Study of Fully Human B7H3 CAR-T in Treating Recurrent Malignant Ovarian Cancer

The purpose of this study is to test the safety and efficacy of a newly developed fully human scFv-armed B7H3 targeting chimeric antigen receptor T cells (fhB7H3.CAR-Ts), which are supposed to attack and eliminate B7H3-positive cancer cells. The patients who have been diagnosed as recurrent or relapsed malignant ovarian cancer, especially ovarian cancer patients with refractory ascites, will be potentially enrolled after assessing the expression of B7H3 antigen in tumor tissue by immunohistochemistry staining or ascitic tumor cells by flow cytometry. After enrollment, participants' peripheral blood mononuclear cells will be collected and used to manufacture fhB7H3.CAR-Ts. Before infusion, the patients will receive lymphodepletion chemotherapy with cyclophosphamide and fludarabine for three consecutive days. Two days later after lymphodepletion, the fhB7H3.CAR-Ts would be given through an abdominal catheter for intraperitoneal infusion. From the day of infusion, participants' peripheral blood and ascites will be collected twice a week in the first month for monitoring the survival of fhB7H3.CAR-Ts and evaluating the therapeutic efficacy. Additional follow-up and examination will be performed monthly for the first three month and then trimonthly until one year. Thereafter, annual follow-up will be completed for 5 years. In addition, since the fhB7H3.CAR-Ts containing a RQR8 safety-switch which could be targeted and removed by Rituximab. Participants who experience life-threatening toxicities caused by uncontrollable proliferation of fhB7H3.CAR-Ts will receive infusion of Rituximab (Rituxan or Ruxience or Halpryza) to assess the ability of RQR8 safety-switch to eliminate infused fhB7H3.CAR-Ts. This is an investigator-initiated clinical study to assess first-line clinical performance of novel fhB7H3.CAR-Ts which may help other advanced and recurrent ovarian cancer patients in the future.