J&J, with adult approval in sight, posts adolescent myasthenia gravis data on $6.5B FcRn blocker

Johnson & Johnson has burnished the evidence for nipocalimab, adding a sliver of data in adolescents with generalized myasthenia gravis (gMG) to the growing case for its near-approval FcRn blocker.

Nipocalimab, the molecule J&J acquired in its $6.5 billion takeover of Momenta Pharmaceuticals, is now under review at the FDA as a treatment for adults with gMG. While the adult population is the meat of the market, around 10% of new cases of the chronic neuromuscular disease are in adolescents aged 12 to 17 years. Hospitalizations, including stays in intensive care, are common in pediatric patients.

Tuesday, Oct. 15, J&J shared phase 2/3 data that suggest nipocalimab can help those patients. Presenting at the American Association of Neuromuscular & Electrodiagnostic Medicine Annual Meeting, J&J reported reductions in immunoglobulin G (IgG) in adolescents who received nipocalimab infusions for 24 weeks.

Patients experienced a 69% reduction in total serum IgG after receiving nipocalimab every two weeks on top of standard of care. The reduction caused the trial to hit its primary endpoint. J&J also reported hits on two secondary endpoints that assessed disease activity. Scores on the MG-ADL scale fell 2.4 points from a baseline of 4.29, edging closer to the zero that indicates the absence of symptoms.

The data come from a small trial. J&J plans to enroll 12 people aged 2 to 18 years in the ongoing trial and said four of five patients had minimum symptom expression on the MG-ADL scale after the treatment phase. While the study is small, the fact its results are in line with data from larger trials in adults gives credence to the findings.

J&J’s rivals for the gMG space are running equally small pediatric clinical trials. Argenx, the front-runner in the FcRn market, is enrolling 12 children in a phase 2/3 study of Vyvgart. UCB has the same enrollment target for a pediatric phase 2/3 study of its FcRn drug Rystiggo.

Nipocalimab could start competing with Vyvgart and Rystiggo for the adult gMG market next year. J&J filed for FDA approval of the FcRn blocker in the indication in August. The filing might be the first in a wave of submissions for the candidate, which J&J has identified as a molecule that could have an impact on a range of conditions.