Evaluation of: van den Eertwegh AJ, Versluis J, van den Berg HP et al. Combined
immunotherapy with
granulocyte-macrophage colony-stimulating factor-transduced allogeneic
prostate cancer cells and
ipilimumab in patients with metastatic
castration-resistant
prostate cancer: a Phase 1 dose-escalation trial. Lancet Oncol. 13(5), 509 – 517 (2012). A significant interest in the development of therapeutic
cancer vaccines over the last decade has led to an improvement in overall survival of
cancer patients in several clinical trials. As a result, two active immunotherapy agents,
sipuleucel-T and
ipilimumab, have been approved by the US FDA for the treatment of
prostate cancer and
melanoma, respectively. GVAX(®) cellular
vaccine (Cell Genesysis, Inc., CA, USA) is another active immunotherapy agent targeting
prostate cancer and it has been well studied in various clinical trials. The current publication, by van den Eertwegh et al., demonstrated a combination of two active immunotherapy approaches, using GVAX and
ipilimumab for the treatment of metastatic
castration-resistant
prostate cancer. While GVAX is designed to amplify the antitumor response specific to
prostate cancer cells,
ipilimumab contributes to T-cell activation. Thus, the authors presented the possibility of augmenting antitumor T-cell activity in two different ways. They successfully demonstrated a tolerable dose and safety profile of
ipilimumab in combination with GVAX for patients with metastatic
castration-resistant
prostate cancer. However, further studies of such
immunotherapy combinations and detailed analysis of their immunological effects are needed to observe clinical benefit.