Cellectis Announces Arbitral Decision in Dispute with Servier

New York (NY) - December 16, 2025 - Cellectis (the "Company") (Euronext Growth: ALCLS - NASDAQ: CLLS), a clinical-stage biotechnology company using its pioneering gene-editing platform to develop life-saving cell and gene therapies, announces that the Arbitral Tribunal has issued its decision in the arbitration proceedings against Les Laboratoires Servier and Institut de Recherches Internationales Servier IRIS SARL ("Servier"), relating to the License, Development and Commercialization Agreement entered into between Servier and Cellectis on March 6, 2019, as amended (the "License Agreement").

The Tribunal ruled on a partial termination of the License Agreement with respect to product UCART19 V1 (also referred to as "ALLO-501" by Allogene) and provided that Cellectis shall, at Allogene's request, engage in good-faith discussions regarding the granting of a direct license to product UCART19 V1. All other claims brought by the parties were dismissed.