BioMarin Completes Rolling NDA Submission to FDA for Drisapersen for Treatment of Duchenne Muscular Dystrophy Amenable to Exon 51 Skipping

BioMarin Pharmaceutical Inc.

today announced completion of the rolling submission of a New Drug Application (NDA) to the United States Food and Drug Administration (FDA) for drisapersen, an investigational exon-skipping drug candidate for the treatment of the largest genetically defined subset of Duchenne muscular dystrophy (DMD). DMD is the most common fatal genetic disorder diagnosed in childhood, affecting approximately 1 in every 3,500 live male births with about 20,000 new cases diagnosed globally each year. Drisapersen induces the skipping of dystrophin exon 51, potentially providing a therapeutic benefit to DMD patients for whom skipping of exon 51 restores the proper dystrophin reading frame, corresponding to approximately 13% of DMD patients. The company intends to also submit an application for registration in the European Union in summer 2015. "We believe drisapersen may offer a meaningful benefit to boys living with DMD whose mutations are amenable to exon 51 skipping. The totality of data on drisapersen contains three randomized, placebo-controlled, efficacy trials and two long term extension studies, which include some boys treated for approximately 3.4 years," said Camilla V. Simpson, Global Head of Regulatory Affairs, Pharmacovigilance. "With this application, BioMarin continues in its long-standing tradition of developing important therapies for those who are most in need. The submission of the NDA represents a significant milestone for BioMarin, and we appreciate the strong, collaborative effort of many hard working employees, investigators, patients and their families. We look forward to working with the U.S. Regulatory Authorities to thoroughly understand the data generated for this heterogenous and critically ill patient population and hopefully to bring this treatment to patients expeditiously." Drisapersen has been granted Orphan and Fast Track status, as well as Breakthrough Therapy designation by the FDA. DMD is caused by a mutation in the gene that encodes for dystrophin, a protein that is important in connecting the cytoskeleton of muscle fibers to the extracellular matrix. Its deficiency in DMD leads to progressive muscle weakness, loss of ambulation in early adolescence, and typically death due to pulmonary or cardiac insufficiency in the late twenties. Because the Duchenne gene is found on the X-chromosome, it primarily affects boys; however, it occurs across all races and cultures. There is currently no approved therapy in the United States for DMD. "This is a first for the Duchenne community, and we are filled with hope that there could be a treatment for Duchenne in the United States," said Debra Miller, co-founder and CEO of CureDuchenne. "CureDuchenne has been supporting the development of drisapersen for more than a decade, and we are delighted that BioMarin has reached this important stage. We salute the researchers who have been working so hard, and we share their determination to find a cure for Duchenne."