Johnson & Johnson Receives FDA Approval for IMAAVY™ to Treat Generalised Myasthenia Gravis
Thursday, May 01, 2025
Johnson & Johnson has announced that the U.S. Food and Drug Administration (FDA) has approved IMAAVY™ (nipocalimab-aahu), a monoclonal antibody that blocks the neonatal Fc receptor (FcRn), for the treatment of generalised myasthenia gravis (gMG).
Generalised myasthenia gravis is a long-term autoimmune disease marked by muscle weakness and fatigue. Most individuals affected have antibodies that interfere with the communication between nerves and muscles, and the condition often progresses beyond the eye muscles to affect speech, swallowing, and breathing.
IMAAVY is designed to selectively reduce levels of immunoglobulin G (IgG), including the harmful autoantibodies that drive gMG, while leaving other immune functions largely unaffected. The treatment has shown long-lasting disease control in a broad patient population, including those with limited options such as paediatric patients.
The approval follows a Priority Review and expands treatment options for both adults and adolescents aged 12 years and older who test positive for either anti-acetylcholine receptor (AChR) or anti-muscle-specific kinase (MuSK) antibodies.
Approval was based on results from the ongoing Phase 3 Vivacity-MG3 study, which is the longest registrational trial for an FcRn blocker in adults with gMG.
These benefits were seen in patients’ ability to perform essential daily functions such as speaking and breathing. Improvements were sustained through 24 weeks, and further benefits were observed in the open-label extension study, continuing out to 20 months.
The treatment also led to a rapid and consistent reduction in IgG autoantibodies by up to 75% from the first dose, maintained over the 24-week period. The safety profile of IMAAVY was consistent and comparable between adult and adolescent populations across the Vivacity-MG3 and Vibrance-MG studies.
In the Vibrance study, which focused on paediatric patients aged 12–17 years, IMAAVY met its primary endpoint by reducing total serum IgG by 69% over 24 weeks. Improvements were also seen on standard measures of disease activity.
IMAAVY is currently approved in the United States for the treatment of gMG in patients aged 12 and older who are AChR or MuSK antibody positive. Submissions for approval in other countries are under review by global health authorities.
Source: jnj.com
