Background: Targeting the epidermal growth factor receptor and angiogenesis have proven useful strategies against metastatic colorectal cancer. The benefit of combining inhibitors of both pathways is unknown.
Patients and methods: Patients with previously untreated metastatic colorectal cancer were enrolled in a phase II trial of infusional 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX), bevacizumab and erlotinib. The primary end point was progression-free survival.
Results: Thirty-five patients were enrolled and all came off trial for reasons other than progression; 18 (51%) had protocol-defined adverse events requiring removal, nine (26%) withdrew consent due to toxicity, six pursued surgery or localized therapies and two requested a treatment holiday. Principal toxic effects included rash, neuropathy and diarrhea. Seven patients came off trial before first restaging. By intention-to-treat analysis, one patient had a confirmed complete response, 10 had confirmed partial responses and one had an unconfirmed partial response (response rate = 34%). One patient had progressive disease at time of withdrawal from the trial, thus progression-free survival could not be calculated.
Conclusion: The combination of FOLFOX, bevacizumab and erlotinib led to higher than expected early withdrawal due to toxicity, limiting conclusions regarding efficacy. These findings raise concern regarding the tolerability of adding more agents to already complex combination regimens for metastatic colorectal cancer.