Relationship of therapeutic cancer vaccine development to population disease burden and five-year survival

In the US, therapeutic vaccines may provide considerable benefit to cancer patients. Yet, there has been no assessment of whether vaccines currently in the research and development pipeline reflect the burden of disease and current survival patterns for different malignancies. The authors used data from the National Cancer Institute, Surveillance Epidemiology and End Results (SEER) database, and clinicaltrials.gov registry to characterize the vaccine development pipeline with respect to five measures of disease burden and treatment effectiveness for cancer: annual incidence, annual mortality, 5-y survival rate, recent change in 5-y survival (1999-2006 vs 1990-1992), and 5-y mortality estimate [= annual incidence*(1 - 5-y survival rate)]. In 2011, the authors identified 231 active clinical trials for therapeutic cancer vaccines. Of these trials, 81 vaccines are currently in Phase I, 140 in Phase II, and 10 vaccines in Phase III. Vaccine trials for melanoma are most common (n = 40), followed by breast cancer (34), lung cancer (30), and prostate cancer (22). Correlation analyses revealed that only annual cancer incidence is significantly associated with current therapeutic cancer vaccine trial activity (r = 0.60; p = 0.003). Annual mortality, 5-y survival rate and 5-y mortality estimates are not associated with vaccine trial activity. The authors conclude that therapeutic cancer vaccine clinical trials correspond with disease incidence in the US, but not with measures of mortality and survival that reflect the effectiveness of currently available treatment modalities. Future development of therapeutic vaccines for cancer may benefit patients more if there is stronger complementarity with other therapeutic options.