Current Clinical Trials in Immunotherapy for Prostate Cancer.
The Prostate Cancer Research Institute (PCRI) has listed four (4) Phase 2 or Phase 3 clinical trials which are currently recruiting patients. These trials all involve immunotherapeutic agents. The first is a Phase 3 trial of ProstAtak® coupled with standard radiation therapy for localized prostate cancer. Patients should be newly diagnosed with intermediate to high risk disease, having received less than 6 months of hormonal therapy, and with no metastases or no local treatment. The trial is recruiting in several states and at institutions such as Johns Hopkins and Walter Reed in Maryland and Memorial Sloan Kettering in New York. Second, a Phase 2 study involving Ipilimumab (Yervoy®) with abiraterone acetate (Zytiga®) plus prednisone in chemotherapy and immunotherapy-naïve patients with progressive metastatic hormone-resistant prostate cancer is recruiting patients at Memorial Sloan Kettering in New York. Ipilimumab is a human monoclonal antibody currently approved for the treatment of melanoma. Third, another Phase 2 study involving Provenge® (Sipuleucel-T) coupled with immediate or delayed CTLA-4 blockade is recruiting in San Francisco. CTLA-4 (cytotoxic T-lymphocyte-associated protein 4) is a protein receptor found on the surface of T-cells that down-regulates the immune system. The CTLA-4 receptor acts as an “off” switch for the attack of cancer cells by T-cells. Hence blocking the CTLA-4 receptor would enhance T-cell anticancer activity. Finally, a Phase 3 trial (Prospect) involving Prostvac in men with few or no symptoms of metastatic, hormone-resistant prostate cancer is recruiting patients. This Prospect trial has been described in a previous blog posted on August 5th, 2014.