Abstract 585: Assessing ENPP3 as a renal cancer target for bispecific T-cell engager (BiTE) therapy

Abstract

Abstract BiTE® therapeutics are single chain antibody constructs harboring two binding moieties: one directed at a tumor associated antigen and one directed at the CD3e protein, which trigger T cell dependent cellular cytotoxicity (TDCC) against targeted cancer cells. Here, we evaluated the suitability of ENPP3 as a potential BiTE® target. The ENPP3 mRNA is highly differentially expressed in clear cell Renal Cell Carcinoma (ccRCC) and the ENPP3 protein is detected with high uniformity and intensity in ccRCC tumor samples by immunohistochemistry. We demonstrated the surface expression of this protein in Renal Cancer cell lines and confirmed that the ENPP3 protein was highly restricted to the luminal side of normal epithelial layers in which it was detected (proximal renal tubules, bronchial epithelium, salivary glands). We developed highly potent anti-ENPP3 BiTE® molecules and demonstrated the in vitro TDCC activity of these molecules. Two anti-ENPP3 BiTE® molecules further demonstrated tumor formation inhibition activity in a human T cell / human target cell admixture mouse xenograft model. Citation Format: Olivier Nolan-Stevaux, Flordeliza Fajardo, Lily Liu, Suzanne Coberly, Patricia McElroy, Aaron Nazarian, Franziska Bott, Elisabeth Nahrwold, Tobias Raum, Roman Kischel, Ralf Lutterbuese, Patrick Hoffmann, Peter Kufer. Assessing ENPP3 as a renal cancer target for bispecific T-cell engager (BiTE) therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 585.