Abstract 673: A Monoclonal Antibody, MORAb-075, Targeting Claudin-3 & Claudin-4 Inhibits human ovarian, pancreatic and prostate cancer progression in mice

Claudin (CLDN) is a family of integral membrane proteins. They are crucial for tight junction formation and functions. Studies have found CLDN3 and CLDN4 proteins are overexpressed in majority of primary ovarian, prostate, and pancreatic cancers. We have generated a rat-human chimeric monoclonal antibody, MORAb-075, which binds to CLDN3 and CLDN4 with high affinity in vitro. In order to evaluate its therapeutic potential in vivo, we have established a number of human cancer models where the tumors are grown orthotopically in nude mice. These tumors were confirmed positive for human CLDN3 or/and CLDN4 expressions via immunohistochemistry staining. The models include a CLDN3/4-expressing prostate cancer PC-3; a CLDN4-expressing pancreatic cancer, BxPc-3; a CLDN3-expressing ovarian cancer, IGROV-1. In these orthotopic tumor models, MORAb-075 demonstrated significant antitumor activities. When the mAb was administered intravenously at 25 mg/kg, twice weekly for 4 weeks, the tumor growth inhibition (TGI) of PC-3 tumors reached 50%; TGI of BxPC-3 tumors was nearly 60% and TGI of IGROV-1 tumors was greater than 75%. Our findings demonstrate the potency of MORAb-075, as a single agent, in inhibiting solid tumor growth in these models. These results suggest that mAb therapy targeting CLDN3 & CLDN4 is a valuable option for therapeutic application in cancer therapy that may be improved in combination with standard of care chemotherapies for CLDN3 or CLDN4 positive cancers. Citation Format: Jian-Min Lin, allis soto, Christopher maddage, earl Albone, yuhong zhou, luigi grasso. A Monoclonal Antibody, MORAb-075, Targeting Claudin-3 & Claudin-4 Inhibits human ovarian, pancreatic and prostate cancer progression in mice. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 673. doi:10.1158/1538-7445.AM2014-673