FDA

Imaavy OK’d for generalized myasthenia gravis

May 5, 2025

Brand name: Imaavy

Generic name: nipocalimab-aahu

Manufacturer: Johnson & Johnson

Approval date: April 30, 2025

FDA approved Imaavy (nipocalimab-aahu), a neonatal Fc receptor blocker, for the treatment of generalized myasthenia gravis (gMG) in adult and pediatric patients ≥12 years of age who are anti-acetylcholine receptor (AChR) or anti-muscle-specific tyrosine kinase (MuSK) antibody positive.

Efficacy

Approval was based on data from the phase 3 Vivacity-MG3 study (NCT04951622) that enrolled adults with gMG who had an insufficient response to ongoing standard of care therapy. Participants were randomly assigned to receive nipocalimab (n=98) or placebo (n=98) by IV infusion q2wks. Primary efficacy endpoint was the comparison of the mean change from baseline to weeks 22, 23, and 24 between treatment groups in the Myasthenia Gravis-Activities of Daily Living (MG-ADL) total score.

The primary efficacy analysis population included 153 patients. At baseline, the median MG-ADL and Quantitative Myasthenia Gravis (QMG) total scores were 9 and 15, respectively; 88% of participants were positive for AChR antibodies and 10% were positive for MuSK antibodies.

At week 24, the nipocalimab group experienced a a statistically significant improvement in MG-ADL total score compared with the placebo group (-4.7 vs -3.3; least squares [LS] mean difference, -1.5 [95% confidence interval [CI], -2.4, -0.5; P =.002). The nipocalimab group also showed a statistically significant difference in QMG total score change from baseline vs. placebo (-4.9 vs -2.1; LS mean difference, -2.8; 95% CI, -4.2, -1.4; P <.001).

Safety

The most common adverse reactions (≥10%) in patients with gMG treated with Imaavy were respiratory tract infections, peripheral edema, and muscle spasms.

Recommended dose

The recommended initial dosage of Imaavy is 30 mg/kg once via IV infusion over at least 30 minutes. Two weeks after the initial dosage, administer a maintenance dosage of 15 mg/kg via IV infusion over at least 15 minutes, and continue q2wks thereafter.

Sources:

Imaavy (nipocalimab-aahu) [package insert]. U.S. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/761430s000lbl.pdf Revised April 2024. Accessed May 2, 2025.

Johnson & Johnson receives FDA approval for Imaavy™ (nipocalimab-aahu), a new FcRn blocker offering long-lasting disease control in the broadest population of people living with generalized myasthenia gravis (gMG). [News Release]. 2025. https://www.jnj.com/media-center/press-releases/johnson-johnson-receives-fda-approval-for-imaavytm-nipocalimab-aahu-a-new-fcrn-blocker-offering-long-lasting-disease-control-in-the-broadest-population-of-people-living-with-generalized-myasthenia-gravis-gmg