Efficacy and safety of dilpacimab (ABT-165) versus bevacizumab plus FOLFIRI in metastatic colorectal cancer: a phase II study

Aim: This phase II study investigated safety and efficacy of dilpacimab or bevacizumab plus FOLFIRI in patients with previously treated metastatic colorectal cancer (mCRC). Materials & methods: Overall, 66 patients were treated (n = 34 dilpacimab + FOLFIRI; n = 32 bevacizumab + FOLFIRI). Progression-free survival, overall survival, response rates and tolerability were assessed. Results: Median progression-free survival for dilpacimab + FOLFIRI compared with bevacizumab + FOLFIRI was 3.78 months (95% CI: 2.07-7.20) versus 7.36 months (95% CI: 5.68-10.55) (hazard ratio: 3.57; 95% CI: 1.57-8.11; stratified). Median overall survival: 7.95 months for dilpacimab + FOLFIRI; not reached for bevacizumab + FOLFIRI. Objective response rates: 5.6% for dilpacimab + FOLFIRI and 14.7% for bevacizumab + FOLFIRI. Patients treated with dilpacimab + FOLFIRI experienced serious treatment-related adverse events (n = 4; 11.8%), including one case of intestinal perforation leading to death; none were reported for bevacizumab + FOLFIRI. Conclusion: Treatment with dilpacimab + FOLFIRI was not well tolerated and did not provide clinical benefit to patients with mCRC compared with bevacizumab + FOLFIRI. Clinical Trial Registration: NCT03368859 (Clinicaltrials.gov).