Immune Science Associates Assessment Analyzes Evolving Strategies

(Amherst, NH) – Efforts to up-regulate the human immune system to recognize and destroy tumor cells with minimal side effects and collateral damage to healthy tissue continue to attract a mixture of optimism and determination from vaccine developers and skepticism from potential Pharma partners. Despite a number of setbacks and sector participant attrition due to funding issues or sector consolidation, about three dozen companies are actively pursuing therapeutic cancer vaccines (TCVs), with vaccine candidates in various stages of clinical trial.

Over the past thirty-six months, there has been a shift in the source of antigens for TCVs, with a steep drop in the number of TCVs based on allogeneic tumor cells or immortalized cell lines. About half of the companies with TCVs currently in clinical trials have opted to use engineered antigens, which they administer via transfected DNA in a host vector or deliver either as fusion proteins or encapsulated in synthetic particles. About a dozen are employing autologous tumor extracts as a source of epitopes. While partnerships such as the license agreement between Oxford Biomedica and Sanofi-Aventis for TroVax will help, most TCV companies will continue to struggle financially as they endure extended time lines and challenging trial end points.

Clinical trial endpoints for cancer vaccines include criteria on tumor shrinkage, delayed time to progression, immunologic end points, and molecular markers – endpoints that cannot be measured with true analytical accuracy or precision among patients. This error factor is compounded by the often small trial populations that result from the narrow focus of many cancer vaccine disease targets. Up to this point, evidence of immunologic response and clinical responses in small patient populations, correlation between immunologic response and clinical response has been difficult to demonstrate.

These findings are contained in a new and comprehensive report: Therapeutic Cancer Vaccines: Evolving Strategies & Pipeline Prospects. Researched and written by Immune Science Associates, a premier immunology consultancy, the report is available from Greystone Associates.

Source: Greystone Associates