NOT FOR DISTRIBUTION, DIRECTLY OR INDIRECTLY, IN THE UNITED STATES OF AMERICA, CANADA, AUSTRALIA, JAPAN AND SOUTH AFRICA

PRESS RELEASE

GenSight Biologics Announces the Closing of its Nearly €1.7 Million Fundraising

Paris, France, March 17, 2026, 6:00 pm CET – GenSight Biologics (the "Company") (Euronext: SIGHT, ISIN: FR0013183985, PEA-PME eligible), a biopharma company focused on developing and commercializing innovative gene therapies for retinal neurodegenerative diseases and central nervous system disorders, today announced the closing of its EUR 1,694,715.5256 fundraising (the "Fundraising").

The Fundraising resulted in the issuance of:

• (i) 14,153,928 ordinary shares (actions ordinaires) of the Company (the "Offered Shares"), which were admitted to trading on Euronext Paris on March 12, 2026 (ISIN FR0013183985/SIGHT);
• (ii) 4,270,464 pre-funded warrants (the "Offered Pre-Funded Warrants") giving the right to subscribe to 4,270,464 additional ordinary shares; and
• (iii) 18,424,392 warrants (the "Offered Investor Warrants") giving the right to subscribe to 9,212,196 additional ordinary shares.

The Offered Investor Warrants and the Offered Pre-Funded Warrants will not be admitted to trading on any venue.

Risk factors

The Company draws the attention of the public to the risk factors relating to the Company and its business described in its 2024 Universal Registration Document, as completed by the Information Document published by the Company on March 10, 2026, both of which are available free of charge on the Company's website (https://www.gensight-biologics.com/), with the Information Document being directly available through the following hyperlink: https://www.gensight-biologics.com/wp-content/uploads/2026/03/GenSight-2026-1-Annexe-IX-FINALvdef.pdf.

Contacts

GenSight Biologics
Chief Financial Officer
Jan Eryk Umiastowski
jeumiastowski@gensight-biologics.com

About GenSight Biologics S.A.

GenSight Biologics S.A. is a clinical-stage biopharma company focused on developing and commercializing 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 (lenadogene nolparvovec) is in Phase III in Leber Hereditary Optic Neuropathy (LHON), a rare mitochondrial disease that leads to irreversible blindness in teens and young adults. GS010 is currently in clinical development, has not to date been granted marketing authorization in France or any other jurisdiction, and is therefore not available commercially. 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.

Disclaimer

Not for release, directly or indirectly, in or into the United States of America, Canada, Australia, Japan or South Africa. This press release and the information contained herein do not contain or constitute an offer to subscribe or purchase, or the solicitation of an order to purchase or subscribe, for securities in the United States of America or in any other jurisdiction where such an offer or solicitation would be unlawful. The securities referred to herein have not been and will not be registered under the Securities Act, or under the securities laws of any state or other jurisdiction of the United States of America, and may not be offered or sold in the United States of America except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and in compliance with the securities laws of any state or any other jurisdiction of the United States. GenSight Biologics does not intend to make a public offering of the securities in the United States of America.

The distribution of this press release may be subject to legal or regulatory restrictions in certain countries. Persons in possession of this press release should inform themselves of and observe any local restrictions. The information contained herein is subject to change without notice.

Forward-Looking Statements

This press release contains forward-looking statements. All statements, other than statements of historical facts, included in this press release are forward-looking statements. These forward-looking statements include, but are not limited to, statements regarding the completion expected proceeds and anticipated use of proceeds of the Fundraising; the anticipated cash runway of the Company; and future expectations, plans and prospects of the Company. Words such as "anticipates", "believes", "expects", "intends", "projects", and "future" or similar expressions are intended to identify forward-looking statements. These forward-looking statements are subject to the inherent uncertainties in predicting future results and conditions and no assurance can be given that the proposed securities offering discussed above will be consummated on the terms described or at all. Completion of the proposed Fundraising and the terms thereof are subject to numerous factors, many of which are beyond the control of the Company, including, without limitation, market conditions, failure of customary closing conditions and the risk factors and other matters set forth in the filings the Company makes with the AMF from time to time. The Company expressly disclaims any obligation to update any forward-looking statements, whether because of new information, future events or otherwise, except as may be required by law.