Provenge (Sipuleucel T), the prostate cancer “vaccine” from Dendreon Corporation, was approved by the FDA Thursday. The immunotherapy agent has been found in clinical trials to increase overall survival by several months compared to placebo:
“In the largest clinical trial of Provenge, involving 512 men, those who got Provenge had a median survival of 25.8 months after treatment, while those who got a placebo lived a median of 21.7 months. After three years, 32 percent of those who got Provenge were alive, compared with 23 percent of those who got the placebo. The main side effects were fever, chills, fatigue and pain.”
The agent is a cell-based vaccine created by exposing autologous antigen-presenting peripheral blood mononuclear cells (enriched for a dendritic cell fraction) to a recombinant protein consisting of granulocyte-macrophage colony-stimulating factor (GM-CSF) fused to prostatic-acid phosphatase (PAP). When the now specifically immunocompetent cells are reintroduced to the patient, the hope is that an antitumor T-cell response will be generated against tumor cells expressing PAP. (NCI)
While this is by no means a cure to the most common non-skin cancer in men, it’s a step in the right direction. Immunotherapy is all the rage these days, and, hopefully, success stories like this will help foster further breakthroughs in the field.