REDWOOD CITY, Calif., Feb. 18, 2014 (GLOBE NEWSWIRE) -- OncoMed Pharmaceuticals, Inc. (Nasdaq:OMED), a clinical-stage company developing novel therapeutics that target cancer stem cells (CSCs), or tumor-initiating cells, today announced that it has started a multi-center Phase 1b clinical trial of OMP-54F28 (Fzd8-Fc) with sorafenib (Nexavar ®) in hepatocellular cancer (HCC). OMP-54F28 is a first-in-class Wnt-pathway-targeting decoy receptor and is part of OncoMed's collaboration with Bayer Pharma AG (Bayer). This is the second of three Phase 1b trials for OMP-54F28 to begin patient enrollment; earlier this year OncoMed initiated a Phase 1b of OMP-54F28 with nab-paclitaxel (Abraxane ®) and gemcitabine in pancreatic cancer. The Phase 1b clinical trial is a dose-escalation study of OMP-54F28 in combination with sorafenib in patients with first-line locally advanced or metastatic HCC. Primary objectives of the trial are to evaluate safety of this combination regimen and determine a recommended Phase 2 dose for OMP-54F28 in combination with sorafenib. Key secondary and exploratory objectives include evaluation of the pharmacokinetics (PK) and pharmacodynamics (PD) of OMP-54F28, as well as the efficacy of this combination. Tumor tissue from patients will be used to explore predictive biomarker hypotheses related to the efficacy of OMP-54F28. Safi Shahda, M.D., Assistant Professor of Clinical Medicine at Indiana University in Indianapolis, IN, is the principal investigator who treated the first patient enrolled in this study. Dr. Shahda commented, "Hepatocellular cancer is a devastating form of liver cancer that is a significant cause of cancer-related death worldwide. Patients with more advanced disease have very few treatment options. OMP-54F28 holds the potential to make a real difference for these patients as it was designed to attack so-called cancer stem cells that can generate new cancer cells and are particularly resistant to currently available cancer drugs." Five additional investigators and clinical sites are participating in this trial: Celina Ang, M.D., Mount Sinai Hospital, New York, NY; Crystal Denlinger, M.D., Fox Chase Cancer Center, Philadelphia, PA; Anthony El-Khoueiry, M.D., University of Southern California, Los Angeles, CA; Thomas Purcell, M.D., M.B.A., University of Colorado, Aurora, CO, and Andrew Zhu, M.D., Ph.D., Dana-Farber/Harvard Cancer Center, Boston, MA.