Randomized phase II trial of cetuximab, bevacizumab, and irinotecan compared with cetuximab and bevacizumab alone in irinotecan-refractory colorectal cancer: the BOND-2 study

Abstract

Purpose: We evaluated the safety and efficacy of concurrent administration of two monoclonal antibodies, cetuximab and bevacizumab, in patients with metastatic colorectal cancer.

Patients and methods: This was a randomized phase II study in patients with irinotecan-refractory colorectal cancer. All patients were naïve to both bevacizumab and cetuximab. Patients in arm A received irinotecan at the same dose and schedule as last received before study entry, plus cetuximab 400 mg/m2 loading dose, then weekly cetuximab 250 mg/m2, plus bevacizumab 5 mg/kg administered every other week. Patients in arm B received the same cetuximab and bevacizumab as those in arm A but without irinotecan.

Results: Forty-three patients received cetuximab, bevacizumab, and irinotecan (CBI) and 40 patients received cetuximab and bevacizumab alone (CB). Toxicities were as would have been expected from the single agents. For the CBI arm, time to tumor progression (TTP) was 7.3 months and the response rate was 37%; for the CB arm, TTP was 4.9 months and the response rate was 20%. The overall survival for the CBI arm was 14.5 months and the overall survival for the CB-alone arm was 11.4 months.

Conclusion: Cetuximab and bevacizumab can be administered concurrently, with a toxicity pattern that seems to be similar to that which would be expected from the two agents alone. This combination plus irinotecan also seems to be feasible. The activity seen with the addition of bevacizumab to cetuximab, or to cetuximab plus irinotecan, seems to be favorable when compared with historical controls of cetuximab or cetuximab/irinotecan in patients who are naïve to bevacizumab.