Cellectis to Report Second Quarter 2023 Financial Results on August 3, 2023

NEW YORK, July 27, 2023 (GLOBE NEWSWIRE) — Cellectis S.A. (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, today announced that it will report financial results for the second quarter ended June 30, 2023 on Thursday, August 3, 2023 after the close of the US market. The announcement will be followed by an investor conference call and webcast on Friday, August 4, 2023 at 8:00 am ET / 2:00 pm CET. The call will include the Company’s second quarter results and an update on business activities. Details for the call are as follows: Dial in information: Domestic: 1-877-451-6152 International: 1-201-389-0879 Conference ID: 13739252 Webcast Link: https://viavid.webcasts.com/starthere.jsp?ei=1619596&tp_key=40e9fac8fc About Cellectis Cellectis is a clinical-stage biotechnology company using its pioneering gene-editing platform to develop life-saving cell and gene therapies. Cellectis utilizes an allogeneic approach for CAR-T immunotherapies in oncology, pioneering the concept of off-the-shelf and ready-to-use gene-edited CAR T-cells to treat cancer patients, and a platform to make therapeutic gene editing in hemopoietic stem cells for various diseases. As a clinical-stage biopharmaceutical company with over 23 years of experience and expertise in gene editing, Cellectis is developing life-changing product candidates utilizing TALEN®, its gene editing technology, and PulseAgile, its pioneering electroporation system to harness the power of the immune system in order to treat diseases with unmet medical needs. Cellectis’ headquarters are in Paris, France, with locations in New York, New York and Raleigh, North Carolina. Cellectis is listed on the Nasdaq Global Market (ticker: CLLS) and on Euronext Growth (ticker: ALCLS). Forward-looking Statements This press release contains “forward-looking” statements within the meaning of applicable securities laws, including the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by words such as “anticipate,” “expect,” “plan,” “could” and “will,” or the negative of these and similar expressions. These forward-looking statements, which are based on our management’s current expectations and assumptions and on information currently available to management. These forward-looking statements are made in light of information currently available to us and are subject to numerous risks and uncertainties, including with respect to the numerous risks associated with biopharmaceutical product candidate development. With respect to our cash runway, our operating plans, including product development plans, may change as a result of various factors, including factors currently unknown to us. Furthermore, many other important factors, including those described in our Annual Report on Form 20-F and the financial report (including the management report) for the year ended December 31, 2022 and subsequent filings Cellectis makes with the Securities Exchange Commission from time to time, as well as other known and unknown risks and uncertainties may adversely affect such forward-looking statements and cause our actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons why actual results could differ materially from those anticipated in the forward-looking statements, even if new information becomes available in the future. For further information on Cellectis, please contact: Media contact: Pascalyne Wilson, Director, Communications, +33 (0)7 76 99 14 33, [email protected] Investor Relations contacts: Arthur Stril, Chief Business Officer, +1 (347) 809 5980, [email protected] Ashley R. Robinson, LifeSci Advisors, +1 617 430 7577 Attachment Q2 2023 earnings call announcement