PARIS, France I May 11, 2021 I Cellectis S.A. (NASDAQ: CLLS – Euronext Growth: ALCLS), a clinical-stage biotechnological company employing its core proprietary technologies to develop best-in-class products based on gene-edited allogeneic CAR T-cells (“UCART”) in the field of immuno-oncology, and Sanofi (Euronext: SAN – NYSE: SNY), today entered into a partnership agreement and a supply agreement regarding alemtuzumab, an anti-CD52 monoclonal antibody, to be used as part of a lymphodepleting regimen in certain Cellectis sponsored UCART clinical trials.

Cellectis is the inventor of the combination of CD52 knockout UCART cells with a lymphodepleting regimen with an anti-CD52 antibody such as alemtuzumab. The CD52 knockout renders its UCART product candidates resistant to alemtuzumab as part of the lymphodepleting regimen. Patients’ lymphodepleting regimens reduce host immune cells and should improve allogeneic CAR T-cell expansion and persistence. In Cellectis sponsored trials, alemtuzumab is currently used as part of the lymphodepleting regimen for UCART22 in the BALLI-01 clinical trial in relapsed/refractory ALL, and for UCART123 in the AMELI-01 clinical trial in relapsed/refractory AML, but not for UCARTCS1 which has a self-lymphodepleting activity. Both Cellectis’ UCART22 and UCART123 candidate products have the CD52 gene inactivated by TALEN® gene editing technology.

As part of the agreement, Sanofi will supply alemtuzumab to support Cellectis’ clinical trials and the parties agreed to enter into discussions to execute a commercial supply of alemtuzumab under pre-agreed financial conditions.

About Cellectis

Cellectis is developing the first of its kind 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. As a clinical-stage biopharmaceutical company with over 21 years of 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 target and eradicate cancer cells.

As part of its commitment to a cure, Cellectis remains dedicated to its goal of providing life-saving UCART product candidates to address unmet needs for multiple cancers including acute myeloid leukemia (AML), B-cell acute lymphoblastic leukemia (B-ALL) and multiple myeloma (MM). 

Cellectis headquarters are in Paris, France, with additional 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). For more information, visit

SOURCE: Cellectis