Clinical Study of PSMA-targeted CAR-T Cells in the Treatment of Castration-resistant Prostate Cancer

We designed a clinical study and divided the trial into two phases. Phase 1 (climbing test): 9 patients were randomly divided into 3 groups (n=3). 9 patients were treated with cyclophosphamide at the dose of 60mg/kg/d 8-7 days before CAR-T cell infusion, and fludalabine at the dose of 25mg/m\^2/d 6-2 days before CAR-T cell infusion. On Day 0, CAR T cells were injected into patients in group 1, 2 and 3 at the dose of 1\*10\^8/ person, 1\*10\^9/ person and 1\*10\^10/ person, respectively. The infusion time exceeded 15-30min. On day 0-14, IL-2 (75000IU/kg) was injected subcutaneously once a day. From day 15-28, IL-2 (75000IU/kg) was subcutaneously injected into the patients three times a week. The purpose of this study is to assess subjects' MTD (maximum tolerated dose) against CAR T cells. Phase 2: After determining the appropriate therapeutic dose for patients with prostate cancer, the remaining 11 patients received the same pre-treatment of chemotherapy. Then, the appropriate therapeutic dose of CAR T cells according to the results of phase 1 was infused on Day 0. On day 0-14,IL-2 (75000IU/kg) was given subcutaneously once a day. On day 15-28, IL-2 (75000IU/kg) was given subcutaneously three times a week. Subjects will collect peripheral blood every four weeks, detect PSA and other related indicators to evaluate the curative effect, safety and survival rate of CAR-T cell transplantation. After 6 months of close follow-up, the subjects will have a quarterly medical history assessment, physical examination and blood test, bone metastasis assessment by bone ECT, prostate and pelvic cavity assessment by prostate MRI, and general information by PET CT if necessary for two years. After this assessment, the subjects will enter an annual telephone follow-up and questionnaire survey for up to five years to assess the long-term health problems of treatment, such as recurrence of malignant tumors.