Phase I/II Study of SOL for Untreated Metastatic Colorectal Cancer

Introduction:
S-1 is promising drug which could replace 5-fluorouracil plus l-leucovorin (5-FU/l-LV) in treatment of advanced colorectal cancer.
Phase I/II study of S-1 plus Oxaliplatin (SOX) demonstrated its promising activity with acceptable toxicity as first-line chemotherapy in patients with untreated metastatic colorectal cancer and S-1 showed equivalent possibility to 5-FU/l-LV. On the other hand, phase I/II study of S-1 plus oral Leucovorin (S-1/LV) demonstrated that this regimen had enhanced efficacy in comparison with S-1 alone. From these results, it was expected that S-1/LV plus Oxaliplatin (SOL) would be more effective than SOX.
Therefore, phase I/II study of SOL combination therapy was planned.
Purpose A dose-finding study of S-1/LV plus Oxaliplatin (SOL) was planned to determine the recommended dose (RD), and to assess the response rate (RR) in patients with untreated metastatic colorectal cancer. The primary endpoints of the phase I portion are determination of the RD of SOL, and safety.
The phase II portion of this study was aimed to assess the RR of SOL.