Therapeutic anti-cancer vaccines developed to treat metastatic disease such as advanced prostate cancer or melanoma rarely have a noticeable effect on the tumour but have been associated with a statistically significant increase in patient survival.

Robert O. Dillman, MD, NeoStem, Inc., asserts that "overall survival" rather than "progression-free survival" should be the gold standard for evaluating the efficacy of cancer vaccines in clinical trials, in a provocative new article published in Cancer Biotherapy and Radiopharmaceuticals, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers.

The article is available free on the Cancer Biotherapy and Radiopharmaceuticals website until May 6, 2015.

In the article "Cancer Vaccines: Can They Improve Survival?" Dr. Dillman differentiates between the two key endpoints typically used to assess therapeutic cancer vaccines in clinical studies.

As cancer vaccines are designed to stimulate an immune response to cancer cells and induce long-term memory recognition of a tumour, they may improve overall survival even if they do not appear to slow the progression of disease.

Although measuring overall survival compared to progression-free survival would usually require longer clinical trials, overall survival may be the only relevant efficacy endpoint, the author concludes.

"This is a timely article considering the number of vaccine and antibody immunotherapy trials ongoing or planned," says Co-Editor-in-Chief Donald J. Buchsbaum, PhD, Department of Radiation Oncology, Division of Radiation Biology, University of Alabama at Birmingham. "The conclusion that overall survival is the best clinical endpoint for efficacy in therapeutic vaccine and antibody immunotherapy trials in patients with metastatic cancer is based on an analysis of four completed trials."

Source - AlphaGalileo