Phase III Trial Data Show Uplizna Significantly Improves Symptoms of Acetylcholine Receptor Autoantibody-Positive Generalized Myasthenia Gravis

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Results from the Phase III MINT trial show that a twice-yearly dosing regimen of Uplizna (inebilizumab-cdon; Amgen) significantly improved symptoms of patients with acetylcholine receptor autoantibody (AChR)-positive generalized myasthenia gravis (gMG) over 52 weeks. According to the study, the treatment demonstrated a greater reduction in Myasthenia Gravis Activities of Daily Living (MG-ADL) scores compared to placebo at week 26 and sustained efficacy through week 52.

"The 52-week MINT trial results highlight the potential for a new standard of care in gMG, offering durable symptom relief with a simplified treatment regimen," said Jay Bradner, MD, EVP, Research and Development at Amgen, in a press release. "These findings reinforce Uplizna's ability to provide sustained symptom relief with just two doses per year—an important advancement for patients living with generalized myasthenia gravis—while underscoring our commitment to developing transformative therapies for people facing complex autoimmune diseases."

The randomized, double-blind, placebo-controlled, parallel-group MINT trial assessed the efficacy and safety of Uplizna in 238 adults with gMG, including 190 patients who are AChR-positive and 48 patients who are muscle-specific kinase autoantibody (MuSK)-positive. The primary endpoint of the study was the change from baseline in MG-ADL scores at week 26 in the combined population. Secondary endpoints included changes in Quantitative Myasthenia Gravis (QMG) scores and the change from baseline in MG-ADL scores at week 26 for the AChR-positive and MuSK-positive cohorts.

The data revealed that patients treated with Uplizna experienced a mean improvement of -4.2 in MG-ADL scores compared to -2.2 in the placebo group (p<0.0001). By week 52, the adjusted difference in MG-ADL scores between Uplizna and placebo was -2.8, with 72.3% of treated patients achieving a ≥3-point improvement, compared to 45.2% in the placebo group. Additionally, Uplizna demonstrated a superior QMG score, with an adjusted difference of -4.3 at week 52, and 69.2% of treated patients achieving at least a three-point improvement compared to 41.8% with a placebo.

Common adverse events (AEs) included infusion-related reactions, nasopharyngitis, and urinary tract infections. No new safety signals were identified, and the overall treatment-related AE profile remained consistent with Uplizna’s known safety profile from its previously approved indication.

According to the Myasthenia Gravis Foundation of America, myasthenia gravis (MG) affects approximately 37 out of every 100,000 people in the United States. Additionally, an estimated 150 to 200 out of every million people globally are affected by the condition. Data from 2021 suggests that the number of people living with MG is increasing, likely due to longer life expectancy and improved diagnostic tools.

MG can be diagnosed at any age; however, it is most common in women under 50 years of age and in men over 65. Generally, the condition is most prevalent in individuals over 50 years of age. MG affects people of all racial and ethnic backgrounds, though it appears to be slightly more common among people of African descent. Studies suggest that certain aspects of the condition may differ by ethnicity. For instance, African American individuals are more likely to be diagnosed at a younger age and are more likely to have MuSK antibodies compared to Caucasian individuals.²

Uplizna is already approved for the treatment of neuromyelitis optica spectrum disorder and is currently under FDA priority review for Immunoglobulin G4-related disease. It has also been granted Orphan Drug Designation for gMG, with regulatory filings expected to be completed in the first half of 2025.¹

"I'm looking forward to further examining the 52-week MINT data with my colleagues in the neurology community at AAN," global principal study investigator Richard J. Nowak, MD, MS, director of the Myasthenia Gravis Clinic at Yale University, said in the press release. "These results showed that Uplizna consistently relieved burdensome symptoms and improved activities of daily living for gMG patients."

References

1. UPLIZNA® (INEBILIZUMAB-CDON) SIGNIFICANTLY IMPROVES GENERALIZED MYASTHENIA GRAVIS SYMPTOMS IN ACETYLCHOLINE RECEPTOR AUTOANTIBODY-POSITIVE PATIENTS OVER 52 WEEKS. Amgen. March 13, 2025. Accessed March 14, 2025. https://www.amgen.com/newsroom/press-releases/2025/03/uplizna-inebilizumabcdon-significantly-improves-generalized-myasthenia-gravis-symptoms-in-acetylcholine-receptor-autoantibodypositive-patients-over-52-weeks?_gl=1*1qf4n6a*_up*MQ..*_ga*MTg0MzMzMzIyNC4xNzQxOTU1MjQ5*_ga_CBMSV0J9VL*MTc0MTk1NTI0OC4xLjEuMTc0MTk1NTI2MS4wLjAuMA

2. Overview of MG. Myasthenia Gravis Foundation of America. Accessed March 14, 2025. https://myasthenia.org/understanding-mg/overview-mg/