How ASCI is believed to work

ASCI is believed to be able to ‘teach’ the immune system to recognize antigens on the surface of cancer cells and to stimulate an immune response against them that is strong enough to eradicate the tumor. GSK is currently evaluating this in clinical trials.

This is thought to be achieved by:

• the careful selection and presentation of antigens: ASCI includes antigens that are selectively expressed by tumor cells but not (or only at low levels) by normal cells.
• the induction of an effective immune response: when the immune system wants to destroy damaged or infected cells, it does it by sending killer T-cells. Therefore, in order for the immune system to be able to kill cancer cells, ASCI should stimulate an immune response that primes or activates T-cells against the antigens the cancer cells display, and increases the number of these T-cells. These T-cells should then be able to destroy all the cancer cells displaying the antigen, resulting in regression of the tumor. [Baxevanis et al., 2000, #5176; Boon et al., 2006, #14524; Brichard and Gerard, 2003, #32318; Janssen et al., 2003, #59481].

The nature and effectiveness of the immune response that cancer immunotherapy induces can be influenced, both by the antigen used and by the addition of specific immunological Adjuvant Systems. In the formulation of ASCI, antigen and Adjuvant Systems have been matched in order to maximize the quantity and quality of the immune response against cancer cells.

Because different types of cancer may express the same antigen (shared antigen), ASCI has the potential to be used to treat different tumors. Patients will only be selected for treatment if their cancer expresses the antigen used in the ASCI.