Nipocalimab up for approval for gMG in the US
Therapy, if approved, could treat most gMG patients
Johnson & Johnson has submitted an application to the U.S. Food and Drug Administration (FDA) seeking approval of nipocalimab to treat people with generalized myasthenia gravis (gMG).
The application covers gMG patients who are positive for disease-causing antibodies against acetylcholine receptors (AChRs), muscle-specific kinase (MuSK), and low density lipoprotein receptor-related protein 4 (LRP4), which together account for around 95% of all gMG cases.
If approved, nipocalimab would cover the broadest population of antibody-positive gMG patients of any gMG therapy on the market.
“The filing for approval of nipocalimab represents an important step forward as Johnson & Johnson continues to push the boundaries of research to develop innovative solutions to treat autoantibody-driven diseases,” Bill Martin, PhD, global therapeutic area head of neuroscience at Johnson & Johnson Innovative Medicine, said in a company press release.
Targeting antibody attacks
MG arises when self-reactive antibodies attack proteins necessary for proper nerve-muscle communication, including AChR, MuSK, and LRP4. These antibodies belong to a class of antibodies called immunoglobulin G (IgG).
Nipocalimab is an antibody that’s designed to block the activity of the neonatal Fc receptor (FcRn), a protein that normally helps prevent IgGs circulating in the bloodstream from being degraded. By blocking it, the treatment is expected to accelerate the degradation of disease-driving antibodies, lowering their levels in the bloodstream and easing gMG symptoms. This is the same class of therapies to which the approved treatments Rystiggo (rozanolixizumab-noli) and Vyvgart (efgartigimod alfa-fcab) belong.
The regulatory filing was supported by data from the Phase 3 Vivacity-MG3 trial (NCT04951622), which is evaluating nipocalimab’s safety and efficacy in 199 adults with gMG who had insufficient response to standard-of-care treatments. Most participants (153 people) had antibodies against AChRs, MuSK, and/or LRP4.
Patients were randomly assigned to receive intravenous (into-the-vein) infusions of nipocalimab (15 mg/kg after an initial 30 mg/kg loading dose) or a placebo once every two weeks, in addition to standard care, for about six months.
The study’s main goal was to evaluate changes in disease severity over the course of treatment in autoantibody-positive patients. This was evaluated by assessing changes in the score of the MG Activities of Daily Living (MG-ADL), a patient-rated measure of disease severity.
Nipocalimab-treated patients saw their MG-ADL scores drop by a mean of 4.7 points between the study’s start and the last three weeks of treatment — a significant improvement relative to the 3.25-point reduction observed in the placebo group.
Other secondary outcomes were also met, including significant improvements in the scores of the Quantitative MG, a clinician-rated measure of MG disease severity.
Johnson & Johnson says nipocalimab is the first and only FcRn blocker to demonstrate sustained disease control when combined with standard care over a period of six months of consistent dosing in a clinical trial. Nipocalimab has also been found to be safe and well tolerated in clinical trials.
“We are encouraged by the potential of nipocalimab to provide sustained disease control for people living with generalized myasthenia gravis, a chronic, life-long disease,” Martin said.
Participants in Vivacity-MG3 trial have the option of continuing treatment for up to two more years in an open-label extension phase that’s expected to finish in 2026.
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