an ongoing open-label extension evaluating the long-term safety and efficacy of nipocalimab in patients with MG. Nipocalimab is an investigational monoclonal antibody designed to block FcRn and reduce levels of circulation immunoglobulin G (IgG) antibodies.

Results of the study showed that patients treated with nipocalimab plus standard of care maintained improvements in their MG-ADL and QMG scores over 84 weeks with sustained reductions in total IgG. The mean change in MG-ADL score was -5.64 from baseline after 60 weeks in the open-label extension participants receiving nipocalimab plus standard of care. The mean change in MG-ADL score for participants who transitioned from placebo and standard of care to nipocalimab plus standard of care was -6.01. 45% of patients in the antibody-positive population receiving steroids at baseline were able to decrease or discontinue use. The safety profile of nipocalimab was consistent and tolerable throughout the open-label extension.

Additionally, patients treated with nipocalimab plus standard of care achieved statistically significant improvements in QMG scores by -4.9 compared to placebo plus standard of care. Patients in the nipocalimab plus standard of care group were also four times more likely to sustain symptom improvement at 20 weeks compared to the placebo plus standard of care group. 36.4% of patients treated with nipocalimab versus 10.5% of patients on placebo spent greater than 75% of the study duration demonstrating improvements in QMG score.

Chapters:
Introduction 00:00
Myasthenia Gravis Overview 0:33
Nipocalimab Overview 2:21
Vivacity-MG3 Study 3:19
Take Home Message 7:45