SAN DIEGO, June 3, 2013 /PRNewswire/ -- Halozyme Therapeutics, Inc. (NASDAQ: HALO) today announced results from a Phase 1b trial of PEGPH20 (PEGylated Recombinant Human Hyaluronidase), an investigational new biologic, in combination with gemcitabine for the treatment of patients with stage IV metastatic pancreatic cancer. The full data will be presented today at the 2013 American Society of Clinical Oncology (ASCO) Annual Meeting in a poster session from 1:15 PM-5:15 PM CDT and during a discussion session from 4:45 PM-5:45 PM CDT (E Hall D1, Abstract #4010). (Logo: http://photos.prnewswire.com/prnh/20100302/LA63139LOGO) In this single-arm Phase 1b trial, the overall response rate (complete response + partial response) by RECIST 1.1 criteria was 42 percent (95% CI 22 - 62) for those treated at therapeutic dose levels of PEGPH20 (1.6 and 3.0 µg/kg) as assessed by an independent radiology review (n=24). Additionally, in subjects with high levels of hyaluronan (HA), a substance found in a protective matrix that surrounds many pancreatic cancers, the overall response rate was 64 percent (7 of 11 subjects with available biopsy). Moreover, 43 percent (6 of 14 subjects) saw a reduction of at least 70 percent in serum carbohydrate antigen 19-9 (CA 19-9), a biomarker which often correlates with tumor cell burden. 1 "Targeting the protective tumor matrix with an enzyme that digests hyaluronan is a novel treatment strategy for solid tumors. In addition to enabling chemotherapy drugs to penetrate more effectively into the tumor, removing hyaluronan may also slow its growth," said lead investigator Sunil Hingorani, M.D., Ph.D., Associate Member of the Clinical Research and Public Health Divisions at Fred Hutchinson Cancer Research Center. "Pancreatic cancer is one of the most challenging cancers to treat. We are encouraged by these early stage clinical data, and look forward to further testing the potential of PEGPH20 in randomized trials in combination with the most active regimens available for patients today." Halozyme announced in April the initiation of a Phase 2 study, a multicenter, randomized clinical trial evaluating PEGPH20 in combination with nab-paclitaxel and gemcitabine for the treatment of stage IV pancreatic cancer. Halozyme is also developing a HA diagnostic tool to evaluate potential treatment benefit based on tumor HA levels for use in the randomized Phase 2 trial. This HA-diagnostic approach may also enable the testing of PEGPH20 in other HA-rich tumor types.