FDA Grants Orphan Drug Designation to Cellectis’ CLLS52 (alemtuzumab) For ALL Treatment

New York, NY – August 1, 2024 – 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, today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation (ODD) to Cellectis’ CLLS52 (alemtuzumab), an Investigational Medicinal Product (IMP) used as part of the lymphodepletion regimen associated with UCART22, evaluated in the BALLI-01 clinical trial in relapsed/refractory B-cell acute lymphoblastic leukemia (ALL).

“We are excited that the FDA granted CLLS52 (alemtuzumab) ODD designation status. The importance of adding alemtuzumab to the lymphodepletion regimen has been demonstrated in Cellectis’ BALLI-01 study, where the addition of this lymphodepletion agent to the fludarabine and cyclophosphamide regimen was associated with sustained lymphodepletion and significantly higher UCART22 cell expansion allowing for greater clinical activity”, said Mark Frattini, M.D., Ph.D. Chief Medical Officer at Cellectis.

Cellectis is the inventor of the combination of CD52 knockout UCART cells with a lymphodepleting regimen containing an anti-CD52 antibody such as alemtuzumab. The CD52 knockout aims to render the UCART product candidates resistant to alemtuzumab as part of the lymphodepleting regimen. Cellectis’ UCART22 product candidate has the CD52 gene inactivated by TALEN® gene editing technology.

The FDA grants ODD status to medicines intended for the treatment, diagnosis or prevention of rare diseases or disorders that affect fewer than 200,000 people in the US. Receiving ODD may help to expedite and reduce the cost of development, approval, and commercialization of a therapeutic agent.