REDWOOD CITY, Calif., July 2, 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 issuance of a broad U.S. patent relating to FZD-Fc soluble receptors, including OncoMed's clinical-stage candidate ipafricept (FZD8-Fc, OMP-54F28). The new patent, U.S. Patent No. 8,765,913, includes claims covering certain FZD-Fc compositions of matter, as well as claims covering methods of treating cancer with such soluble receptors. Polynucleotides encoding the claimed FZD-Fc polypeptides and cells producing such polypeptides are also covered. In addition to the FZD-Fc patent announced today, OncoMed has previously been granted U.S. patents that relate to FZD-Fc soluble receptors including U.S. Patent Nos. 7,723,477 and 8,324,361. Related patents have also issued in Japan and Australia, and OncoMed has filed related applications which are pending in Europe and certain additional foreign countries. "We expect that this new patent will provide an additional layer of protection for our ipafricept program, as well as further strengthen OncoMed's growing intellectual property position in the Wnt/FZD field," said Paul J. Hastings, OncoMed's Chairman and Chief Executive Officer. Ipafricept is a fusion protein comprising a portion of the human FZD8 receptor and a human immunoglobulin Fc domain. The product candidate acts as a decoy receptor that inhibits Wnt signaling by binding Wnt ligands that are activators of Wnt signaling. In preclinical studies, FZD8-Fc has demonstrated anti-tumor activity in a variety of patient-derived xenograft models. FZD8-Fc is currently in Phase 1a and 1b clinical development and is part of OncoMed's collaboration with Bayer. OncoMed presented Phase 1a data from the first-in-human study of ipafricept in refractory solid tumor patients in an oral presentation at the 2014 Annual Meeting of the American Society of Clinical Oncology (ASCO). In 26 refractory patients, single-agent ipafricept was tolerated with mild-to-moderate dysgeusia (taste change), muscle cramps and nausea as the most common adverse events. Additionally, one moderate bone adverse event occurred. Nine of 26 patients achieved disease control for at least 100 days. Later in June, OncoMed voluntarily halted clinical studies of ipafricept as a precautionary measure following some reports of mild-to-moderate bone adverse events. The Division of Oncology Products 1 of the U.S. Food and Drug Administration concurred with OncoMed's actions and placed a partial clinical hold on ipafricept studies. OncoMed plans to submit amended protocols to the FDA incorporating modified dosing regimens, updated risk mitigation measures and revised enrollment criteria. Enrollment and dosing of new patients in the Phase 1b trials are expected to resume once protocol amendments complete the process of review by the FDA and are approved by the study sites' institutional review boards.