OncoMed Announces Publication of Phase 1a Data of Navicixizumab

REDWOOD CITY, Calif., Sept. 24, 2018 (GLOBE NEWSWIRE) -- OncoMed Pharmaceuticals, Inc. OMED, a clinical-stage biopharmaceutical company focused on discovering and developing novel anti-cancer therapeutics, today announced that the results of its Phase 1a study with single-agent navicixizumab in patients with refractory solid tumors were published in Investigational New Drugs. The results showed that 19 of the 66 patients with various types of refractory solid tumors had tumor shrinkage following treatment with navicixizumab. Notably, 3 of the 12 (25%) ovarian cancer patients treated in the trial achieved a partial response with single-agent navicixizumab therapy. Navicixizumab is a bispecific antibody that was designed to enhance the anti-tumor effect observed with inhibition of DLL4 or VEGF alone.

"These study results demonstrate that navicixizumab has single-agent anti-tumor activity in several tumor types and is particularly active in heavily pretreated ovarian cancer, a cancer with limited treatment options," said John Lewicki, Ph.D., President and Chief Executive Officer of OncoMed. "We look forward to presenting interim data from our Phase 1b study, which is evaluating navicixizumab in combination with paclitaxel in patients with heavily pretreated platinum-resistant ovarian cancer at the upcoming European Society of Medical Oncology meeting."

This Phase 1a multicenter, open-label, dose-escalation trial enrolled sixty-six patients with previously treated solid tumors. The primary endpoint was to determine the maximum tolerated dose. Secondary endpoints included safety, pharmacokinetics, immunogenicity and antitumor activity.

The most commonly enrolled tumor types were ovarian (12), colorectal (11) and cancers of the breast, pancreas, uterus and endometrium (four patients of each). Four patients (three ovarian cancer and one uterine carcinosarcoma) had a partial response, and 17 patients had stable disease. There were 19 patients that had a reduction in the size of their target lesions, including seven patients with ovarian cancer. Six of these seven ovarian cancer patients had prior bevacizumab. Four patients remained on study for >300 days and two of these patients were on study for >500 days. The most common drug related adverse events of any grade were hypertension (58%), headache (29%), fatigue (26%), and pulmonary hypertension (18%). Infusion reactions associated with anti-drug antibodies impacting drug exposure occurred in 11% of patients. The maximum tolerated dose for navicixizumab was not determined based on protocol-defined criteria, but doses of 3-4 mg/kg once every 2 weeks were chosen for the subsequent Phase 1b studies.

A Phase 1b multicenter, open-label, dose-escalation and expansion trial of navicixizumab in combination with paclitaxel in patients with platinum-resistant ovarian cancer who have previously received bevacizumab and/or have failed at least two prior therapies is ongoing. Interim study results will be presented in a poster presentation on October 20, 2018 at the European Society of Medical Oncology meeting to be held in Munich, Germany.

About Navicixizumab
OncoMed's anti-DLL4/VEGF bispecific antibody, navicixizumab, is designed to inhibit the function of both DLL4 and VEGF and thereby induce potent anti-tumor responses while mitigating certain angiogenic-related toxicities. Navicixizumab was developed utilizing OncoMed's BiMAb^™ bispecific platform technology, which enables the design of bispecific antibodies comparable to traditional monoclonal antibodies but possessing dual target-binding specificity. In preclinical studies, navicixizumab demonstrated robust in vivo anti-tumor efficacy across a range of solid tumor xenografts, including colon, ovarian, lung and pancreatic cancers, among others. Further, in preclinical studies dual inhibition of DLL4 and VEGF appeared to exhibit synergistic anti-tumor activity at doses where blockade of either target alone elicited sub-optimal activity.

About OncoMed Pharmaceuticals
OncoMed Pharmaceuticals is a clinical-stage biopharmaceutical company focused on discovering and developing novel anti-cancer therapeutics. OncoMed has internally discovered a broad pipeline of investigational drugs intended to address the fundamental biology driving cancer's growth, resistance, recurrence and metastasis. Product candidates in OncoMed's portfolio include navicixizumab (anti-DLL4/VEGF bispecific, OMP-305B83), etigilimab (anti-TIGIT, OMP-313M32), GITRL-Fc (OMP-336B11) and rosmantuzumab (anti-RSPO3, OMP-131R10). OncoMed also continues to pursue new drug discovery research. For further information about OncoMed Pharmaceuticals, please see 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, without limitation, OncoMed's intentions and expectations regarding navicixizumab's single-agent anti-tumor activity in several tumor types and ovarian cancer in particular; the ability of navicixizumab to induce potent anti-tumor responses while mitigating certain toxicities; the enhanced anti-tumor effect of navicixizumab relative to the inhibition of DLL4 or VEGF; and the timing of the reporting of data from the navicixizumab Phase 1b trial. 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; OncoMed's ability to raise additional capital to support the development of its unpartnered programs; and OncoMed's dependence on its key executives. 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 filed with the U.S. Securities and Exchange Commission (SEC) on March 9, 2018, OncoMed's Quarterly Report on Form 10-Q filed with the SEC on August 2, 2018, and OncoMed's other current and periodic reports filed with the SEC.