BUSINESS OVERVIEW 6 Additional Studies 6.6 We are also conducting a registry study to further advance present OUR SECOND PRODUCT CANDIDATE: GS030 knowledge of the natural history of LHON and its socio-economic FOR THE TREATMENT OF PHOTORECEPTOR impact on subjects affected. This study evaluates the natural DEGENERATION history of vision loss associated with genetic, sociodemographic, We are leveraging our optogenetics technology platform to develop and/or environmental factors that may play a role in phenotypic GS030 for the treatment of diseases of photoreceptor degeneration expression of LHON as current knowledge of factors contributing that include RP, dry AMD and GA. Our most advanced clinical to the LHON phenotype is limited. program using our optogenetics platform is for the treatment Regulatory Interaction for GS010 of RP, which is an orphan family of diseases caused by multiple In October 2014, we initiated our first discussions with the FDA mutations in over 100 genes involved in the visual cycle. There is regarding the prerequisites for future initiation of clinical trials incurrently no existing treatment for RP. GS030 has received orphan the United States. In June 2015, we submitted an application in drug designation for the treatment of RP in the United States and the United States, which was cleared by the FDA on August 19, the European Union and advanced therapy medicinal product, or 2015. ATMP, classification for the treatment of RP in the European Union. We are currently conducting a Phase I/I I clinical trial in end stage, Following our meetings with the FDA in April and December 2016, non-syndromic RP subjects and expect to treat the first subject in the FDA made recommendations with respect to our RESCUE the second quarter of 2018. We anticipate receiving interim data and REVERSE studies, as well as the bilateral treatment of LHON within one year after the last subject is treated. Upon evidence of subjects. Based on these recommendations, a special protocol clinical proof of concept in RP and demonstration of our approach, assessment, or SPA, of a bilateral clinical protocol was submitted we believe this technology would be immediately transferable to to the FDA in July 2017 for subjects with vision loss due to the any disease in which photoreceptors are lost while RGCs remain, ND4 mutation. The design and planned analysis of the REFLECT such as dry AMD and GA. Given this, we expect to initiate clinical protocol (GS-LHON-CLIN-05) testing the safety and efficacy of trials of GS030 for the treatment of dry AMD and GA. bilateral injections of GS010 has been agreed to with FDA. Based on REVERSE data and post-hoc analyses, we plan on meeting RP Overview with the FDA to ensure that the GS010 clinical development plan RP is the leading cause of hereditary blindness in developed continues to meet their expectations to support a regulatory countries. RP represents a group of related genetic eye disorders submission. The primary endpoint for the REFLECT trial is the that clinical ly manifest in visual disability. The mutations that BCVA reported in LogMAR at 1-Year post-treatment in the second cause RP are heterogeneous and include recessive, dominant and affected/not yet affected eye. The change from baseline in second X-linked forms of more than 100 genes. affected/not yet affected eyes receiving GS010 and placebo RP causes progressive vision loss due to degeneration of rod will be the primary response of interest. The secondary efficacy photoreceptors resulting in the loss of peripheral vision followed endpoints include: BCVA reported in LogMAR at 2-Years post- by degeneration of cone photoreceptors resulting in loss of central treatment in the second affected/not yet affected eye compared vision. The first symptom of RP is usually difficulty with night vision, to both placebo and the first affected eye receiving GS010, OCT, which may occur as early as childhood. The disease progresses over color and contrast sensitivity and quality of life scales. We expect a period of years or decades and often ultimately leads to complete to commence this clinical trial in the first quarter of 2018. If the loss of vision. Some patients become blind as early as age 30, and top-line results of the RESCUE and REVERSE clinical trials are the majority of patients become legally blind before the age of 60. positive, we intend to meet with the FDA throughout 2018 and RP reduces patients’ autonomy and greatly alters the patients’ seek agreement to submit a BLA for approval for the treatment of ability to perform daily life activities. The following images illustrate a LHON, while we continue to conduct our trial. representation of the deterioration of normal vision to blindness in RP. 76 – GENSIGHT BIOLOGICS – 2017 Registration Document