Healthcare products company Johnson & Johnson (J&J) (NYSE:JNJ) said on Wednesday that it has received US Food and Drug Administration (FDA) approval for IMAAVY (nipocalimab-aahu), a novel FcRn-blocking monoclonal antibody, for the treatment of generalised myasthenia gravis (gMG).

IMAAVY is the first and only FcRn blocker approved for use in both adult and paediatric patients aged 12 and older who are anti-acetylcholine receptor (AChR) or anti-muscle-specific kinase (MuSK) antibody positive.

The approval is based on results from the Vivacity-MG3 study, in which IMAAVY demonstrated rapid and sustained immunoglobulin G (IgG) reduction and 20 months of symptom relief. In combination with standard of care, IMAAVY provided significant improvement in daily functions such as chewing, swallowing, and breathing.

Data from the ongoing Vibrance Phase 2/3 paediatric study shows a 69% reduction in IgG levels and measurable improvement in clinical scores over 24 weeks.

IMAAVY is designed to selectively target harmful IgG autoantibodies while sparing other immune functions, addressing a critical need in a debilitating disease with limited long-term treatment options.

Anti-AChR and anti-MuSK antibody positive patients represent over 90% of the antibody-positive gMG population.

J&J added that IMAAVY has demonstrated a consistent safety and tolerability profile across both adult and paediatric trials.