Halozyme Issues New Preclinical Data at ASCO: PEGPH20 Boosted T-Cell Access to Tumor Cells in Animals

Halozyme Therapeutics, Inc.

, a biotechnology company developing novel oncology and drug-delivery therapies, today shared highlights of new data it presented at the American Association for Cancer Research (AACR) annual meeting. Halozyme also announced plans to present interim results of its randomized Phase 2 study in pancreatic cancer, Study 202, next month at the annual meeting of the American Society of Clinical Oncology (ASCO). In an oral presentation at the AACR meeting titled "Hyaluronan (HA) Depletion Increases Tumor Accessibility of T cell and Therapeutic PD-L1 Monoclonal Antibody in HA^high Tumors," findings in an animal model of non-small-cell lung cancer included: o Tumors with high levels of HA – a structural carbohydrate that accumulates in the areas surrounding cancer cells --form a natural HA-rich barrier that restricted T-cell access to tumor cells; o Halozyme's investigational new drug, PEGPH20, depletes HA and increases T-cells access to tumor cells in an animal models; o HA removal by PEGPH20 enhanced anti-PD-1 or anti-PD-L1 dependent tumor-cell killing in cell based assays; o HA depletion by PEGPH20 increased the access of T cell and anti-human PD-L1antibody in HA-high xenograft tumors, suggesting that PEGPH20 may have the potential to enhance the efficacy of immune checkpoint inhibitors in human HA-high tumors This new preclinical data adds to the growing body of evidence, generated in multiple animal tumor models, demonstrating increased efficacy when a range of different cancer therapeutics are administered with PEGPH20. Halozyme also presented findings relevant to the development of a companion diagnostic test for PEGPH20 in a poster presentation titled, "Development and Analytical Validation of a Novel Assay for Tissue Detection of Hyaluronan in the Tumor Microenvironment to Select Patients for Molecularly Targeted Pancreatic Cancer Therapies." These findings include: o Halozyme's companion diagnostic assay and proprietary HTI-601 binding probe were sensitive, specific and met the company's acceptability criteria for the detection and measurement of HA levels in archival samples from multiple different tumors types; and o HTI-601 may be appropriate as a companion diagnostic approach for the selection of patients with high HA levels suitable for therapy using PEGPH20. The company announced on April 8 plans to proceed with a Phase 3 clinical study (Study 301) of PEGPH20 in patients with metastatic pancreatic cancer using a companion diagnostic to prospectively identify patients with high levels of HA. "The findings we presented at AACR highlight the progress we are making with PEGPH20 development, with the preclinical data providing further support for the initiation of the planned combination trial with a PD1 inhibitor in non-small-cell lung cancer," said Athena Countouriotis, senior vice president and chief medical officer. "The evidence of HTI-601 as a sensitive and specific assay for HA was one of the key steps in our plans to have the companion diagnostic ready for Phase 3 initiation in the first quarter of 2016." Two additional poster presentations at AACR will be presented today (April 20): Title: "PEGPH20 Enhances Chemotherapy in Patient-Derived and Traditional Cell-Derived Xenograft NSCLC Models" Abstract #: 2547, April 20, 2015, 1:00PM - 5:00PM EDT (Poster) Location: Section 27, Poster 29 Title: "Hyaluronan-Dependent Growth of Human Triple Negative Breast Cancer MDA-MB-468 in Mouse Xenograft Models" Abstract #: 2392, April 20, 2015, 1:00PM - 5:00PM EDT (Poster) Location: Section 19, Poster 25