A Phase 1 Study to Evaluate Chimeric Antigen Receptor (CAR) T cells Targeting TAG72 in Patients with Recurrent Epithelial Ovarian Cancer

PROJECT SUMMARY Patients with recurrent epithelial ovarian cancer (EOC) have a poor prognosis with a post-relapse median survival of approximately 30 months and limited therapeutic options, thus presenting a fundamental unmet medical need. Progress in immunotherapy across a broad range of tumor types provides hope that immunological approaches may improve outcomes for patients with EOC. Particularly, a type of immunotherapy called chimeric antigen receptor (CAR) T cell therapy retrains the immune system to target cancers by recognizing specific cancer markers. EOC presents several challenges to effective CAR T cell immunotherapy, including poor tumor site infiltration, activation, inadequate function and persistence of these T cells within the harsh peritoneal tumor microenvironment. Additionally, there are a lack of effective CAR T cell targets on the surface of advanced EOC tumor cells. Our goal is to develop effective therapies against metastatic EOC, with a specific focus on regional delivery of CAR T cell therapies to treat peritoneal metastasis. TAG72 is highly over- expressed in EOC and other solid tumors with little or no expression in normal tissues, making it an ideal target for CAR T cell therapy. Our team at City of Hope has developed and completed laboratory testing of a TAG72- targeting CAR T cell therapy. Our preclinical data also supports superior anti-tumor activity when TAG72 CAR T cells are administered regionally by intraperitoneal delivery versus systemically by intravenous delivery, likely due to direct and immediate antigen CAR T cell access to tumor cells. The hypothesis is that regionally- administered TAG72-CAR T cells will be safe and mediate anti-tumor effects, which will be assessed in the following specific aims: 1) Evaluate safety and feasibility of regional intraperitoneal delivery of TAG72-CAR T cells in patients with advanced EOC in a phase 1 clinical trial; 2) Assess CAR T cell-mediated immune landscape changes that may indicate therapeutic response or resistance; and 3) investigate pathways of tumor resistance and CAR T cell-induced tumor evolution. Our program has incorporated an innovative use of pre-conditioning regimens to our solid tumor CAR T cell therapies, regional routes of CAR T cell administration, and a fully- optimized TAG72-CAR construct. These features aim to improve the potency and selectivity of targeting TAG72+ tumors while potentially minimizing immune responses that limit persistence and/or function of TAG72-CAR T cells. This approach is significant in that it will expand our therapeutic portfolio for EOC and other solid tumors.