Dr. Mathieu Simon to Retire as Cellectis’ Chief Operating Officer; Elsy Boglioli Named as Successor

March 13, 2018 – New York (N.Y.) – Cellectis (Euronext Growth: ALCLS - Nasdaq: CLLS), a clinical-stage biopharmaceutical company focused on developing immunotherapies based on gene-edited allogeneic CAR T-cells (UCART), announced today that Dr. Mathieu Simon is retiring as Executive Vice President and Chief Operating Officer, effective immediately. Following a smooth and successful transition over the last few months, Elsy Boglioli, Executive Vice President, Strategy and Corporate Development, is named Chief Operating Officer.

“Dr. Simon has been incredibly instrumental in the strategic and operational direction of the therapeutic activities at Cellectis. Among his many achievements during his tenure, Dr. Simon helped to fundamentally transform Cellectis from a research-oriented biotech company to a clinical-stage biopharma player. I warmly thank him for his service,” said Dr. Choulika, Cellectis Chief Executive Officer. “I look forward to Elsy Boglioli’s leadership as our new Chief Operating Officer as we enter the next phase of the Company’s development.”

Dr. Mathieu Simon has served as Cellectis’ Executive Vice President since 2012 and as Chief Operating Officer since 2013. He was a member of Cellectis’ board of directors as well.

“I am truly proud of our achievements at Cellectis over the last six years, including building a solid product candidate portfolio, advancing two allogeneic product candidates developed by Cellectis into the clinic and working strategically alongside our collaboration partners. It has been a great privilege to serve Cellectis and I am now ready to retire with enthusiasm for the Company’s future, confidence in the work that the Cellectis management team will continue, and gratitude for the many colleagues I have had the great pleasure to work with,” said Dr. Mathieu Simon. “I am delighted with Elsy Boglioli’s appointment as COO. Elsy brings a wealth of biopharmaceutical industry experience, having worked with leading pharmaceutical companies. Her unique blend of capabilities, relationships, and expertise will be invaluable assets to Cellectis.”