Halozyme Announces Presentations Of Preclinical Data At The San Antonio Breast Cancer Symposium Annual Meeting

Halozyme Therapeutics, Inc.

announced that two scientific poster presentations on the pharmacology of PEGPH20 will be made at the 37th Annual San Antonio Breast Cancer Symposium (SABCS) today. The first of the presentations includes preclinical data showing that treatment of tumors with PEGPH20 enhances the action of immune-based cancer therapy such as monoclonal antibodies (mAbs). The second presentation includes additional supportive preclinical information on the utility of hyaluronan (HA) as a potential biomarker for cancer treatments. PEGPH20 is an investigational PEGylated form of rHuPH20 under development by Halozyme. PEGPH20 degrades the hyaluronan coating that may provide a supportive environment in many solid tumors. SABCS Poster Presentation Details Title: "Hyaluronan Depletion Sensitizes HAhigh Tumors to Antibody-Dependent Cell-Mediated Cytotoxicity" Poster Session: P5-04-02, December 12, 2014, 7:00AM - 7:00PM CDT Location: Exhibit Hall A-B Summary: About 50% of HER2+3 breast cancers and 12% of ovarian cancers accumulate abundant HA in the tumor microenvironment. The accumulation of HA is known to result in decreased access of therapeutics to the tumor. Therefore, HA accumulation may contribute to trastuzumab resistance. When HA is depleted by treatment with PEGPH20 in vitro, HAhigh/HER2+3 cells become much more sensitive to antibody-mediated cellular cytotoxicity. Additionally, HAhigh/HER2+3 human tumors in mice treated with PEGPH20 increased the access of trastuzumab and immune cells to the tumor, resulting in enhanced antitumor activity. These results suggest that co-administration of PEGPH20 could enhance the efficacy of trastuzumab in HAhigh/HER2+3 tumors. Title: "Naked Mole Rat HAS2 and Hyaluronan Are Not Tumor Suppressive in Human Tumor Xenografts" Poster Session: P4-04-25, December 12, 2014, 7:00AM - 7:00PM CDT Location: Exhibit Hall A-B Summary: Published third-party literature suggests that naked mole rat hyaluronan synthase 2 (nmrHAS2) produces extraordinarily high molecular weight HA, which has tumor suppressive effects. Transfection of the nmrHAS2 gene into human tumor cells did not suppress the growth of human tumors in nude mice and suggests that HA in the naked mole rat may have different functions than in human cancer, where HA accumulation promotes tumor growth.