SAN FRANCISCO, Jan. 17, 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 first scientific presentation of results from the Phase 1b portion of its ongoing ALPINE ( Antibody therapy in first- Line Pancreatic cancer Investigating anti- Notch Efficacy and safety) Phase 1b/2 clinical study of OMP-59R5 (anti-Notch 2/3) in patients with advanced pancreatic cancer. OMP-59R5 is part of OncoMed's collaboration with GlaxoSmithKline (GSK). These data were presented in a poster by Eileen M. O'Reilly, M.D., of Memorial Sloan-Kettering Cancer Center at the 2014 Gastrointestinal Cancers Symposium being held in San Francisco, California. "Pancreatic cancer has proven to be among the most challenging malignancies to treat," said Dr. O'Reilly. "The combination of OMP-59R5 with Abraxane and gemcitabine has been well tolerated and demonstrated positive signals of anti-cancer activity. We look forward to participating in the Phase 2 portion of the study." Two cohorts of patients in the dose-escalating study received OMP-59R5 in combination with gemcitabine, with remaining cohorts receiving OMP-59R5 in combination with gemcitabine and Abraxane ® (nab-paclitaxel). OMP-59R5 administered in combination with standard-of-care was well tolerated, with no dose-limiting toxicities observed up to 12.5 mg/kg. Adverse events, most commonly diarrhea, fatigue and nausea, were typically Grade 1 or 2, and easily managed with supportive care. The combination with gemcitabine and Abraxane did not significantly alter pharmacokinetics (PK) of OMP-59R5, and pharmacodynamic (PD) analyses demonstrated on-target activity against the Notch cancer stem cell pathway. Following the data cutoff point, dose escalation proceeded to 15 mg/kg and enrollment in the ALPINE study is ongoing. Twenty-one patients were evaluable for radiographic response. Thirteen of these 21 patients were treated with gemcitabine, Abraxane and OMP-59R5. Six of these thirteen patients (46%) treated with the three-drug combination achieved a RECIST partial response (PR) and an additional three patients achieved stable disease, for an overall disease control rate of 10 of 13 (77%). CA19-9 tumor blood marker values decreased by ≥ 50% from baseline among 10 of 13 (77%) patients in the OMP-59R5/gemcitabine/Abraxane cohorts.