A multi-institutional feasibility study of S-1/oxaliplatin plus bevacizumab in patients with advanced/metastatic colorectal cancer: the HiSCO-02 prospective phase II study.

Objective: FOLFOX is a standard combination chemotherapy regimen for metastatic colorectal cancer (CRC). 5-Fluorouracil (5-FU) is infused continuously through a pump for 46 h; therefore, replacement of infused 5-FU with oral S-1 would be more convenient for patients. We investigated the efficacy and safety of S-1/oxaliplatin (SOX) plus bevacizumab regimen in a community setting.

Methods: We conducted a phase II clinical study in Hiroshima, Japan. We enrolled individuals aged 20-80 years who had metastatic CRC, an Eastern Cooperative Oncology Group performance status of 0 or 1, assessable lesions, and not received previous chemotherapy. Eligible patients were administered SOX plus bevacizumab (S-1 80 mg/m2/day, day 1-14 orally; and oxaliplatin 130 mg/m2 day 1 i.v., bevacizumab 7.5 mg/kg, day 1 i.v. q3w). The primary endpoint was response rate (RR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety.

Results: Between May 2011 and January 2014, 55 patients (mean age 64 years) were enrolled at 12 institutions. Median follow up duration was 20.2 months (range 1.3-47.1 months). RR was 47.1 % [95 % confidence interval (CI) 33.7-60.6 %]. Median PFS and OS was 9.2 months (95 % CI 7.6-10.8) and 22.5 months (95 % CI 19.4-25.9), respectively. Major adverse events (grade 3/4) were neutropenia (9.3 %), thrombocytopenia (5.6 %), anorexia (18.5 %), and sensory neuropathy (16.7 %).

Conclusions: These data suggested that SOX plus bevacizumab is effective and capable of being managed in metastatic CRC patients in our community clinical practice.