SPRING HOUSE, PA — Johnson & Johnson (NYSE: JNJ) reported that adolescents with generalized myasthenia gravis maintained improvements in daily function and muscle strength through two years of IMAAVY treatment, extending the evidence supporting the drug’s use in patients as young as 12.
The findings come from the long-term extension of the Phase 2/3 Vibrance-MG study and are among 15 IMAAVY abstracts being presented at the 2026 Myasthenia Gravis Foundation of America Scientific Session and American Association of Neuromuscular & Electrodiagnostic Medicine Annual Meeting.
Among adolescents with anti-AChR antibody-positive generalized myasthenia gravis who had available data at Week 108, the mean change from baseline was a 2.88-point improvement on the Myasthenia Gravis Activities of Daily Living scale and an 8.25-point improvement on the Quantitative Myasthenia Gravis assessment.
J&J reported that those improvements were consistent with results observed at Weeks 4 and 24 and at intervening assessments through two years.
The extension also showed reduced corticosteroid use among some participants. Of six adolescents taking corticosteroids when they entered the study, three reduced their doses and one discontinued corticosteroids after two years of IMAAVY treatment.
No new safety signals were identified during up to two years of treatment, according to the company. The safety profile in adolescents was similar to that previously reported in adults.
The adolescent findings add longer-term evidence for IMAAVY, or nipocalimab-aahu, which is approved by the U.S. Food and Drug Administration and European Medicines Agency for patients ages 12 and older with anti-AChR or anti-MuSK antibody-positive generalized myasthenia gravis.
Generalized myasthenia gravis is an autoimmune disorder characterized by muscle weakness that can fluctuate and affect functions including vision and movement.
J&J is also presenting retrospective survey findings examining why adults with anti-AChR or anti-MuSK antibody-positive disease switched from other advanced treatments to IMAAVY.
Healthcare professionals identified fluctuating symptom control as the most common reason for discontinuing a previous advanced therapy, cited for 54.6% of patients in the survey.
Among 97 patients who transitioned to IMAAVY, a preference for a consistent treatment schedule was cited for 62.9%, while 56.7% switched in hopes of improved efficacy.
Healthcare professionals subsequently rated 73.2% of those patients as “much improved” or “very much improved.” Among patients receiving prednisone, 76.4% reduced their dose and 5.5% discontinued it.
The survey findings are retrospective and reflect healthcare professionals’ assessments rather than results from a randomized clinical trial, making them distinct from the prospective Vibrance-MG data.
“Fluctuating symptom control emerged as the leading reason healthcare professionals reported for discontinuing prior therapy,” said David Lee, J&J’s global immunology therapeutic area head.
IMAAVY is an FcRn blocker designed to reduce pathogenic immunoglobulin G antibodies while preserving B-cell function. The drug’s longer-term performance in adolescents and J&J’s real-world treatment-switching data broaden the evidence the company is assembling around sustained disease control across age groups.
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