During allergy season your eyes start to itch, your nose runs, and you sneeze incessantly. This is all because your body recognizes allergens -- anything from pet dander to ragweed -- as unwanted foreign bodies, or antigens. Antigens cause your immune system to produce antibodies to fight what it believes to be a threat. A new patent has harnessed this same idea of self-defense to fight cancer cells.
Scientists at the Sloan-Kettering Institute for Cancer Research in New York, with the help of some funding from the National Institutes of Health, have developed a polyvalent conjugate vaccine for cancer, aimed at inducing an immune response, characterized by antibody production, in patients with breast, prostate, ovarian and small cell lung cancers. The claimed method comprises administering a pharmaceutically effective amount of the vaccine to target tumor-specific antigens. In response to the vaccine, most patients during the clinical studies generated high titer (meaning high concentrations of) 1gM or 1gG antibodies against the respective antigen conjugates.
In general, the immune response can be targeted in two distinct ways: non-specific immunopotentiation, which constitutes the bulk of past and current efforts in cancer immunotherapy; and specific immunization, which has not been significantly evaluated in the treatment of cancer but which has contributed greatly to the control of infectious diseases. While well-documented knowledge of microbial antigens has allowed for development of successful specific immunization against infections, the lack of understanding of human cancer antigens has prevented exploration of specific immunization as it pertains to cancer treatment.
Yet, the researchers behind this patent have discovered that, while carbohydrate antigens are the only defined bacterial antigens used in vaccines against bacterial pathogens, they are also applicable to cancer vaccinations. Immunization with carbohydrate antigens has resulted in directed antibody responses against human tumor cells. This reaction is believed to be caused by these antibodies’ mediation of antibody-dependent cell-mediated and complement-mediated lysis of tumor cells, complement-induced inflammation, and phagocytosis by the reticulo-endothelial system.
Targeted patient populations for this vaccination have failed primary therapies, such as surgery or radiation, and are seeking an alternate method for treating and preventing disease progression. This new vaccine presents a potentially viable option for helping patients’ bodies help themselves in the fight against cancer.
