Johnson & Johnson has presented phase 3 data on nipocalimab in generalized myasthenia gravis (gMG), providing a look at how its $6.5 billion prospect matches up to the approved FcRn rivals from argenx and UCB.
Having paid $6.5 billion for nipocalimab and the rest of Momenta Pharmaceuticals in 2020, J&J racked up its first phase 3 win earlier this year. The top-line readout revealed the study hit its primary endpoint but left key questions about J&J’s competitive positioning unanswered. J&J provided a closer look at the data at the European Academy of Neurology 2024 Congress Friday.
The study enrolled 153 antibody-positive gMG patients. People taking nipocalimab plus standard of care had a 4.7-point improvement on the MG-ADL symptom scale after 22 to 24 weeks of treatment. J&J saw a 3.25-point improvement in the control group. The drugmaker also linked nipocalimab to improvements on the QMG disease severity scale, scoring (PDF) a 4.86 reduction versus the 2.05 dip in the control arm.
UCB won (PDF) FDA approval on the strength of a study that linked Rystiggo to a 2.6-point improvement in MG-ADL compared to placebo at Day 43. Sixty-eight percent of Vyvgart patients in argenx’s pivotal trial had (PDF) at least a two-point improvement in MG-ADL versus 30% of their counterparts on placebo.
J&J targeted a broader patient population than its rivals did. Argenx won FDA approval for Vyvgart in 2021 in people who are positive for anti-AChR antibodies. UCB brought Rystiggo to market in 2023 with a label that covers patients with anti-AChR or anti-MuSK antibodies. J&J’s trial enrolled people with antibodies against AChR, MuSK and LRP4.
However, most gMG patients are eligible for treatment with the existing drugs. Up to 90% of people with gMG have antibodies against AChR. The subpopulation of LRP4 patients included in the J&J trial accounts for up to 5% of cases.
J&J studied an intravenous dose of nipocalimab in the phase 3 trial. Vyvgart is given the same way. Argenx also has a subcutaneous product, Vyvgart Hytrulo, on the market. Rystiggo is a subcutaneous infusion. Argenx said its subcutaneous product drove growth in the first quarter, when global sales across both formulations rose to $398 million. J&J plans to file for approval in gMG later this year and is pursuing other indications.