OVAREX MAb-B43.13:IFN-gamma could improve the ovarian tumor cell sensitivity to CA125-specific allogenic cytotoxic T cells.
Various immunological parameters were studied in 100 ovarian cancer patients injected with the OVAREX therapeutic vaccine (the functional component of which is anti-CA125 MAb-B43.13) to explain the serendipitous observation of prolonged survival after such treatment. In addition to CA125-specific humoral and cellular responses, interferon-gamma (IFN-gamma) was also found to be induced in those patients receiving the vaccine. In vitro studies indicated that the expression of MHC I, MHC II, and ICAM I in ovarian tumor cells were upregulated in response to IFN-gamma. Such tumor cells were also found to be more sensitive to CA125-specific cytotoxic T cells compared to cells that were not incubated with IFN-gamma.