Washington, DC (UroToday.com) In today’s prostate cancer session at the 2015 Society of Urologic Oncology, Dr. Charles Drake from Johns Hopkins University reviewed the state of immunotherapy for prostate cancer. To date, no objective responses were observed in patients with colorectal or prostate cancer. A phase 3 study of ipilimumab in post docetaxel mCRPC failed to show any advantage to CTLA4 inhibitors. Another trial failed also in the pre docetaxel no visceral metastases setting also.
Dr Drake hypothesized that single agent check point inhibitors are doomed to fail and the answer is probably in combination therapy. Dr Drake then presented 3 trials in which combination therapy is attempted. First, a combination of PD1 inhibitor and CTLA4 inhibitor will be given to CRPC patients. “The tumor is infiltrated by both CD4 and CD8 cells so there is logic in this combination” says Dr Drake. Second the combination of cryoablation and PD1 inhibitors may be beneficial as cryoablation is known to create an inflammatory response in the tissue and the PD1 drug will direct that inflammation against the tumor. Finally, with the same reasoning GVAX vaccine will be given in combination with PD1 inhibitors in the neoadjuvant setting and the level of CD8 infiltration in the prostate will be measured.
Dr. Charles Drake
Johns Hopkins University
Dr. Miki Haifler, MD. from the Society of Urologic Oncology Meeting - December 2 - 4, 2015 – Washington, DC.
Fox Chase Cancer Center, Philadelphia, PA.