Cellectis Announces First Patient Treated in Phase 1 Trial of UCART19 in Pediatric Acute B Lymphoblastic Leukemia (B-ALL)

New York, N.Y. – June 20, 2016 – Cellectis (Alternext: ALCLS – Nasdaq: CLLS), a biopharmaceutical company focused on developing immunotherapies based on gene edited CAR T-cells (UCART), today announced that the first patient has been treated in the Phase I study of UCART19 in pediatric acute B lymphoblastic leukemia (B-ALL) at the University College of London (UCL). This UCART19 clinical trial is sponsored by Servier in close collaboration with Pfizer.

The pediatric Phase I is an open label, non-comparative, monocenter study to evaluate the safety and ability of UCART19 to induce molecular remission in pediatric patients with relapsed or refractory CD19 positive B-cell acute lymphoblastic leukemia ahead of planned allogeneic haematopoeitic stem cell transplantation (allo-HSCT).

Cellectis will receive a milestone payment from Servier of an undisclosed amount.

About UCART19

UCART19 is an allogeneic CAR T-cell product candidate developed for treatment of CD19-expressing hematological malignancies, gene edited with TALEN®. UCART19 is initially being developed in chronic lymphocytic leukemia (CLL) and acute lymphoblastic leukemia (ALL). Cellectis’ approach with UCART19 is based on the preliminary positive results from clinical trials using autologous products based on the CAR technology, and has the potential to overcome the limitation of the current autologous approach by providing an allogeneic, frozen, “off-the-shelf” T cell based medicinal product.

In November 2015, Servier acquired the exclusive rights to UCART19 from Cellectis. Following further agreements, Servier and Pfizer began collaborating on a joint clinical development program for this cancer immunotherapy. Pfizer has exclusive rights from Servier to develop and commercialize UCART19 in the United States, while Servier retains exclusive rights for all other countries.