GenSight Biologics S.A.

Declaration of Voting Results & Voting Rights Announcements • May 11, 2017

Regulated Information

Annual General Meeting on May 31, 2017 Procedures for obtaining preparatory documents for the General Meeting

Paris, France, May 11, 2017 - 6.00 PM 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, announces that it will hold its Annual General Meeting on May 31, 2017 at 9:00am at the company's headquarters: 74 rue du Faubourg Saint-Antoine, 75012 Paris (France).

The notice containing the agenda and draft resolutions was published in the French BALO on April 26, 2017. The notice confirming the time and place of the meeting will be published in the French BALO and in a legal gazette on May 12, 2017.

The preparatory documents for the General Meeting listed in Article R. 225-73-1 of the French Commercial Code are posted on the company's website (www.gensight-biologics.com) in the Investors, Documentation section.

The preparatory documents for the General Meeting will also be made available to shareholders as of the convening of the meeting. Thus, in accordance with applicable regulatory provisions:

• All registered shareholders may, until five days (included) before the meeting, request by email that the Company sends the documents referred to in Articles L. 225-115 and R. 225-83 of the French Commercial Code. For holders of bearer shares, the exercise of this right is subject to the provision of a certificate of participation in the bearer share accounts held by the authorized intermediary;
• Any shareholder may consult the documents referred to in Articles L. 225-115 and R. 225-83 of the French Commercial Code at the company's headquarters.

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'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.