Johnson & Johnson (J&J) has unveiled positive results for its investigational drug nipocalimab from the Phase 3 Vivacity-MG3 study in patients with generalised myasthenia gravis (gMG).

Nipocalimab is designed to block FcRn and reduce levels of circulating immunoglobulin G (IgG) antibodies while preserving immune function without causing broad immunosuppression.

By blocking IgG from binding to FcRn in the placenta, the drug is believed to prevent the transplacental transfer of maternal alloantibodies to the foetus.

Vivacity-MG3 is a Phase 3 clinical trial specifically designed to evaluate sustained efficacy and safety with consistent dosing in this unpredictable chronic condition.

The double-blind placebo-controlled trial enrolled 199 adults, with antibody-positive or -negative adult gMG patients with insufficient response to ongoing standard of care (SOC) therapy.

They were randomised to receive either nipocalimab plus current SOC or placebo plus SOC, with the mean change in MG-ADLa score in antibody-positive patients as the primary endpoint.

Also, the change in QMGc score is a key secondary endpoint, and long-term safety and efficacy were further assessed in an ongoing OLE phase.

Neurological Institute Foundation C. Besta neuroimmunology and muscle pathology unit Carlo Antozzi said: “The sustained response of nipocalimab over six months among this broad myasthenia gravis population is an important finding given the chronic, unpredictable exacerbations typically seen with myasthenia gravis.

“We are encouraged by the potential of nipocalimab to uniquely help address this gap for people living with myasthenia gravis.”

In the study, patients treated with nipocalimab plus SOC achieved superiority over placebo plus SOC, the primary endpoint of improvement in the MG-ADL score from baseline over 24 weeks.

In addition to the primary endpoint, the study also met critical secondary endpoints including improvement in the strength and function of different muscle groups.

Nipocalimab plus SOC resulted in significantly greater QMGd compared with placebo plus SOC, along with MG-ADL response, over weeks 22, 23 and 24.

Also, it showed consistent safety and tolerability with other nipocalimab studies, said J&J.

Johnson & Johnson Innovative Medicine Autoantibody and Maternal Fetal Immunology Disease Area Leader Vice President Katie Abouzahr said: “We are thrilled to present yet another dataset for nipocalimab at the EAN 2024 Annual Meeting highlighting our commitment to providing innovative treatments for autoantibody-driven diseases.”