Overall Clinical Benefit Rate of 85%, Partial Response Rate of 42% and Progression Free Survival of 5.4 Months Observed in Patients with > 2 Prior Therapies and/or Prior Bevacizumab
REDWOOD CITY, Calif., Oct. 20, 2018 (GLOBE NEWSWIRE) -- OncoMed Pharmaceuticals, Inc. (NASDAQ:OMED), a clinical-stage biopharmaceutical company focused on discovering and developing novel anti-cancer therapeutics, today announced interim results from its ongoing Phase 1b trial investigating navicixizumab, OncoMed's anti-DLL4/VEGF bispecific antibody, in combination with paclitaxel in patients with platinum-resistant ovarian cancer.
The interim results were presented at the European Society for Medical Oncology in Munich. The patients had received a median of four prior therapies, all of whom had received prior paclitaxel and 69% had received prior bevacizumab. Twenty-two of the 26 patients (85%) treated with the novel regimen experienced clinical benefit. Notably 11 of the 26 patients (42%) achieved a partial response and the median progression-free survival was 5.4 months (95% CI: 3.5-8.0 months). Historical response rates for patients with heavily pretreated platinum-resistant ovarian cancer treated with chemotherapy are typically 15% or less.
"These are impressive results that warrant further evaluation in this historically difficult-to-treat patient population," said Kathleen Moore, M.D., Jim and Christy Everest Endowed Chair in Cancer Research, Clinical Research Director, University of Oklahoma Health Science Center and one of the lead investigators for the Phase 1b clinical trial. "When ovarian cancer stops responding to platinum-based therapy, our best option is chemotherapy plus bevacizumab, which may be effective, but often for only a short duration. Following this line of therapy, there are no approved, effective options for patients. Combination weekly paclitaxel and navicixizumab appears to provide durable responses among patients with multiple lines of prior therapy and/or prior exposure to bevacizumab, which represents a high unmet need."
The ongoing Phase 1b multicenter, open-label, dose-escalation and expansion trial is designed to assess the safety, preliminary efficacy, immunogenicity, pharmacokinetics and biomarker effects of navicixizumab plus paclitaxel. The trial has been expanded to enroll up to 60 patients with platinum-resistant ovarian cancer (including fallopian tube or primary peritoneal cancers) who have previously received bevacizumab and/or have failed at least two prior therapies.
Additional highlights from the poster were:
- The median number of prior therapies was four. All patients had previously received paclitaxel and 69% had received bevacizumab.
- The RECIST response rate was 42% and the RECIST response rate in the bevacizumab naïve and bevacizumab pretreated patients was 57% and 33%, respectively.
- CA-125 is a widely utilized tumor marker for ovarian cancer that is used along with radiographic assessments to determine the efficacy outcome to treatment. Of the 23 patients evaluable for a GCIG CA-125, 14 (61%) had a response. Specifically, the CA-125 response rates in the bevacizumab naïve and bevacizumab pretreated patients were 100% and 47%, respectively.
- The overall median progression free survival (PFS) was 5.4 months (95% CI: 3.5 — 8 months). The median PFS for the subset of bevacizumab pretreated patients was 3.7 months (95% CI: 3.3 months — not reached).
- The most common related adverse events of any grade related to navicixizumab were hypertension (53%), fatigue (32%), diarrhea (24%) and headache (18%). Other related rare adverse events of special interest were one Grade 2 pulmonary hypertension, one Grade 1 related heart failure, one Grade 4 related gastrointestinal perforation and one Grade 4 thrombocytopenia. Three patients (12%) experienced infusion reactions that were associated with anti-drug antibodies which impacted drug exposure.
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. In a Phase 1a study with single-agent navicixizumab published in Investigational New Drugs, 19 of 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.
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), and GITRL-Fc (OMP-336B11). 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 the potential of navicixizumab as a treatment for ovarian cancer patients previously treated with multiple lines of therapy and/or with bevacizumab, and the durability of responses to navicixizumab in such patients; and the ability of navicixizumab to induce potent anti-tumor responses while mitigating angiogenic-related toxicities. 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.