FDA Removes Partial Clinical Hold on OncoMed's Ipafricept

REDWOOD CITY, Calif.  -- OncoMed Pharmaceuticals, Inc. (Nasdaq:OMED), announced today that the U.S. Food and Drug Administration (FDA) removed the partial clinical hold on the company's ipafricept (FZD8-Fc, OMP-54F28) Phase 1 clinical trials. Enrollment and dosing of new patients is expected to resume within the next few weeks as the study sites' institutional review boards (IRBs) receive and approve the revised trial protocols. Ipafricept is being studied in combination with standard-of-care in three Phase 1b studies.

"With important input from our clinical investigators and academic bone experts, the OncoMed team has developed modified study parameters intended to avoid potential risks while allowing us to evaluate the therapeutic impact of ipafricept for patients with pancreatic, hepatocellular and ovarian cancers in combination with standard therapy," said Jakob Dupont, MD, OncoMed's Chief Medical Officer. "We appreciate the FDA's prompt response to our submission and their acceptance of our proposed amendments to the trial protocols."

OncoMed submitted a substantial clinical safety and efficacy data package for ipafricept along with revised study protocols to the FDA's Division of Oncology Products 1, which resulted in the removal of the partial clinical hold. The amendments for the Phase 1b combination trials include modified dosing regimens, risk mitigation measures, such as increased monitoring and bone protection strategies, and modified enrollment criteria.

"We expect enrollment in our first-in-class Wnt pathway programs, ipafricept and vantictumab, to be back underway soon," said Paul J. Hastings, Chairman and Chief Executive Officer of OncoMed. "The Wnt pathway represents a highly promising target for disrupting cancer stem cell activity and inducing tumor differentiation. As we advance ipafricept and vantictumab through clinical studies in combination with standard of care, we expect to generate key data from these Phase 1b studies that will support a potential opt-in by our partner Bayer as well as late-stage clinical development."

On June 13, 2014, OncoMed announced its decision to voluntarily halt enrollment in its Phase 1 vantictumab and ipafricept Wnt pathway programs as a precautionary measure based on reported incidents (13% and 5%, respectively) of mild-to-moderate bone adverse events. The FDA concurred with the company's decision and placed the studies on partial clinical hold, allowing for the continued dosing of patients who demonstrated benefit without significant drug-related adverse effects. The FDA removed the partial clinical hold on both programs based on data and amended study protocols submitted by OncoMed.

About Ipafricept (Fzd8-Fc, OMP-54F28)

Ipafricept (Fzd8-Fc, OMP-54F28) is a first-in-class fusion protein that inhibits a key signaling pathway in cancer, the Wnt pathway. Ipafricept selectively binds Wnt ligands that are activators of Wnt signaling. Ipafricept has shown broad anti-CSC and anti-tumor activity in patient-derived xenograft tumor models. In a single-agent Phase 1a study in patients with advanced solid tumors, ipafricept was well tolerated and demonstrated on-target Wnt pathway modulation (ASCO 2014). OncoMed is conducting three Phase 1b clinical trials of ipafricept: one in pancreatic cancer (Abraxane®+gemcitabine + ipafricept), one in hepatocellular carcinoma (sorafenib + ipafricept), and one in platinum-sensitive ovarian cancer (carboplatin/paclitaxel + ipafricept). Ipafricept is part of OncoMed's collaboration with Bayer.

About OncoMed Pharmaceuticals

OncoMed Pharmaceuticals is a clinical-stage company focused on discovering and developing novel therapeutics targeting cancer stem cells (CSCs). OncoMed has five anti-cancer product candidates in clinical development, including demcizumab (anti-DLL4, OMP-21M18), tarextumab (anti-Notch2/3, OMP-59R5), anti-Notch1 (OMP-52M51), vantictumab (anti-FZD7, OMP-18R5), and ipafricept (FZD8-Fc, OMP-54F28), which target key cancer stem cell signaling pathways including Notch and Wnt. OncoMed has two other antibodies in preclinical development, anti-DLL4/anti-VEGF bispecific (OMP-305B83) and anti-RSPO3 (OMP-131R10), with Investigational New Drug filings planned for late 2014 or early 2015. OncoMed is also pursuing discovery of additional novel anti-CSC and cancer immunotherapy product candidates. OncoMed has formed strategic alliances with Celgene Corporation, Bayer Pharma AG and GlaxoSmithKline (GSK). Additional information can be found at the company's website: www.oncomed.com.

Forward-Looking Statements

To the extent that statements contained in this press release are not descriptions of historical facts regarding OncoMed Pharmaceuticals, they are forward-looking statements reflecting the current beliefs and expectations of management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, including OncoMed's expectations regarding the ability of OncoMed to advance ipafricept and vantictumab in clinical development; the acceptability of the amended ipafricept and vantictumab protocols by the institutional review boards; OncoMed's ability to resume enrollment and dosing of patients in the Phase 1b trials for ipafricept and vantictumab; the timing of resumption of enrollment and dosing of new patients in the ipafricept and vantictumab Phase 1b trials; the ability of the revised protocols to mitigate the risks of future adverse events in ipafricept and vantictumab clinical trials;the potential of ipafricept and vantictumab to impact treatment and the clinical outcome of patients with cancer; the potential for Bayer to exercise their options on the ipafricept and vantictumab programs; and the timing of Investigational New Drug filings for OncoMed's anti-DLL4/anti-VEGF bispecific and anti-RSPO3 antibodies. Such forward-looking statements involve substantial risks and uncertainties that could cause OncoMed's clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, the uncertainties inherent in the preclinical and clinical development process; the risks and uncertainties of the regulatory approval process; OncoMed's dependence on its collaboration partners, including Celgene, GSK and Bayer, for the funding of its partnered programs; OncoMed's ability to raise additional capital to support the development of its unpartnered programs; OncoMed's dependence on the development and marketing efforts of its partners for the commercial success of its partnered product candidates; OncoMed's reliance on third parties to conduct certain preclinical studies and all of its clinical trials; OncoMed's reliance on single source third-party contract manufacturing organizations to manufacture and supply its product candidates; OncoMed's ability to validate, develop and obtain regulatory approval for companion diagnostics; OncoMed's ability to achieve market acceptance and commercial success of its product candidates once regulatory approval is achieved; OncoMed's ability to discover, develop and commercialize additional product candidates; the ability of competitors to discover, develop or commercialize competing products more quickly or more successfully; OncoMed's dependence on its Chairman and Chief Executive Officer, its Chief Scientific Officer, its Chief Medical Officer and other key executives; risk of third party claims alleging infringement of patents and proprietary rights or seeking to invalidate OncoMed's patents or proprietary rights; and the ability of OncoMed's proprietary rights to protect its technologies and product candidates. OncoMed undertakes no obligation to update or revise any forward-looking statements. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to OncoMed's business in general, see OncoMed's Annual Report on Form 10-K for the fiscal year ended December 31, 2013, filed with the Securities and Exchange Commission (SEC) on March 18, 2014, OncoMed's Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2014, filed with the SEC on May 8, 2014,and OncoMed's Quarterly Report on Form 10-Q for the fiscal quarter ended June 30, 2014, filed with the SEC on August 7, 2014.

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