Successful eradication of established peritoneal ovarian tumors in SCID-Beige mice following adoptive transfer of T cells genetically targeted to the MUC16 antigen.

PURPOSE Most patients diagnosed with ovarian cancer will ultimately die from their disease. For this reason, novel approaches to the treatment of this malignancy are needed. Adoptive transfer of a patient's own T cells, genetically modified ex vivo through the introduction of a gene encoding a chimeric antigen receptor (CAR) targeted to a tumor-associated antigen, is a novel approach to the treatment of ovarian cancer. EXPERIMENTAL DESIGN We have generated several CARs targeted to the retained extracellular domain of MUC16, termed MUC-CD, an antigen expressed on most ovarian carcinomas. We investigate the in vitro biology of human T cells retrovirally transduced to express these CARs by coculture assays on artificial antigen-presenting cells as well as by cytotoxicity and cytokine release assays using the human MUC-CD(+) ovarian tumor cell lines and primary patient tumor cells. Further, we assess the in vivo antitumor efficacy of MUC-CD-targeted T cells in SCID-Beige mice bearing peritoneal human MUC-CD(+) tumor cell lines. RESULTS CAR-modified, MUC-CD-targeted T cells exhibited efficient MUC-CD-specific cytolytic activity against both human ovarian cell and primary ovarian carcinoma cells in vitro. Furthermore, expanded MUC-CD-targeted T cells infused through either i.p. injection or i.v. infusion into SCID-Beige mice bearing orthotopic human MUC-CD(+) ovarian carcinoma tumors either delayed progression or fully eradicated disease. CONCLUSION These promising preclinical studies justify further investigation of MUC-CD-targeted T cells as a potential therapeutic approach for patients with high-risk MUC16(+) ovarian carcinomas.