Dual CAR Strategy for Specific and Safe Targeting of T-Cells Against Ovarian
Cancer

Ovarian cancer remains a leading cause of gynecological cancer mortality, with limited effective treatments in its advanced stages. While chimeric antigen receptor T-cell (CAR-T) therapy has transformed hematological cancer care, its success in solid tumors like ovarian cancer remains limited. One major challenge is on-target off-tumor toxicity, where CAR-T cells attack normal tissues expressing the targeted antigen, leading to severe side effects. This toxicity arises from lack of truly tumor-specific antigens and is a significant barrier to applying CAR-T therapy in solid tumors.

To address this, we developed a novel dual CAR-T cell that kills the target cell only when both receptors recognize the target antigens expressed on the tumor. This AND gate activation is achieved by splitting the CAR configuration into two receptors, inducing full stimulation only when both target antigens are recognized. We aimed our dual CAR against CD138 and CD24, which are overexpressed in ovarian cancer, and are expressed to a lower degree in normal cells.

In vitro assays showed that the dual CAR-T cells’ effector functions, including cytokine production and cytotoxicity, were non-inferior to the mono-CAR constructs, while also displaying lower exhaustion levels. In vivo ovarian cancer xenograft models demonstrated a slight reduction in tumor control compared to mono-CARs, yet tumor regression remained significantly superior to that seen with untransduced T-cells. Future validation will focus on the enhanced safety of the dual CAR.

Our approach offers a promising path for safer, more selective CAR-T therapies in ovarian cancer, which may be adapted to other solid tumors.