Paris, France, September  19, 2017, 7.30am CET – GenSight Biologics (Euronext: SIGHT, ISIN: FR0013183985, PEA-PME eligible), a biopharma company that discovers and develops innovative gene therapies for neurodegenerative retinal diseases and diseases of the central nervous system, announced its stock has been included, as of September 18, 2017, in the CAC® Small, CAC® Mid and Small and CAC® All-Tradable indexes following their annual review by the Euronext Scientific Board on Indices.

Thomas Gidoin, Chief Financial Officer of GenSight Biologics, commented, “In just over a year after our first steps on Euronext Paris as a public company, inclusion in the CAC family of indexes is improving the visibility of the stock, and potentially its liquidity.”

About GenSight Biologics

GenSight Biologics S.A. is a clinical-stage biotechnology company discovering and developing novel therapies for neurodegenerative retinal diseases and diseases of the central nervous system. GenSight Biologics’ pipeline leverages two core technology platforms, the Mitochondrial Targeting Sequence (MTS) and optogenetics for retinitis pigmentosa, to help preserve or restore vision in patients suffering from severe degenerative retinal diseases. GenSight Biologics’ lead product candidate, GS010, is in Phase III trials in Leber’s Hereditary Optic Neuropathy (LHON), a rare mitochondrial disease that leads to irreversible low vision and legal blindness in teens and young adults. Using its gene therapy-based approach, GenSight Biologics’ product candidates are designed to be administered in a single treatment to each eye by intravitreal injection to offer patients a sustainable functional visual

recovery.

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