Business Description

Overview We are a commercial-stage biopharmaceutical company focused on helping patients through the discovery and development of unique RNA-targeted therapeutics, siRNA knockdown therapies, gene therapy and other genetic therapeutic modalities for the treatment of rare diseases. Applying our proprietary, differentiated and innovative technologies, and through collaborations with our strategic partners, we have developed multiple approved products for the treatment of Duchenne muscular dystrophy ("Duchenne") and are developing potential therapeutic candidates for a broad range of diseases and disorders, including Duchenne and LGMD. We are also developing potential therapeutic candidates through our partnered program with Arrowhead for the treatment of Facioscapulohumeral muscular dystrophy ("FSHD"), myotonic dystrophy type 1 (“DM1”), Spinocerebellar ataxia ("SCA"), Idiopathic Pulmonary Fibrosis ("IPF"), Huntington's disease and other neuromuscular and skeletal diseases. To date, we have developed and commercialized the following four approved products for the treatment of Duchenne: EXONDYS 51 (eteplirsen) Injection (“EXONDYS 51”), VYONDYS 53 (golodirsen) Injection (“VYONDYS 53”), AMONDYS 45 (casimersen) Injection (“AMONDYS 45”), and ELEVIDYS. Each of these approved products, and the indications for which they have been approved for, is described under the heading “Our Commercial Products” in this Item 1. Objectives and Business Strategy We believe that our proprietary technology platforms and collaborations can be used to develop novel pharmaceutical products to treat a broad range of diseases and address key currently-unmet medical needs. We intend to leverage our technology platforms, organizational capabilities, collaborations and resources to lead the field of precision genetic medicines, including the treatment of rare, neuromuscular and other diseases, with a diversified portfolio of product candidates. In pursuit of this objective, we intend to focus on the following activities: • investing in next-generation precision medicine, including our siRNA programs, through internal research, strategic partnerships, collaborations and other potential opportunities; • advancing our RNA technologies, launching potential approved products and supporting commercialization of approved products; • advancing our gene therapy pipeline, including developing gene therapy product candidates, operationalizing our manufacturing strategy and furthering our commercial capabilities in preparation for potential regulatory approvals; and • continuing to nurture our culture, which is based on strong patient focus, bias to action, a self-starter mentality, smart and appropriate risk-taking and high ethics. Technology and Platforms • Exon skipping is intended to promote the production of an internally truncated but functional dystrophin protein. The original PMO structure and variations of this structure that are so-called PMO-based (collectively “PMO-based”) are central to our proprietary chemistry platform. PMO technologies can be used to selectively up-regulate or down-regulate the production of a target protein through pre-mRNA splice alteration. PMO-based compounds have the potential to be designed to create more, less, or none of certain proteins, or produce analogues of endogenous proteins. This technology can be used to correct disease-causing genetic errors by inducing the targeted expression of novel proteins. • Our siRNA programs make use of Arrowhead’s targeted RNAi molecule platform and are designed to deliver siRNA to multiple tissue and cell types throughout the body with the goal of initiating the RNA interference mechanism and inducing rapid and durable knockdown of target genes. The platform covers a range of rare diseases, with our leading product candidates including SRP-1003 (DM1) and SRP-1001 (FSHD), each as described below. • As part of our multifaceted approach to Duchenne, we are also developing gene therapy technologies to treat Duchenne. Our gene therapy aims to express a smaller but still functional version of dystrophin. We use a unique adeno-associated virus (“AAV”) vector called AAVrh.74 to transport the transgene – the genetic material that will make the protein of interest – to the target cells. A unique, engineered dystrophin is used because naturally-occurring dystrophin is too large to fit in an AAV.…