SAN DIEGO, Oct. 22, 2013 /PRNewswire/ -- Halozyme Therapeutics, Inc. (NASDAQ: HALO) today announced the initiation of a Phase 1b/2 randomized clinical trial (S1313) of Halozyme's investigational drug PEGPH20 (PEGylated Recombinant Human Hyaluronidase) in combination with modified FOLFIRINOX chemotherapy (mFOLFIRINOX) compared to mFOLFIRINOX treatment alone in patients with metastatic pancreatic adenocarcinoma. The trial, which will enroll approximately 144 patients, is being sponsored by SWOG, a cancer research cooperative group of more than 4,000 researchers in over 500 institutions around the world. (Logo: http://photos.prnewswire.com/prnh/20100302/LA63139LOGO) "Existing PEGPH20 data are intriguing, and warrant further investigation and comparison to the current standards of care to better understand its safety and efficacy profile," said trial investigator Philip A. Philip, M.D., Ph.D., Clinical Professor of Oncology at the Barbara Ann Karmanos Cancer Institute. The initial Phase 1b run-in arm of the trial is designed to confirm the optimal dose of PEGPH20 for the Phase 2 portion of the trial. The primary endpoint from Phase 2 is overall survival (OS) of patients receiving mFOLFIRINOX in combination with PEGPH20 compared to those receiving mFOLFIRINOX alone. Secondary endpoints include progression free survival (PFS), objective tumor response as well as the frequency, severity and tolerability of adverse events. Additional evaluations include expression of tumor target hyaluronan (HA) in patient biopsies. "Despite recent advancements, pancreatic cancer still has one of the lowest survival rates of any malignancy. The S1313 trial, coupled with our internally sponsored Phase 2 trial of PEGPH20 in combination with nab-paclitaxel and gemcitabine, will provide important safety and efficacy data on the potential of PEGPH20 in combination with the most advanced chemotherapeutic regimens available to patients with pancreatic cancer today," said Gregory I. Frost, Ph.D., President and Chief Executive Officer, Halozyme Therapeutics. Additional Study Details The Phase 1b run in portion of the S1313 study will be a limited dose de-escalation clinical trial examining the dose-limiting toxicities (DLT) in six evaluable patients to identify the optimal dose for PEGPH20 in the Phase 2 study. The Phase 2 portion will be a randomized, multicenter, parallel arm study enrolling approximately 138 evaluable patients. In addition to the endpoints of the study described above, the study will also explore the treatment impact on carbohydrate antigen 19-9 (CA 19-9), a biomarker often associated with tumor cell burden 1, as well as the correlation of plasma hyaluronan (HA) and tumor HA with OS, PFS and overall response rate (ORR). The mFOLFIRINOX treatment regimen consists of oxaliplatin, leucovorin, irinotecan and 5-fluorouracil. Additional study details can be found at http://www.clinicaltrials.gov using the study identifier NCT01959139. In April 2013, Halozyme initiated a Phase 2 multicenter, randomized clinical trial of nab-paclitaxel and gemcitabine with and without PEGPH20 to assess the combination treatment effect as measured by ORR, PFS and OS. The study is expected to enroll approximately 124 patients with stage IV pancreatic ductal adenocarcinoma. Halozyme is also developing an HA diagnostic tool to evaluate the potential treatment benefit based on tumor HA levels at baseline. This diagnostic approach may enable additional PEGPH20 combination clinical studies in other HA-rich tumor types. Additional information about this trial can be found at http://www.clinicaltrials.gov using the study identifier NCT01839487. About PEGPH20 PEGPH20 is an investigational PEGylated form of Halozyme's proprietary recombinant human hyaluronidase under development for the systemic treatment of tumors that accumulate hyaluronan (HA). Emerging data show that most pancreatic cancers surround themselves with a protective hyaluronan-rich matrix, which makes the disease difficult to treat and is an indicator of poor prognosis. PEGPH20 has been shown to deplete this matrix component from the tumor that rapidly changes the tumor microenvironment and metabolism, which may render the tumor more vulnerable to therapy as well as inhibit tumor growth.