Johnson & Johnson's New Drug Comes Under Fire: 4.7-Point Improvement Fails to Ease the Plight of gMG Patients, Can the Efficacy Stand Up to Market Tests?

On August 29, 2024, Johnson & Johnson formally filed a Biologics License Application (BLA) with the U.S. Food and Drug Administration (FDA) seeking the world's first approval of the FcRn monoclonal antibody Nipocalimab for the treatment of patients with generalized myasthenia gravis (gMG).

In June, the Phase III VIVACITY-MG3 study of Nipocalimab for gMG published positive results, showing that the combination of Nipocalimab with standard of care (SOC) significantly improved MG-ADL scores over 24 weeks compared with placebo-combined SOC, meeting the study's primary endpoint.

The study was a double-blind, placebo-controlled trial that enrolled a large number of patients with AChR+, MuSK+, and/or LRP4+, who accounted for approximately 95% of the total number of patients with gMG. At weeks 22, 23, and 24, patients receiving Nipocalimab+SOC improved MG-ADL scores by 4.70 points from baseline, which was significantly higher than 3.25 points in the placebo +SOC group (P=0.002). For people with gMG, a 1 to 2 point change in the MG-ADL score can mean the difference from a normal diet to frequent food choking, or from shortness of breath at rest to needing to use a ventilator.

In addition, the study achieved several key secondary endpoints: at week 22 and 24, the Nipocalimab+SOC group showed significant improvements in strength and function across different muscle groups assessed by QMG compared to the placebo +SOC group (P<0.001); At weeks 22, 23, and 24, the MG-ADL response was significantly higher in the Nipocalimab+SOC group (≥2 points improvement from baseline) than in the placebo +SOC group (P=0.021), further highlighting the potential of Nipocalimab to mitigate the impact of gMG on patients' daily lives.

Nipocalimab is a high-affinity, fully human, glycated, non-effective monoclonal antibody that selectively blocks FcRn, thereby reducing circulating immunoglobulin G (IgG) antibodies, including autoantibodies and alloantibodies that cause a variety of diseases.

Nipocalimab was originally developed by AnaptysBi and subsequently transferred to Momenta. In August 2020, Johnson & Johnson acquired Momenta for $6.5 billion, giving it the rights to the drug.

gMG is a chronic, lifelong, rare, and highly disabling autoantibody-mediated neuromuscular disease characterized by fluctuating myasthenia. Two FcRn monoclonal antibodies have previously been approved by the FDA, Argenx/ Re-ting's efgartigimod and UXbi's rozanolixizumab, both approved for gMG indications. Egamod has shown good market prospects, 2022 is its first full year of sales in overseas markets, sales exceeded 400 million US dollars, and 2023 reached 1.19 billion US dollars, among the "blockbuster" drugs.