Amgen reports positive late-stage results for Uplizna in generalized myasthenia gravis

Amgen has announced encouraging top-line results from a Phase 3 clinical trial of its investigational B cell-depleting therapy, Uplizna (inebilizumab-cdon), aimed at treating adults with generalized myasthenia gravis (gMG). The MINT trial has been assessing the efficacy and safety of Uplizna in patients with both acetylcholine receptor autoantibody-positive and muscle-specific kinase autoantibody-positive gMG.

Generalized myasthenia gravis is a rare autoimmune disorder that affects up to 100,000 people in the United States. It interrupts neuromuscular communication, leading to muscle weakness. Approximately 85% of myasthenia gravis cases are classified as generalized, and the condition is more prevalent in women aged 20 to 30 and men aged 50 and older. Symptoms of gMG include difficulty breathing, swallowing, and impaired speech and vision.

The results from the MINT trial were presented at the American Association of Neuromuscular and Electrodiagnostic Medicine Annual Meeting. The findings showed a statistically significant improvement from baseline in the Myasthenia Gravis Activities of Daily Living score for patients treated with Uplizna compared to those receiving a placebo at the 26-week mark. This outcome met the primary endpoint of the study.

Beyond the primary endpoint, Uplizna also exhibited statistically significant and clinically meaningful improvements from baseline compared to placebo for several secondary endpoints. One key secondary endpoint was the change in the Quantitative Myasthenia Gravis score at week 26 for the combined patient population.

Amgen outlined that participants who started the study on corticosteroids began reducing their dosage from the fourth week, aiming to reach a dose of 5mg per day of prednisone by the 24th week. Importantly, no new safety issues were identified throughout the trial.

Jay Bradner, Amgen’s executive vice president for research and development and chief scientific officer, emphasized the importance of providing effective long-term treatment options for patients with gMG. He highlighted that the significant clinical results from the MINT trial add to the growing body of evidence supporting Uplizna's potential in managing severe autoimmune diseases.

Amgen intends to seek U.S. approval for Uplizna for this particular indication and then expand to other major markets. Currently, Uplizna is already approved for treating certain adults with neuromyelitis optica spectrum disorder, another rare autoimmune condition that targets the optic nerve, spinal cord, brain, and brainstem.