The Food and Drug Administration (FDA) has approved inebilizumab-cdon for adults with generalized myasthenia gravis (MG) who are positive for anti-acetylcholine receptor or anti-muscle specific tyrosine kinase antibodies, giving patients a new option aimed at longer-lasting symptom control with fewer infusions, according to a press release published recently. The drug is made by Amgen and will be marketed under the brand name Uplizna.
Inebilizumab, a monoclonal antibody, works by targeting CD19-positive B cells, including cells producing the antibodies that drive MG. It is the first CD19-directed B cell therapy approved for this condition. After two initial loading doses, treatment is given just twice a year. For patients, this schedule may mean fewer clinic visits and longer periods without treatment interruptions.
“Managing a rare and chronic illness can mean facing unpredictable relapsing symptoms and demanding treatment schedules,” said Samantha Masterson, president and chief executive officer of the Myasthenia Gravis Foundation of America. “This approval marks an important milestone, offering durable efficacy and a dosing schedule that provides people living with generalized myasthenia gravis six months of treatment-free time between maintenance doses.”
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The approval is based on results from the Phase 3 Myasthenia Gravis Inebilizumab Trial, known as MINT, which enrolled 238 adults. At 26 weeks, patients receiving inebilizumab had a 1.9-point greater improvement on the Myasthenia Gravis Activities of Daily Living (MG-ADL) scale than those given placebo, a statistically significant difference. This scale measures how symptoms affect everyday tasks such as chewing, walking and breathing.
The study also included a planned reduction in steroid use, reflecting real-world concerns about long-term steroid side effects. By week 26, 87.4% of patients treated with inebilizumab and 84.6% of those on placebo had reduced prednisone to 5 mg per day or less. In patients with anti-AChR antibodies, improvements in daily function continued through 52 weeks.
The most common side effects seen in patients with generalized MG were headache and infusion-related reactions. Inebilizumab was previously approved for neuromyelitis optica spectrum disorder in 2020 and IgG4-related disease in 2025. For patients with generalized MG, this approval adds a treatment option that may offer sustained symptom relief, less frequent dosing and the potential to lower reliance on steroids.
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