FDA Approves Uplizna for Antibody-Positive Generalized Myasthenia Gravis
The Food and Drug Administration (FDA) has approved Uplizna (inebilizumab-cdon; Amgen, Thousand Oaks, CA) for the treatment of generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor or anti-muscle-specific tyrosine kinase antibody positive (AChR+ or MuSK+). The medication was originally approved in 2020 for the treatment of people with neuromyelitis optica spectrum disorder (NMOSD). The FDA’s decision to expand the indication for Uplizna was based on phase 3 data from the MINT clinical trial (NCT04524273), which showed clinically meaningful improvements in myasthenia-specific disability scales in those treated with the drug vs placebo. According to a statement released by Amgen, Uplizna is now the first and only CD19-targeted B cell therapy approved for AChR+ and MuSK+ individuals with gMG.
MINT (NCT04524273) was a randomized, double-blind, placebo-controlled, parallel-group study that included 238 adults with gMG who were using corticosteroids and/or nonsteroidal immunosuppressive therapy (IST), including 190 AChR+ and MuSK+ participants. Participants were randomized to receive IV Uplizna or placebo. The primary end point was change from baseline in Myasthenia Gravis Activities of Daily Living (MG-ADL) score at week 26 in the combined population. Key secondary end points included change in Quantitative Myasthenia Gravis (QMG) score and prespecified analyses in the AChR+ and MuSK+ subgroups. The protocol incorporated a structured steroid taper and included an optional 3-year open-label extension (OLE).
Key findings from MINT included the following:
- Primary End Point Met: In the combined population at week 26, compared with placebo, Uplizna treatment was associated with a 1.9-point improvement in MG-ADL score (-4.2 vs -2.2; P<.0001).
- In the combined population at week 26, Uplizna-treated participants showed a 2.5-point difference in QMG score over those who received placebo (-4.8 vs -2.3; P=.0002).
- At week 26 in AChR+ participants, Uplizna treatment led to a 1.8-point MG-ADL score improvement (-4.2 vs -2.4; P=.0015) and a 2.5-point QMG score improvement (-4.4 vs -2.0; P=.0011) vs placebo.
- At week 26 in MuSK+ participants, Uplizna treatment improved MG-ADL score by 2.2 points vs placebo (-3.9 vs -1.7; P=.0297), while the 2.3-point QMG score difference (-5.2 vs -3.0; P=.1326) was not statistically significant.
- Exploratory analyses in the AChR+ subgroup showed sustained benefit through week 52, with a 2.8-point MG-ADL difference (-4.7 vs -1.9) and a 4.3-point QMG difference (-5.8 vs -1.4) favoring Uplizna.
- By week 26, 87.4% of participants receiving Uplizna and 84.6% receiving placebo had tapered to prednisone 5 mg or less per day.
- The most common adverse reactions in gMG were headache and infusion-related reactions.
“Uplizna showed strong efficacy at 26 weeks in both AChR+ and MuSK+ patients, with AChR+ patients continuing to improve through 52 weeks in MINT,” said Richard J. Nowak, MD, MS, Global Principal Investigator and Director of the Myasthenia Gravis Clinic at Yale University. “MINT also uniquely required steroid tapering, recognizing that long-term steroid use adds to the overall burden of disease. This approval brings a new first-in-class approach to gMG, expanding treatment options for clinicians and patients.”
Source: Amgen. FDA approves Uplizna for adults with generalized myasthenia gravis. PR Newswire. Published 11 December, 2025. Accessed 12 December, 2025. https://prnmedia.prnewswire.com/news-releases/fda-approves-uplizna-for-adults-with-generalized-myasthenia-gravis-302639699.html