Background/aims: S-1 combination with oxaliplatin and oral leucovorin (SOL regimen) demonstrated well tolerability and efficacy in Japanese patients with metastatic colorectal cancer. The present study was conducted to confirm the safety and efficacy of SOL regimen in Chinese patients with untreated metastatic colorectal cancer.
Methodology: We planned to enroll 20 untreated, unresectable or recurrent advanced colorectal adenocarcinoma patients. The treatment schedule comprised S-1 40-60 mg bid and leucovorin (LV) 25 mg bid for one week and 2 hour drip infusion of oxaliplatin (L-OHP) 85 mg/m2 on day 1, 1 week off, repeated every 2 weeks. The primary study endpoints were safety. Secondary endpoints were overall response rate (ORR), progression free survival (PFS) and time to treatment failure (TTF).
Results: A total of 21 patients (median age: 65; range: 30-79) were enrolled between August 2009 and December 2009. There were 15 patients with colon cancer and 6 with rectal cancer. Data cut-off date was April, 2011. In total, 168 cycles were administered (median 7 per patient; range 1-19). The common toxicities were neutropenia, thrombocytopenia, fatigue, diarrhea, nausea/vomiting, peripheral neurotoxicity and anemia. The common grade 3/4 adverse events were diarrhea (19.1%), thrombocytopenia (9.5%) and nausea/vomiting (9.5%). Dose-adjusted was executed in 11 patients owing to AEs, including S-1 in 9 cases and L-OHP in 9 cases. Death due to adverse event was not observed. Responses were evaluated in 20 patients with measurable disease, the overall response rate was 45% (1 CR and 8 PR: 95% CI, 23-68%) and the disease control rate was 70% (95% CI, 46%-88%). Pathologic complete response was observed in 1 patient after 5 cycles of treatment. Median PFS was 9.0 (95% CI, 3.7- 14.4) months. Median TTF was 4.2 (95% Cl, 3.5-5.6) months.
Conclusions: This result indicates that the SOL regimen is well tolerated and effective in Chinese patients with metastatic colorectal cancer.
Trial registration: ClinicalTrials.gov NCT01110941.