Edgewise Therapeutics has announced a significant expansion of its clinical development program for EDG-5506, an investigational oral therapy designed to protect fast-twitch skeletal muscles from contraction-related injuries. The company unveiled the FOX trial, a new Phase 2 study specifically targeting children and adolescent boys aged 6-14 years with Duchenne muscular dystrophy who have previously received gene therapy.
New FOX Trial Targets Gene Therapy Recipients
The FOX trial represents a 12-week placebo-controlled study that will evaluate the safety, pharmacokinetics, and effects on muscle health markers of EDG-5506 in this specific patient population. The study will also assess improvements in physical abilities using the North Star Ambulatory Assessment (NSAA) and measure patient and caregiver-reported outcomes.
Following the initial 12-week controlled period, all participants will have access to EDG-5506 through an open-label extension program, ensuring that even those who received placebo during the initial phase can access the investigational treatment.
Parallel Development in Corticosteroid-Naive Patients
Edgewise is simultaneously investigating EDG-5506's impact in Duchenne patients who haven't used corticosteroids through the LYNX Phase 2 placebo-controlled trial. This study enrolls children aged 4-9 years and aims to determine the optimal dose of EDG-5506 that can reduce muscle damage markers and improve patient outcomes for a future Phase 3 trial.
The LYNX trial, which began enrollment in October 2022, is designed to include 27 children with Duchenne aged 4 to 9 years on stable corticosteroids and/or exon skippers. Interim results from this study are expected in the first half of 2024, with the company planning to initiate a Phase 3 trial using the most effective dose identified in 2024.
Broader Clinical Portfolio in Muscular Dystrophies
Beyond Duchenne, EDG-5506 is being evaluated in the GRAND CANYON pivotal trial for Becker muscular dystrophy. This global study recently began enrollment and is designed to recruit approximately 120 individuals with Becker aged between 18 and 50 years old across up to 50 sites in 10 countries. The treatment period extends for 18 months, representing an expansion of the earlier CANYON Phase 2 study.
The CANYON study has over-enrolled with 39 adults and 24 adolescents with Becker muscular dystrophy, with data anticipated in the second half of 2024. Additionally, the company is conducting the DUNE exercise challenge study, evaluating EDG-5506's effects on biomarkers of muscle damage following exercise in adults with LGMD2I/R9, Becker, or McArdle disease, with results expected in the first half of 2024.
Mechanism and Development Strategy
EDG-5506 is formulated as a small oral pill designed to selectively limit exaggerated muscle damage caused by the absence or loss of functional dystrophin protein. Dystrophinopathies, including Duchenne and Becker muscular dystrophies, are neuromuscular conditions characterized by deficient or missing dystrophin, a protein located within muscle cells that is essential for muscle function.
The company's strategic approach involves testing EDG-5506 across multiple dystrophinopathy populations to establish its therapeutic potential in protecting muscles from contraction-related damage. This comprehensive clinical program positions Edgewise to address significant unmet medical needs across the dystrophinopathy spectrum.
