OncoMed Initiates Enrollment of Phase 1b Clinical

REDWOOD CITY, Calif., Jan. 04, 2017 (GLOBE NEWSWIRE) -- OncoMed Pharmaceuticals, Inc. (NASDAQ: OMED ), a clinical-stage company focused on discovering and developing novel anti-cancer stem cell and immuno-oncology therapeutics, today announced dosing of the first patient in a Phase 1b clinical trial of anti-DLL4/VEGF bispecific antibody (OMP-305B83) plus chemotherapy in patients with second-line metastatic colorectal cancer.

The anti-DLL4/VEGF is the first antibody developed utilizing OncoMed’s BiMAb™ bispecific platform technology and is designed to have anti-cancer stem cell, immunomodulatory and anti-angiogenic activity.  Thirty patients with metastatic colorectal cancer who have failed first-line treatment, typically bevicizumab plus FOLFOX (folinic acid, fluorouracil, oxaliplatin) chemotherapy, will receive second-line treatment in the Phase 1b multicenter, open-label dose escalation and expansion study of the anti-DLL4/VEGF bispecific antibody in combination with FOLFIRI (folinic acid, fluorouracil and irinotecan) chemotherapy.  This trial is designed to determine the safety, preliminary efficacy, immunogenicity, pharmacokinetics and biomarker effects of the anti-DLL4/VEGF bispecific antibody plus FOLFIRI.  A second Phase 1b study in patients with platinum resistant ovarian cancer is expected to begin enrolling patients soon.

"Metastatic colorectal cancer is an indication that we believe may benefit from the combined inhibition of DLL4 and VEGF plus chemotherapy," said Robert Stagg, Pharm.D., OncoMed’s Vice President, Clinical Research. “Anti-VEGF therapy plus 5-fluorouracil-based chemotherapy is currently approved in the treatment of second-line metastatic colorectal cancer, and this Phase 1b clinical trial is an opportunity to study the safety and preliminary efficacy of our anti-DLL4/VEGF bispecific antibody in combination with 5-fluorouracil-based chemotherapy and to observe if the multi-pronged mechanism of action may provide signs of enhanced activity.”

In an ongoing Phase 1a dose escalation and expansion study of OncoMed’s anti-DLL4/VEGF bispecific antibody as a single agent, interim data was presented on 51 patients with previously treated advanced solid tumors who were treated in the dose escalation portion of the trial.  Additional patients are currently being enrolled in the expansion phase of the study.  Anti-DLL4/VEGF bispecific antibody was generally well tolerated with hypertension, headache and pulmonary hypertension being the most common drug related toxicities.  Single-agent anti-tumor activity was observed: two of 46 evaluable patients had a partial response and 12 other patients had a reduction in their tumor volume.  One of the two colorectal patients on study had a reduction in tumor volume. ¹

About anti-DLL4/VEGF Bispecific Antibody (OMP-305B83) OncoMed’s anti-DLL4/VEGF bispecific antibody is designed to inhibit the function of both DLL4 and VEGF and thereby induce potent anti-tumor responses while mitigating certain angiogenic-related toxicities.  It 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 OncoMed's anti-DLL4/VEGF bispecific antibody 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 appears 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 company focused on discovering and developing novel anti-cancer stem cell and immuno-oncology therapeutics.  OncoMed has internally discovered a broad pipeline of investigational drugs intended to address the fundamental biology driving cancer’s growth, recurrence and metastases.  Demcizumab (anti-DLL4, OMP-21M18), tarextumab (anti-Notch2/3, OMP-59R5), anti-DLL4/VEGF bispecific antibody (OMP-305B83), vantictumab (anti-FZD7, OMP-18R5), ipafricept (FZD8-Fc, OMP-54F28), anti-RSPO3 (OMP-131R10) and an undisclosed immuno-oncology candidate (I/O#2) are part of the company’s strategic alliances with Celgene Corporation, Bayer Pharma AG and GlaxoSmithKline (GSK).  OncoMed is independently developing brontictuzumab (anti-Notch1, OMP-52M51) and GITRL-Fc, as well as continuing to pursue new drug discovery research efforts.  For further information about OncoMed Pharmaceuticals, please see www.oncomed.com .

¹ Jimeno, et al; “ A First-in-Man Phase 1a Study of the Bispecific Anti-DLL4/Anti-VEGF Antibody OMP-305B83 in Patients  with Previously Treated Solid Tumors;” 28 ^th EORTC-NCI-AACR Molecular Targets and Cancer Symposium

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 multi-pronged mechanism of action against tumors and anti-tumor synergy of dual inhibition of DLL4 and VEGF; the improved safety and anti-tumor efficacy of OncoMed’s anti-DLL4/VEGF bispecific antibody; and the ability of OncoMed’s anti-DLL4/VEGF bispecific antibody to provide a benefit to ovarian and colorectal cancer patients.  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 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 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 discover, develop and commercialize additional product candidates; 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 10, 2016, OncoMed's Quarterly Report on Form 10-Q filed with the SEC on November 1, 2016, and OncoMed's other periodic reports filed with the SEC.

Contact: Michelle Corral Senior Director, Investor Relations and Corporate Communications OncoMed Pharmaceuticals (650) 995-8373