Multicenter phase II study of FOLFOX for metastatic colorectal cancer (mCRC) in Japan; SWIFT-1 and 2 study.

Background/aims: This study assessed the efficacy and toxicity of the FOLFOX4 (SWIFT1) and mFOLFOX6 (SWIFT2) regimens in Japanese patients with metastatic colorectal cancer (mCRC).

Methodology: Patients with mCRC were required to have ECOG performance status of 0 to 1, and to have adequate organ function. Two multicenter Phase II studies (SWIFT1/SWIFT2) were conducted in chemotherapy naive patients with mCRC.

Results: 112 patients were enrolled in these studies (SWIFT1: 54 patients / SWIFT2: 58 patients). The disease sites for each study were the colon in 27 patients and 28 patients, and the rectum in 27 patients and 30 patients, respectively. All patients received a median of 8 courses. After a median follow-up period of 35 months, 54 patients and 58 patients were evaluable in the respective studies, and the overall response rate was 50.0% (CR:31 PR:53). The response rate according to the sites of metastasis were as follows: liver, 54.1% (46/85); lung, 17.4% (4/23); and lymph node, 23.3% (7/30). Grade 3/4 neutropenia occurred in 14 patients (12.5%), while Grade 3/4 non-hematological toxicities were observed in 16 patients (31.0%) and Grade 3 neurotoxicity was observed in 6patients (5.4%) and 5 patients (4.5%), respectively.

Conclusions: FOLFOX4 (SWIFT1) and mFOLFOX6 (SWIFT2) regimens complying with the international standard dosage and schedule can also be administered safely and effectively in Japan.