The Muscular Dystrophy Association (MDA), an organisation committed to transforming the lives of people living with muscular dystrophy, ALS, and related neuromuscular diseases, is celebrating the decision by the US Food and Drug Administration (FDA) to offer accelerated marketing approval to casimersen (Amondys 45) intended for the treatment of Duchenne muscular dystrophy (DMD) in patients amenable to skipping exon 45, it was reported on Thursday.

The product is the fourth exon-skipping, disease-modifying drug to treat DMD. It will be offered in the US and marketed by Sarepta Therapeutics.

This development highlights the importance of years of commitment to supporting and funding breakthrough research by the MDA and others into gene identification and unlocking the cause of DMD.

The US FDA's decision to grant accelerated approval to Amondys 45 was based on positive results from a global, randomised, double-blind, placebo-controlled phase three clinical trial (ESSENCE) that is assessing the efficacy and safety of the drug in patients with DMD amenable to skipping exon 45. The current approval is based on findings that AMONDYS 45 has met the full statutory standards for safety and effectiveness and demonstrated an increase in dystrophin production in skeletal muscle of patients amenable to exon 45 skipping. Continued approval may be contingent upon verification of a clinical benefit in confirmatory trials.