FDA Approves Inebilizumab-cdon (Uplizna) for Generalized Myasthenia Gravis

The US Food and Drug Administration has approved Amgen’s inebilizumab-cdon (Uplizna) for the treatment of generalized myasthenia gravis (gMG) in adults who are anti-acetylcholine receptor (AChR) and anti-muscle specific tyrosine kinase (MuSK) antibody positive, offering patients a new targeted treatment option that has the potential for long-term disease control with just 2 doses a year after 2 initial loading doses.1

As described in a December 11, 2025, release from the Company, the approval marks inebilizumab-cdon’s third indication and is supported by data from the Myasthenia Gravis Inebilizumab Trial (MINT), the largest phase 3 biologic study to include both AChR+ and MuSK+ patients, and the first to successfully incorporate a steroid taper into its protocol.1

"Managing a rare and chronic illness can mean facing unpredictable relapsing symptoms and demanding treatment schedules," Samantha Masterson, president and chief executive officer of the Myasthenia Gravis Foundation of America, said in a statement.1 "This approval marks an important milestone, offering durable efficacy and a dosing schedule that provides people living with generalized myasthenia gravis 6 months of treatment-free time between maintenance doses."

Inebilizumab-cdon is a humanized monoclonal antibody (mAb) that causes targeted and sustained depletion of key cells that contribute to underlying disease process (autoantibody-producing CD19+ B cells, including plasmablasts and some plasma cells). It has previously been approved by the FDA for the treatment of adult patients with anti-aquaporin-4 (AQP4) antibody positive neuromyelitis optica spectrum disorder (NMOSD) in June 2020, and for the treatment of adult patients with Immunoglobulin G4-related disease (IgG4-RD) in April 2025.1

MINT is a randomized, double-blind, placebo-controlled, parallel-group trial designed to evaluate the efficacy and safety of inebilizumab-cdon in adults with gMG. The trial enrolled 238 adults with gMG, including 190 patients who are AChR+ and 48 patients who are MuSK+.1

The primary endpoint was change from baseline in MG-ADL score at week 26 in the combined study population. Key secondary endpoints included change from baseline in QMG scores in the combined study population; change from baseline in MG-ADL score at week 26 for the AChR+ cohort and separately the MuSK+ cohort; and change from baseline in QMG score at Week 26 for the AChR+ cohort and separately the MuSK+ cohort. MINT also includes an optional 3-year open-label treatment period.1,2

In MINT, at week 26, inebilizumab-cdon demonstrated a 1.9-point difference in the MG-ADL score compared with placebo (-4.2 vs -2.2; P <.0001). Benefits in the AChR+ patient subgroup continued through week 52, the longest randomized-controlled period for a phase 3 trial in gMG, with an exploratory analysis of AChR+ patients showing a 2.8-point difference in MG-ADL for inebilizumab-cdon compared with placebo (-4.7 vs -1.9; 95% CI, −3.9 to −1.7).1,2

"[Inebilizumab-cdon] 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 Nowak, MD, MS, global principal investigator and director of the Myasthenia Gravis Clinic at Yale University.1 "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."

References

1. Amgen. FDA APPROVES UPLIZNA® FOR ADULTS WITH GENERALIZED MYASTHENIA GRAVIS. 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. Nowak RJ, Benatar M, Ciafaloni M, et al. A Phase 3 Trial of Inebilizumab in Generalized Myasthenia Gravis. N Eng J Med. doi:10.1056/NEJMoa250156