An ongoing study will assess the efficacy and safety of an antibody designed to lower immunoglobulin G (IgG) levels in patients with myasthenia gravis (MG), according to a poster presented at the National Organization for Rare Disorders Rare Disease and Orphan Products Breakthrough Summit.

“The ongoing Vivacity-MG phase 3 study will assess the efficacy, safety, and PK/PD of nipocalimab in adult gMG,” the authors wrote.

Enrollment for this phase 2 clinical trial started in July 2021. The multicenter, randomized, double-blind study will compare the effects of nipocalimab vs a placebo. It aims to include around 180 patients previously diagnosed with generalized MG.

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All participants must be experiencing generalized muscle weakness and comply with the criteria to classify as class 2a, 2b, 3a, 3b, 4a, or 5b at baseline, according to the Myasthenia Gravis Foundation of America Clinical Classification. A score of 6 or more points on the Myasthenia Gravis-Activities of Daily Living (MG-ADL) scale is another requisite.

Finally, the study is intended for those patients that exhibited an inappropriate response to previous therapeutic options for MG, such as acetylcholine receptor inhibitors, corticosteroids, and/or immunosuppressants.

“Average change from baseline in MG-ADL score over Weeks 22, 23, and 24 of the double-blind placebo-controlled phase” will be the authors’ primary endpoint.

Moreover, secondary endpoints will evaluate if an improvement in the Quantitative Myasthenia Gravis score at weeks 22 and 24 occurs; the ratio of patients with a change of at least 2 points in the MG-ADL at weeks 1 and/or 2, as well as 22, 23 and 24.

Nipocalimab is a human monoclonal antibody that consists of an effectorless IgG1 that binds to the neonatal Fc portion (FcRn) with great affinity. This technique is intended to decrease the number of pathogenic IgG auto-antibodies that orchestrate the pathophysiology of this disease.

Reference

Ramchandren S, Lee M, Sanga P, Burcklen M, Sun H. Vivacity MG phase 3 study: Clinical trial of nipocalimab administered to adults with generalized myasthenia gravis. Poster presented at: National Organization for Rare Disorders’ (NORD) Rare Disease and Orphan Products Breakthrough Summit; October 17-18, 2022; Washington, DC.