Phase Ib study of drozitumab combined with first-line FOLFOX plus bevacizumab (BV) in patients (pts) with metastatic colorectal cancer (mCRC).

546 Background: Drozitumab is a monoclonal antibody that triggers tumor cell apoptosis by selective agonistic interaction with the Apo2 ligand/TNF-related apoptosis-inducing ligand death receptor 5. This study assessed the safety of drozitumab combined with FOLFOX+BV as first-line therapy in mCRC pts. Methods: Multicenter, open-label study of 2 sequential dose cohorts. Cohort 1 = 3.5mg/kg after 5 mg/kg loading dose (n=3); Cohort 2 = 7mg/kg after 10mg/kg loading dose (n=6). Pts were treated on 14-day cycles (drozitumab, FOLFOX, and BV 5mg/kg on Day 1 of cycle) until disease progression or toxicity. Dose-limiting toxicity (DLT; primary outcome measure) was assessed through 2 cycles (Days 1-28). Adverse events (AE) were recorded through all cycles. Response was assessed by RECIST. Results: A total of 9 pts received 1-22 cycles (median 11) of drozitumab. No DLTs occurred. Most frequent AEs were neutropenia (89%), diarrhea (78%), nausea (78%), fatigue (67%), and anemia (56%). Most frequent Grade ≥3 AEs were fa...