REDWOOD CITY, Calif., Feb. 20, 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 the initiation of patient treatment for its third multi-center Phase 1b clinical trial of OMP-54F28 (Fzd8-Fc) with carboplatin and paclitaxel in patients with platinum-sensitive ovarian cancer. OMP-54F28 is a first-in-class decoy receptor targeting the Wnt pathway and is part of OncoMed's collaboration with Bayer Pharma AG (Bayer). With the commencement of this clinical study, all six of OncoMed's planned Phase 1b clinical trials for its proprietary Wnt-pathway-targeting compounds, vantictumab (OMP-18R5) and OMP-54F28, are now enrolling patients. Earlier this year OncoMed initiated two separate Phase 1b clinical trials of OMP-54F28 with nab-paclitaxel (Abraxane ®) and gemcitabine in pancreatic cancer, and with sorafenib (Nexavar ®) in hepatocellular cancer. During the fourth quarter of 2013, OncoMed initiated three Phase 1b trials for its anti-Frizzled antibody, vantictumab; in combination with paclitaxel in breast cancer, with nab-paclitaxel and gemcitabine in pancreatic cancer, and with docetaxel in non-small cell lung cancer. "With the initiation of our Phase 1b study of OMP-54F28 in ovarian cancer, we have now achieved our goal of six open Phase 1b combination trials for our two anti-cancer stem cell clinical candidates that target the Wnt pathway," said Paul J. Hastings, OncoMed's Chairman and Chief Executive Officer. "Both candidates have demonstrated promising early data and these Phase 1b combination studies will provide critical data for Bayer to exercise their option to license OMP-54F28 and vantictumab and for the planning and execution of Phase 2 clinical studies." The Phase 1b clinical trial of OMP-54F28 in combination with carboplatin and paclitaxel is a dose-escalation study in patients with recurrent platinum-sensitive ovarian cancer. 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 carboplatin and paclitaxel. 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.