The FDA has approved Amgen’s Uplizna (inebilizumab-cdon) for adults with generalized myasthenia gravis (gMG) who test positive for AChR or MuSK antibodies.

New CD19-Targeted Therapy Gains FDA Clearance for Generalized Myasthenia Gravis

The regulatory action adds a new targeted therapy for patients with the rare autoimmune condition, offering a twice-yearly maintenance regimen following two loading doses.¹

"This approval marks a significant advancement for people living with gMG," Jay Bradner, MD, executive vice president of Research and Development at Amgen, said in a press release. "By selectively targeting CD19-positive B cells, Uplizna offers a new approach to treatment that addresses a biological root cause of disease. Uplizna is conveniently dosed twice a year and delivers durable efficacy, helping people manage debilitating symptoms that can compromise daily function—including trouble breathing, speaking and seeing."¹

Overview of Uplizna’s Mechanism and Prior Indications

Uplizna is a humanized, afucosylated IgG1 kappa monoclonal antibody that was designed to target CD19 to induce rapid, deep, and durable B-cell depletion. The medication was previously approved to treat neuromyelitis optica spectrum disorder in adults who are anti-aquaporin-4 antibody positive and was approved for patients with immunoglobulin G4-related disease.

Phase III MINT Trial Design and Patient Population

The latest approval for Uplizna was based on findings from the Phase III MINT trial (NCT04524273), which evaluated Uplizna across both major antibody subtypes and incorporated a required steroid taper into its design.²

• The double-blind, randomized, placebo-controlled MINT trial enrolled 238 patients with gMG who had anti–acetylcholine receptor antibodies or anti–muscle-specific kinase antibodies.
• Participants were randomly assigned in a 1:1 ratio to receive Uplizna administered intravenously at a dose of 300 mg on days one and 15 for all patients in the trial, as well as on day 183 for acetylcholine receptor antibody–positive patients; or matching placebo for 52 weeks in acetylcholine receptor antibody–positive patients or 26 weeks in muscle-specific kinase antibody–positive patients.
• Beginning at week four, treatment with glucocorticoids was tapered to a target dose of 5 mg per day by week 24.
• The trial’s primary endpoint was change from baseline in Myasthenia Gravis Activities of Daily Living scale (MG-ADL) score at week 26 in the combined cohorts of patients who are acetylcholine receptor antibody–positive and muscle-specific kinase antibody–positive.
• A key secondary endpoint was change from baseline in Quantitative Myasthenia Gravis scale (QMG) score at week 26 in the combined patient population.

Clinical Outcomes and Safety Results From the MINT Study

Results from the trial published in April in The New England Journal of Medicine show that Uplinza achieved significant clinical improvements in patient- and clinician-assessed outcomes with a tolerable safety profile.³

• Patients administered Uplizna experienced a higher decrease in MG-ADL score compared with the placebo cohort at week 26 (least-squares mean change, −4.2 vs. −2.2; adjusted difference, −1.9; 95% confidence interval [CI], −2.9 to −1.0; P<0.001).
• Patients in the Uplizna cohort also experienced a higher decrease in QMG score compared to the placebo cohort (least-squares mean change, −4.8 vs. −2.3; adjusted difference, −2.5; 95% CI, −3.8 to −1.2; P<0.001).
• In terms of safety, both cohorts experienced similar incidence of treatment-related adverse events (AEs); however, a higher number of unique AEs were reported in the Uplizna cohort.
• The most frequently reported AEs among patients administered Uplizna were headache, cough, nasopharyngitis, infusion-related reactions, and urinary tract infections.
• Uplizna was not associated with a higher incidence of serious AEs.

Expert Perspective on Uplizna’s Role in gMG Management

"Uplizna showed strong efficacy at 26 weeks in both AChR-positive and MuSK-positive patients, with AChR-positive patients continuing to improve through 52 weeks in MINT," global principal investigator Richard J. Nowak, MD, MS, director of the Myasthenia Gravis Clinic at Yale University, said in the release. "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."¹

References

1. FDA Approves Uplizna® for Adults with Generalized Myasthenia Gravis. News release. Amgen. December 11, 2025. Accessed December 12, 2025. https://www.amgen.com/newsroom/press-releases/2025/12/fda-approves-uplizna-for-adults-with-generalized-myasthenia-gravis

2. Myasthenia Gravis Inebilizumab Trial (MINT). ClinicalTrials.gov. Updated February 20, 2025. Accessed December 12, 2025. https://clinicaltrials.gov/study/NCT04524273

3. Nowak R., et al. A Phase 3 Trial of Inebilizumab in Generalized Myasthenia Gravis. N Engl J Med 2025. DOI: 10.1056/NEJMoa2501561.