Nipocalimab Investigation Extends to Younger Patients: Jonathan Strober, MD

The VIBRANCE-MG trial (NCT05265273) is a phase 2/3 investigation of nipocalimab in generalized myasthenia gravis (gMG), a neonatal Fc receptor (FcRn) antagonist (or FcRn blocker), among children aged 2 to younger than 18 years. It is an open-label, uncontrolled multicenter analysis of the medication’s pharmacokinetics, pharmacodynamics, safety, and activity. Nipocalimab works by "basically dropping the amount of immunoglobulins you have in your body,” explained Jonathan Strober, MD, a pediatric neurologist specializing in neuromuscular disorders at the University of California, San Francisco, and Benioff Children's Hospital. This reduction is key, he added, because these excess antibodies "are what cause a lot of the problems in myasthenia by attaching themselves to the receptors on the muscle.”

Strober presented new data from VIBRANCE-MG at the 2025 American Association of Neuromuscular & Electrodiagnostic Medicine meeting, held October 29 to November 1 in San Francisco.

These initial data presented were from the investigation that looked at children 12 years to under 18, with results indicating that the drug had similar results in these pediatric patients as those seen among adult patients. The drug was well tolerated, with safety results being very positive and there being a very low risk of adverse events. Common issues included infections of the nose and pharynx, as well as COVID-19. Although acknowledging that having lower antibody levels increases the risk of infection, Strober stated that this risk “doesn't really seem to be that significant of a risk, which is great.”

The results also demonstrated positive long-term engagement, as “most of the patients continued on through 72 weeks of taking this medication, so past the initial phase of the safety study,” Strober explained. Only one patient discontinued treatment.

The investigation is ongoing internationally. However, recruitment is challenging, as it is “just really hard for us to get patients into trials like these” due to difficulties in finding younger patients with the positive antibodies needed for enrollment or patients whose symptoms fall within the acceptable clinical trial severity range. Furthermore, it is “harder to do some of the functional testing that we do for these patients” in the younger cohorts, Strober noted.