FDA gives nod to novel steroid for treatment of Duchenne muscular dystrophy

The US Food and Drug Administration has approved Vamorolone (Agamree), a novel corticosteroid for treatment of Duchenne muscular dystrophy (DMD) in patients ages 2 years and older.

The novel steroidal therapy showed similar efficacy to traditional corticosteroids in treating Duchenne with fewer negative downstream effects related to bone health and growth trajectory.

"Corticosteroids have been a first line treatment for DMD for many years but their utility has always been limited by the side effect profile, which includes weight gain, short stature, and decreased bone density, among others," Sharon Hesterlee, PhD, chief research officer of the Muscular Dystrophy Association (MDA), said in a news release.

AGAMREE offers a novel corticosteroid treatment option for DMD, addressing a significant unmet medical need. In July 2023, Catalyst secured the exclusive North American license and commercial rights for AGAMREE from Santhera for DMD and other potential indications, bolstering its neuroscience commercial portfolio with a highly synergistic neuromuscular asset. 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. The approval of AGAMREE underscores the potential of reshaping the DMD treatment paradigm for this life-threatening rare disease. The addition of AGAMREE expands our rare neuromuscular disease portfolio, and we look forward to executing on our proven commercial capabilities to bolster our long-term growth potential,” said Patrick J. McEnany, Chairman and CEO of Catalyst Pharmaceuticals. “Our unwavering commitment extends beyond this important milestone as we are resolute in our mission to ensure that DMD patients in the U.S. have access to this treatment option as we believe that AGAMREE may offer the potential of increasing the duration of ambulation and mobility in these patients, thereby significantly improving their overall quality of life. We expect to launch the product in the first quarter of 2024. At that time, we will introduce a comprehensive financial assistance program aimed at helping ensure accessibility and minimizing patient co-pays and deductibles, thereby enhancing affordability for all DMD patients. We look forward to successfully commercializing this product with a continued commitment to serving our patient communities."

Upon the transfer of AGAMREE's NDA into its neuromuscular franchise, Catalyst will harness its product portfolio synergies by leveraging its well-established expertise and proven commercial capabilities. The Company plans to launch the product in Q1 2024, spearheaded by its seasoned and experienced U.S. commercial and medical affairs neuromuscular teams.

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 and has issued pending patents that could provide protection until 2040.

About Duchenne Muscular Dystrophy (DMD)

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 U.S. are affected by DMD, with approximately 70% of patients currently receiving concomitant corticosteroid treatment.

About AGAMREE® (vamorolone)

AGAMREE's unique 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 (p=0.002) 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.

AGAMREE was granted U.S FDA approval on October 26, 2023, and was granted Orphan Drug and Rare Pediatric Disease designations status for DMD in the U.S. and making it eligible for seven years of orphan drug exclusivity upon approval. AGAMREE also has issued and pending patents that could provide protection until 2040. In Europe, it has received Promising Innovative Medicine (PIM) status from the UK MHRA for DMD.