GenSight Biologics Reports Cash Position as of June 30, 2026, and Provides Business Updates

Regulatory News:

GenSight Biologics (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 reported its cash position as of June 30, 2026, and provided business updates.

Cash Position as of June 30, 2026

GenSight Biologics’ cash and cash equivalents totaled €1.7 million as of June 30, 2026, compared to €3.2 million as of March 31, 2026.

The operating cash burn in the second quarter of 2026 mainly reflects the management of GS010/LUMEVOQ^®, Early Access Programs, primarily in France and Israel, as well as the preparation of the Phase III RECOVER study for GS010, GenSight’s gene therapy for Leber Hereditary Optic Neuropathy (LHON).¹

Proceeds from Early Access Programs

During the first half of 2026, the Company collected €6.8 million in cash proceeds from its early access Programs, of which €4.3 million was collected during the second quarter of 2026. These proceeds were received between the end of March and mid-June 2026 and include payment for the first patient treated under the Company’s Paid Named Patient Program in Israel.

Following the July 2021 reform in France (Decree No. 2021-869 of June 30, 2021 on early access authorizations), companies are required to issue a rebate based on the total compensation received for early access treatments performed in France over a calendar year. The payment, which is determined based on a progressive scale, is due in November of the following year. Accordingly, the Company will pay a rebate based on proceeds received from the 2026 French Named Patient Early Access Program (AAC) in November 2027, which is expected to range from 25% to 35%.

More treatments are expected to be carried out this year under early access programs in various countries.

Business Updates

The AAC program may also be accessible to citizens of other European Union countries, not only to residents of France. In the first half of 2026, the Company treated the first patients from other European countries under the program.

During the spring of 2026, the Company continued to improve and optimize the existing manufacturing process for GS010/LUMEVOQ^® at Catalent, its contract manufacturing organization. The engineering run was initiated in June. The final confirmatory tests are currently underway, and the Company expects to confirm the success of the technology transfer in the summer of 2026. Following this confirmation, GenSight will begin manufacturing the batches required to supply both the Phase III RECOVER study and its Early Access Programs. The Company currently holds more than 60 vials in inventory, which it expects to be sufficient to treat patients through the end of the first half of 2027.

To support these activities, the Company strengthened its organization during this period by adding headcount to reinforce its Quality and CMC (Chemistry, Manufacturing and Controls) departments. The Company also plans to reinforce its clinical team in the second half of 2026.

The Company received request from Heights Capital to defer the June 2026 amortization of the convertible bond to end of December 2027.

Cash Runway

Although the Company is unable to predict the precise timing of treatments and associated payments under its various paid early access programs (in particular those in France and Israel) over the coming year, management currently expects that aggregate revenues from these programs in 2026 should be sufficient to cover the Group’s operating expenses for that period, excluding costs associated with the new Phase III RECOVER clinical trial, which include certain manufacturing costs related to the study.

Financial Agenda

GenSight Biologics will publish its 2026 half-year financial statement on September 29, 2026.

About GenSight Biologics

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.

Forward-Looking Statements

This press release contains forward-looking statements, including statements regarding product development prospects and financial projections. These statements do not constitute guarantees of future performance and involve risks and uncertainties. A further list and description of risks and uncertainties that could cause actual results to differ materially from those set forth in the forward-looking statements in this press release can be found in GenSight Biologics’ regulatory filings with the French Autorité des Marchés Financiers. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements and estimates, which speak only as of the date hereof. Other than as required by applicable law, GenSight Biologics undertakes no obligation to update or revise the information contained in this press release.

Detailed Information

Detailed information regarding the Company, including its business, financial information, results, perspectives and related risk factors are contained (i) in the Company’s 2025 Universal Registration Document filed with the AMF on April 14, 2026, under number D.26-0251 (the "2025 URD"). This document, as well as other regulated information and all of the Company's press releases, can be accessed on the Company's website (www.gensight-biologics.com) and/or AMF (www.amf-france.org). Your attention is drawn to the risk factors related to the Company and its activities presented in chapter 3 of its 2025 URD, in particular the liquidity risk presented in the chapter 3.1.1.

¹ GS010/LUMEVOQ^® has not received marketing authorization in any jurisdiction and is not available commercially.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260708654201/en/

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