FOLFIRI + bevacizumab as second-line therapy for metastatic colorectal cancer pretreated with oxaliplatin: a pooled analysis of published trials

Irinotecan and infusional 5-fluorouracil-based chemotherapy (FOLFIRI) plus bevacizumab (FOLFIRI-B) is one of the most effective treatments of advanced colorectal cancer (CRC). However, this schedule is regarded more extensively as first-line therapy and its efficacy has not been proven in phase III randomised trials in oxaliplatin-pretreated patients. We have performed a systematic review through PubMed and EMBASE, including all prospective and retrospective publications exploring the efficacy of FOLFIRI-B as second-line chemotherapy in advanced CRC patients pretreated with oxaliplatin and not with B. Pooled estimates of the response rates (RR), weighted medians of progression-free survival (PFS), and overall survival (OS) from all FOLFIRI-B-containing arms were calculated. A total of 11 studies (one randomised phase II trial, two phase II trials, two observational studies, two prospective non-randomised collections, and four retrospective case series) were retrieved giving a total of 435 patients. Overall, the pooled RR (n = 11 publications) was 26 %. Median PFS and OS (n = 11 and 10 publications, respectively) were 8.3 and 17.2 months. FOLFIRI-B is a reasonable and effective option for stage IV CRC pretreated with oxaliplatin and not exposed to B during first-line treatment. Its activity seems better than historical FOLFIRI-based second-line trials.