Cellectis Showcased Preclinical Data at an Oral Presentation and Two Poster Presentations at the 29th International Society for Cell & Gene Therapy (ISCT 2023) Annual Event - Seite 2

UCART20x22 is Cellectis’ first dual-targeting, allogeneic cell therapy product candidate targeting CD20 and CD22, to address the current challenges in the treatment of B-cell malignancies.

UCART20x22 features TALEN-mediated disruptions of the TRAC gene (to minimize the risk of graft-versus-host disease) and of the CD52 gene (to permit use of a CD52-directed monoclonal antibody in patients’ lymphodepletion regimen) to enhance CAR T engraftment, expansion, and persistence.

Cellectis demonstrates that UCART20x22 displays robust activity in vitro and in vivo, against targets expressing heterogeneous levels of CD22 and CD20. We have used in vitro cytotoxicity assays against different tumor cell lines, showing strong activity whether these cells express a single antigen (CD20 or CD22) or both antigens simultaneously, as well as IFNg release in response to antigen specific stimulation.

The oral presentation highlighted the following preclinical data:

• Robust in vitro and in vivo cytolytic activity against tumors expressing different antigen combinations.
  

• Efficient in vitro targeting of primary B-cell Non-Hodgkin Lymphoma (B-NHL) samples harboring different CD20 and CD22 expression levels, suggesting that UCART20x22 has the potential to reach a large patient population.
  

• Dose dependent tumor control in vivo, using batches manufactured internally, harboring a tumor cell line as well as in a Patient Derived Xenograft (PDX) model of B-NHL.
  

Overall, Cellectis provided pre-clinical proof-of-concept data for a first allogeneic dual CAR T-cell to overcome current mechanisms of resistance to CAR T-cell therapies in B-NHL, while providing a potential therapeutic alternative to CD19 targeting and allowing to reduce the time from treatment decision to infusion.

UCART20x22 is currently evaluated in the NATHALI-01 Phase 1/2a clinical study in patients with relapsed/refractory B-NHL (NCT05607420).

The oral presentation is available on Cellectis’ website: https://www.cellectis.com/en/investors/scientific-presentations/

Poster Presentations:

Non-viral DNA delivery associated to TALEN gene editing leads to highly efficient correction of sickle cell mutation in long-term repopulating hematopoietic stem cells

Sickle cell disease stems from a single point mutation in the HBB gene which results in sickle hemoglobin. For patients who are not eligible for an allogeneic stem cell transplantation, nuclease-based gene therapy approaches provide a relevant therapeutic alternative to restore functional hemoglobin production.