GenSight Biologics S.A.

Report Publication Announcement • Oct 26, 2017

Press release

GenSight Biologics Reports its Cash Position as of September 30, 2017

Paris, France, October 26, 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, today reported its cash position as of September 30, 2017.

Cash and cash equivalents

GenSight Biologics' cash and cash equivalents amounted to €59.5 million as of September 30, 2017, compared to €63.6 million as of June 30, 2017.

Number of outstanding shares

As of September 30, 2017, GenSight Biologics' number of outstanding shares was 24,234,223 ordinary shares.

GenSight Biologics will report its cash position as of December 31, 2017 on January 25, 2018.

Contacts

GenSight Biologics Thomas Gidoin Chief Financial Officer tgidoin@gensight-biologics.com +33 (0)1 76 21 72 20

RooneyPartners

Media Relations Marion Janic mjanic@rooneyco.com +1-212-223-4017

The Trout Group

Investor Relations Chad Rubin crubin@troutgroup.com +1-646-378-2947

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 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.