Staining of MUC1 in ovarian cancer tissues with PankoMab-GEX detecting the tumour-associated epitope, TA-MUC1, as compared to antibodies HMFG-1 and 115D8.

PankoMab-GEX is a novel humanized and glycooptimized antibody, which recognizes a novel specific tumour epitope of MUC1 (TA-MUC1). The aim of this study was to evaluate PankoMab-GEX binding to a variety of ovarian cancer specimens (n=156) and to normal ovarian tissue. In addition, PankoMab-GEX staining was compared to that of the well-known anti-MUC1 antibodies HMFG-1 and 115D8. PankoMab-GEX showed positive reactivity in serous (100% of cases, mean IRS 8.23), endometrioid (95% of cases, mean IRS 6.40), mucinous (58% of cases, mean IRS 4.17), and clear cell (92% of cases, mean IRS 7.58) carcinomas. In contrast to HMFG-1, healthy ovarian tissue was not recognized by PankoMab-GEX. Staining with antibody 115D8 was increased with staging. Cytoplasmic PankoMab-GEX staining increased with tumour grade, but no correlation was found with staging. Univariate Kaplan-Meier analysis revealed a tendency of reduced survival of patients with high expression of TA-MUC1. The findings are encouraging with respect to a potential use of PankoMab-GEX as a new therapeutic antibody for the treatment of ovarian cancer patients.