GenSight Biologics S.A.

Report Publication Announcement • Apr 27, 2018

Press Release

GenSight Biologics Announces the Filing of its 2017 Registration Document

Paris, France, April 27, 2018, 8.00 pm CET – GenSight Biologics (Euronext: SIGHT, ISIN: FR0013183985, PEA-PME eligible), a biopharma company focused on discovering and developing innovative gene therapies for retinal neurodegenerative diseases and central nervous system disorders, today announced the filing of its 2017 Registration Document in English, registered by the French market authority (Autorité des Marchés Financiers, or AMF) on April 27, 2018 under number R-18-036.

The 2017 Registration Document includes, among other things, the following:

• the 2017 financial report;
• the management report;
• the report on corporate governance ; and
• the description of the share buyback program.

This registration document may be consulted on the Company's website: www.gensight-biologics.com, under "Investors", and on the AMF's website: www.amf-france.org. Printed copies of the 2017 Registration Document are also available to the public free of charge upon request at the Company's headquarters located 74 rue du Faubourg Saint-Antoine, 75012 Paris, France.

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

James Palmer

Europe Investor Relations j.palmer@orpheonfinance.com +33 7 60 92 77 74

About GenSight Biologics

GenSight Biologics S.A. is a clinical-stage biopharma company focused on discovering and developing innovative gene therapies for retinal neurodegenerative diseases and central nervous system disorders. GenSight Biologics' pipeline leverages two core technology platforms, the Mitochondrial Targeting Sequence (MTS) and optogenetics to help preserve or restore vision in patients suffering from blinding 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 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.