Sarepta Therapeutics Announces FDA Acceptance of Casimersen (SRP-4045) New Drug Application for Patients with Duchenne Muscular Dystrophy Amenable to Skipping Exon 45 - Seite 2

About Casimersen
Casimersen uses Sarepta’s proprietary phosphorodiamidate morpholino oligomer (PMO) chemistry and exon-skipping technology to skip exon 45 of the Duchenne gene. Casimersen is designed to bind to exon 45 of dystrophin pre-mRNA, resulting in exclusion, or “skipping,” of this exon during mRNA processing in patients with genetic mutations that are amenable to exon 45 skipping. Exon skipping is intended to allow for production of an internally truncated dystrophin protein.

About the ESSENCE Study
The ESSENCE study is a double-blind, placebo-controlled, multi-center Phase 3 study evaluating the efficacy and safety of casimersen (SRP-4045) and golodirsen (SRP-4053, approved as VYONDYS 53). Eligible patients with out-of-frame deletion mutations amenable to exon 45 or 53 skipping are randomized to receive once weekly intravenous (IV) infusions of 30 mg/kg of SRP-4045 or 30 mg/kg of SRP-4053, respectively (combined-active group) or placebo for up to 96 weeks. This is followed by an open-label extension period in which all patients will receive open-label active treatment for 48 weeks, up to week 144 of the study.

Clinical efficacy is being assessed at regularly scheduled study visits, including functional tests such as the six-minute walk test (6MWT). All patients undergo a muscle biopsy at baseline and will undergo a second muscle biopsy either at week 48 or week 96.

Safety is being assessed through the collection of adverse events, laboratory tests, electrocardiograms (ECGs), echocardiograms (ECHOs), vital signs, and physical examinations throughout the study.

About Duchenne Muscular Dystrophy
Duchenne muscular dystrophy is a rare, fatal neuromuscular genetic disease that occurs in approximately one in every 3,500-5,000 males worldwide. Duchenne is caused by a change or mutation in the gene that encodes instructions for dystrophin. Symptoms of Duchenne usually appear in infants and toddlers. Affected children may experience developmental delays such as difficulty in walking, climbing stairs or standing from a sitting position. As the disease progresses, muscle weakness in the lower limbs spreads to the arms, neck and other areas. Most patients require full-time use of a wheelchair in their early teens, and then progressively lose the ability to independently perform activities of daily living such as using the restroom, bathing and feeding. Eventually, increasing difficulty in breathing due to respiratory muscle dysfunction requires ventilation support, and cardiac dysfunction can lead to heart failure. The condition is universally fatal, and patients usually succumb to the disease in their twenties.