FDA Approves New FcRN Blocker to Treat Generalized Myasthenia Gravis

Johnson & Johnson has received U.S. Food and Drug Administration (FDA) approval for IMAAVY (nipocalimab-aahu), a human FcRn-blocking monoclonal antibody, for the treatment of generalized myasthenia gravis (gMG). The approval, which follows FDA priority review designation, offers a new treatment option in a proven class with the potential for lasting disease control in the broadest population of people living with gMG (adults and pediatric patients 12 years of age and older who are anti-acetylcholine receptor [AChR] or anti-muscle-specific kinase [MuSK] antibody positive).

Approval is supported by data from the pivotal, ongoing Vivacity-MG3 study — the longest primary endpoint of a registrational trial of any FcRn blocker in adults with living with gMG. Highlights of the study include:

• IMAAVY plus standard of care (SOC) provided superior disease control throughout 24 weeks when compared to placebo plus SOC, as measured by improvement in the MG-ADLb score. This translates into patients regaining essential daily functions such as chewing, swallowing, speaking and breathing.

• Participants on IMAAVY plus SOC maintained improvements out to 20 months of follow-up in the ongoing open-label extension (OLE) study in gMG.

• IMAAVY demonstrated a rapid and sustained reduction in autoantibody levels by up to 75 percent from the first dose and throughout a 24-week period of monitoring.

Results from the ongoing Vibrance Phase II/III pediatric study in anti-AChR and anti-MuSK antibody positive adolescents aged 12 to 17 years showed that IMAAVY plus SOC met its primary endpoint with a 69 percent reduction in total serum IgG over 24 weeks, and secondary endpoints of improvements in MG-ADL and QMGc scales.

“The clinical results we’ve seen with IMAAVY represent a significant milestone in the treatment of gMG,” said Nicholas J. Silvestri, MD, professor of neurology at University of Buffalo. “Patients experienced substantial symptom relief and lasting disease control that translated into better daily function and did not fade over 24 weeks in the pivotal Vivacity-MG3 study. Having a treatment that delivers this level of durable symptom stability is a meaningful step forward for managing a complex and unpredictable disease like gMG, and to have it in both AChR+ and MuSK+ adults and pediatric patients 12 years and older brings an additional FcRn treatment to a broader range of patients.”