Clinical Proof-of-Concept of a Non-Gene Editing Technology Using miRNA-Based shRNA to Engineer Allogeneic CAR...

Area of Science:

• Immunotherapy
• Oncology
• Cellular Therapy

Background:

• Chimeric antigen receptor (CAR) T-cell therapy shows success in B-cell cancers, but autologous manufacturing is complex.
• Allogeneic CAR T-cells offer a potential solution but require mitigation of graft-versus-host disease (GvHD).
• Existing methods for allogeneic CAR T-cells often involve gene editing, which can be time-consuming and complex.

Purpose of the Study:

• To develop a non-gene-edited allogeneic CAR T-cell therapy to prevent GvHD.
• To evaluate the efficacy and safety of allogeneic anti-B-cell maturation antigen CAR T-cells (CYAD-211) in a Phase-I clinical trial.
• To demonstrate the potential of microRNA (miRNA)-based short hairpin RNA (shRNA) technology in controlling T-cell receptor (TCR) activity.

Main Methods:

• Engineered allogeneic anti-B-cell maturation antigen CAR T-cells (CYAD-211) to co-express an anti-CD3ζ miRNA-based shRNA.
• Downregulated T-cell receptor (TCR) expression below detectable levels using the shRNA.
• Evaluated CYAD-211 in vitro for TCR-mediated signaling inhibition and in vivo for GvHD prevention in a mouse model.
• Conducted a Phase-I clinical trial (NCT04613557) in patients with relapsed or refractory multiple myeloma.

Main Results:

• CYAD-211 efficiently inhibited TCR-mediated signaling in vitro.
• CYAD-211 demonstrated effective GvHD prevention in vivo.
• The Phase-I trial showed no signs of GvHD in multiple myeloma patients despite CAR T-cell engraftment.
• Successful downregulation of TCR expression was confirmed in patients.

Conclusions:

• Non-gene-edited technology can generate fully functional allogeneic CAR T-cells without GvHD.
• CYAD-211 represents a promising approach for allogeneic CAR T-cell therapy in multiple myeloma.
• Further research is needed to enhance CAR T-cell persistence and long-term activity for improved clinical outcomes.