Johnson & Johnson has dropped plans to develop its recently approved autoimmune drug Imaavy (nipocalimab) as part of a combination therapy for rheumatoid arthritis (RA), after the treatment showed no benefit in a mid-stage trial.

The FcRn-blocking monoclonal antibody won US approval in May to treat generalised myasthenia gravis (gMG). But in the phase 2a Daisy proof-of-concept study, adding Imaavy to an anti-TNFα therapy failed to improve outcomes for patients with refractory RA after 12 weeks.

“Based on these findings, Johnson & Johnson has decided not to proceed with the clinical development of nipocalimab in combination with an anti-TNFα therapy for RA,” the company said.

No study data were released, but the result marks an early setback for a medicine J&J has previously described as a potential blockbuster with more than $5 billion in annual peak sales. The company is still pursuing development of Imaavy across a wide range of autoantibody-driven diseases.

The drug’s US approval for gMG followed a priority review and was supported by data from the Vivacity-MG3 study, which showed improvements in daily functioning such as speaking and swallowing compared with placebo. Patients on treatment also maintained benefits in a long-term extension trial.

David Lee, global immunology therapeutic area head at J&J, said at the time of approval: “This approval is the result of years of scientific commitment, collaboration and determination for our nipocalimab program, and we’re proud to bring this new treatment option to patients living with anti-AChR or anti-MuSK antibody positive gMG.”

The drug has also shown promise in adolescents with gMG, achieving its primary and secondary endpoints in the Vibrance study. It has generally demonstrated a consistent safety profile across both adult and paediatric trials.

While the RA disappointment narrows its potential in combination settings, J&J maintains that the medicine could help reshape treatment in other areas where antibody-driven diseases remain difficult to manage. Submissions seeking approval in gMG are under review with regulators worldwide.