Expression of PRAME and MAGE-A3 in Asian and European patients with non-small cell lung cancer (NSCLC), bladder cancer, or hepatocellular carcinoma (HCC)

e13061 Background: Antigen (Ag)-specific cancer immunotherapy is based on induction of immune responses (humoral and cell-mediated) specifically targeting Ags expressed by tumor cells. This may be achieved by delivering the Ag as a recombinant protein combined with potent immunostimulants. PRAME and MAGE-A3 are tumor Ags with distinct tumor expression patterns, both under investigation as targets for immunotherapy in NSCLC and malignant melanoma. For additional clinical development of these immunotherapies in other cancer types, expression of PRAME and MAGE-A3 in these cancers must be investigated taking into account patient ethnicity and tumor characteristics. Methods: 4 retrospective studies were performed, each including all tumor stages: NSCLC pts (in Asia and Europe); bladder cancer pts in Europe; HCC pts in Asia. Formalin-fixed paraffin embedded tumor tissues were tested for PRAME and MAGE-A3 expression by quantitative RT-PCR using an expression cut-off value for positivity. Exploratory analyses of ...