OncoMed Pharmaceuticals, Inc. announced dosing of the first patient in a Phase 1b clinical trial of brontictuzumab (anti-Notch1, OMP-52M51) plus chemotherapy in patients with metastatic colorectal cancer. The Phase 1b trial is intended to determine the maximum-tolerated dose of brontictuzumab in combination with trifluridine/tipiracil (Lonsurf®).  The Phase 1b trial is designed to assess safety, preliminary efficacy and immunogenicity, as well as predictive and pharmacodynamics biomarkers.  Metastatic colorectal cancer patients who have received at least two prior lines of therapy will be enrolled in the dose-escalation portion of the trial, and once a maximum tolerated dose is identified, additional patients whose tumors test high for the activated form of Notch1 will be enrolled in an expansion cohort.