J&J's $6.5B autoimmune drug hits phase 3 goal, teeing up approval talks and keeping heat on argenx, UCB

Johnson & Johnson’s $6.5 billion autoimmune drug has hit the mark in a phase 3 trial. The success tees J&J up to talk to regulators about approving the anti-FcRn antibody in generalized myasthenia gravis (gMG), although questions about the competitiveness of the late-to-market asset remain unanswered. 

J&J acquired the antibody, nipocalimab, in its $6.5 billion takeover of Momenta Pharmaceuticals. The deal secured J&J a challenger to now-approved drugs from argenx and UCB, and a chance to pursue the wide range of indications that could potentially respond to FcRn blockade. Argenx’s failures have dialed down the hype, which pegged FcRn as the next TNF, but billions of dollars could still be up for grabs.

Monday, J&J shared details of its attempt to claim a piece of the pie, reporting that a phase 3 clinical trial of nipocalimab in gMG met its primary endpoint. The study compared the effect of nipocalimab and placebo on MG-ADL, an assessment of symptoms that affect the daily lives of patients. 

J&J is yet to share data from the trial—and the details will be key. Argenx won FDA approval for its FcRn drug, Vyvgart, in gMG late in 2021, added a subcutaneous formulation in 2023 and reported $1.2 billion in preliminary global net product sales last year. UCB entered the U.S. market with Rystiggo in June.

J&J has previously sounded bullish about its prospects of coming up from behind. Talking to investors late last year, David Lee, M.D., Ph.D., global therapeutic area head, immunology for J&J’s Janssen unit, said his team was anticipating an up to 77% reduction in immunoglobulin G (IgG). Rystiggo reduced IgG by 71% to 78%, depending on the dose. The figures for the two Vyvgart formulations range (PDF) from 62% to 66%. 

If J&J can drive deeper reductions in IgG, the class of antibodies that includes the drivers of gMG, it may have an edge over the competition in terms of efficacy. The company is also aiming to differentiate its drug in terms of safety, citing specificity for IgG to make its case, and convenience. Lee said patients will take its drug “at home twice monthly with regular stable dosing in a differentiated subcutaneous device.” 

J&J plans to talk to regulators about bringing nipocalimab to market in gMG while continuing to go after other indications. The company shared details of its progress in Sjögren's disease alongside news of the gMG data. In a phase 2 trial, J&J linked nipocalimab to significant improvements on a composite scale that assesses organ disease activity.

According to J&J, the results represent the first positive results of an investigational anti-FcRn treatment in Sjögren's. The pursuit of the disease plays to a potential strength of nipocalimab. Sjögren's is more common in women than men, suggesting J&J’s work to develop and validate a molecule that is safe to use in pregnant individuals could be a differentiator.