Cancer Vaccines
There is a great expectation that cancer vaccines will offer advantages over conventional cancer treatments such as chemotherapy and radiotherapy. Vaccines are likely to produce fewer and milder side-effects as they specifically target cancer cells only.
An ideal cancer vaccine would induce a strong and sustained immune response against a cancer antigen that is expressed only on cancer cells. Thus identifying an antigen is the first step in developing an effective cancer vaccine. The Cancer Antigen Discovery Collaborative (CADC), another joint CRI and LICR effort, convenes an international group of scientists to identify and characterize cancer antigens to which cancer vaccines can be targeted. A number of promising cancer antigens, including NY-ESO-1, MAGE-3, NY-BR-1, SSX-2, NY-CO-58, and MELAN-A, are often found in certain cancer types, including melanoma, and breast, prostate, lung, colon, ovarian, and bladder carcinomas, and were discovered by LICR investigators and by members of the CADC. The CADC continues to identify and feed potential cancer antigens into the CVC pipeline of clinical discovery (see diagram of CADC/CVC Process).
The ideal immune response to a cancer vaccine would be ‘integrated,’ meaning that all components of the immune system, CD8+ T cells, CD4+ T cells, and antibodies, are generated to target the antigen, leading to the destruction of the cancer cells. Therefore the development of an effective vaccine requires the ability to monitor both T cell and antibody responses to a defined antigen. In this respect, the successful development of robust, sensitive, and specific monitoring methodologies lies at the heart of the CVC.
The standardized monitoring employed by the CVC enables the comparison of single vaccine variables in simultaneous trials at many clinical centers. Variables being compared in the CVC vaccine trials include: the constitution of the antigen (protein, peptide, viral vectors, or DNA), the method, frequency, and intensity of antigen delivery, and the addition of adjuvants or immunostimulatory compounds (chemicals that enhance the immune response) (see diagram of Trials in Progress). The CVC approach of systematically testing different vaccines in parallel is without peer in academia and industry.