A Phase II Study of Bevacizumab and Irinotecan Plus Alternate-Day S-1 As a Second-Line Therapy in Patients with Metastatic Colorectal Cancer: the AIRS Study

749 Background: The recommended dose of combination chemotherapy of irinotecan, bevacizumab and oral S-1 is 100mg/m2, 5mg/kg and 80-120mg/body respectively. To evaluate whether the dose of irinotecan could be raised to 150mg/m2 with modified administration of S-1, we have conducted a phase II study of irinotecan and bevacizumab plus alternate day S-1 in patients with metastatic colorectal cancer (UMIN000008947). Methods: Patients with metastatic colorectal cancer after failure with first-line treatment of oxaliplatine and fluoropyrimidine were enrolled. Irinotecan (150 mg/m2) and bevacizumab (5mg/kg) were given intravenously on day 1. Oral S-1was administered on alternate days at a dose of 40-60mg twice a day. Cycles were repeated every two weeks. Results: A total of 51 patients were evaluated in the first fouur cycles. Grade 3 and 4 neutropenia were 10% (10/51) and 13.7%(7/10), grade 3 and 4 thrombocytopenia were 0%(0/51) and 2.0% (1/51). Grade 2 and 3 mucositis were 13.7% (7/51) and 3.9% (2/51). Grade 2 and 3 nausea were 11.8% (6/51) and 2.0% (1/51). Grade 2 and 3 diarrhea were 17.6% (9/51) and 15.7% (8/51). The relative dose intensities were 84.8% for irinotecan, 87.5% for bevacizumab, and 84.8% for S-1 respectively in the first four cycles. Conclusions: Our data suggest that irinotecan (150 mg/m2) and bevacizumab was administered safely with alternate day S-1 as second-line tratment in patients with metastatic colorectal cancer. Clinical trial information: 000008947.