FDA Approves Santhera’s Agamree for Duchenne Muscular Dystrophy

Rare Daily Staff

The U.S. Food and Drug Administration has approved Santhera Pharmaceuticals’ Agamree for use in treating Duchenne muscular dystrophy in patients aged two years and older.

Duchenne muscular dystrophy (DMD), the most common form of muscular dystrophy, is a rare and life-threatening neuromuscular disorder characterized by progressive muscle dysfunction, ultimately leading to loss of ambulation, respiratory failure, and fatality. Current standard treatment for DMD involves corticosteroids, which often come with significant side effects. It is estimated that between 11,000 and 13,000 patients in the United States are affected by DMD, with approximately 70 percent of patients currently receiving concomitant corticosteroid treatment.

Agamree (vamorolone) mode of action is based on differential effects on glucocorticoid and mineralocorticoid receptors and modifying further downstream activity and, as such, is considered a novel corticosteroid with dissociative properties in maintaining efficacy, with a better-tolerated side effect profile. This mechanism of action may allow vamorolone to emerge as an effective alternative to the current standard of care corticosteroids in children, adolescents, and adult patients with DMD.

In the pivotal VISION-DMD study, vamorolone met the primary endpoint Time to Stand (TTSTAND) velocity versus placebo at 24 weeks of treatment and showed a good safety and tolerability profile. The most commonly reported adverse events versus placebo from the VISION-DMD study were cushingoid features, vomiting, and vitamin D deficiency. Adverse events were generally of mild to moderate severity.

In July 2023, Catalyst Pharmaceuticals secured the exclusive North American license and commercial rights for Agamree from Santhera for DMD and other potential indications. As part of that transaction, Santhera will promptly transfer the approved New Drug Application for Agamree to Catalyst.

FDA’s approval of Agamree was based on the data from the pivotal phase 2b VISION-DMD study as supplemented with safety information collected from three open-label studies, including extension studies. In these trials, Agamree was administered at doses ranging from 2 to 6 mg/kg/day, extending for a period of up to 48 months. Compared with current standard-of-care corticosteroids, this novel corticosteroid treatment exhibited comparable efficacy, with data suggesting a reduction in adverse events, notably related to bone health, growth trajectory, and behavior.

“We strongly believe that this novel steroid has the transformational potential to make a significant difference for patients living with Duchenne muscular dystrophy and potentially other chronic inflammatory diseases,” said Patrick McEnany, chairman and CEO of Catalyst Pharmaceuticals.

Catalyst plans to launch Agamree in the first quarter of 2024. Agamree was granted Orphan Drug and Rare Pediatric Disease designations status for DMD in the U.S. and will be eligible for seven years of orphan drug exclusivity upon approval date.

Photo: Patrick McEnany, chairman and CEO of Catalyst Pharmaceuticals