BUSINESS OVERVIEW 6 and Chairman of the Department of Ophthalmology at the Centre 6.2 Hospitalier National d’Ophtalmologie des XV-XX in Paris, France. OUR PRODUCT DEVELOPMENT PIPELINE Since July 2016, Dr. Sahel has also been the Chairman of the Department of Ophthalmology at the Brain Institute at the Our pipeline is comprised of two lead product candidates for the University of Pittsburgh. Such experience plays a critical role treatment of sight-threatening retinal degenerative diseases, in our core MTS and optogenetics technology platforms and together with preclinical development programs targeting reflects substantial cross-disciplinary knowledge. ophthalmic and neurodegenerative diseases. Below is a table summarizing our development programs: Subject to the successful completion of clinical trials, we currently system through the development and commercialization of novel expect to file for regulatory approval for GS010 in Europe and therapies by combining gene therapy-based approaches with our in the United States in the second quarter of 2019. Depending proprietary MTS and optogenetics technology platforms. The key on the progress of our interactions with regulatory authorities, elements of our strategy are the following: GS010 could then potentially be in a position to be approved in • Complete clinical development and obtain regulatory the fourth quarter of 2019, with possible first commercialization in approval for our lead product candidate, GS010, for the 2020, subject however to a variety of factors, including changes in treatment of LHON. regulatory requirements, evolutions in guidance from the FDA, the EMA or other European regulatory authorities, and the occurrence Our two most advanced ongoing Phase I I I clinical trials of GS010 of unexpected events in the approval process, preparation for for the treatment of LHON, RESCUE and REVERSE, have commercialization or otherwise, any of which could impact our enrol led 76 subjects and we expect to report top-line results anticipated timeline and our ability to obtain regulatory approval of these trials in 2018. Upon completion of these two trials, if and commercialize GS010. For a description of such factors, see successful, we intend to meet with the FDA and apply for Fast Section 4 “Risk Factors” of this Registration Document. Track Designation, which, if granted, would allow us to file a BLA and seek an accelerated approval pathway. In addition, we expect that the results of our Phase I I I RESCUE and REVERSE trials, 6.3 if successful, wil l be sufficient to support filing for marketing OUR STRATEGY authorization in the European Union. GS010 has received orphan drug designation for the treatment of LHON in the United States Our goal is to transform the lives of patients suffering from and the European Union. We believe that GS010 has the potential severe degenerative diseases of the eye and central nervous to be the first FDA-approved therapy for LHON. 68 – GENSIGHT BIOLOGICS – 2017 Registration Document