Phase II study of oxaliplatin combined with S-1 and leucovorin (SOL) for Chinese patients with metastatic colorectal cancer

Abstract Background Fluoropyrimidine and oxaliplatin are widely used for patients with colorectal cancer. This phase II study was conducted to evaluate the efficacy and safety of the combination of S-1, oxaliplatin, and leucovorin (SOL) in the treatment of Chinese patients with metastatic colorectal cancer (mCRC). Methods Eligible patients with untreated mCRC from four hospitals in China received intravenous oxaliplatin (85 mg/m2) on day 1, oral S-1 twice daily (80–120 mg per day) on day 1–7, and leucovorin twice daily (50 mg per day) simultaneously with S-1, every 2 weeks. Results and discussion Forty patients were enrolled in our study. In total, 296 cycles of SOL were administered. The overall response rate was 50.0%. At a median follow-up of 27 months, progression-free survival and overall survival were 7.0 months (95% confidence interval [CI] 6.0–10.6 months) and 22.2 months (95% CI 15.1–29.3 months), respectively. The most common grade 3/4 non-hematological adverse events were diarrhea (n = 8, 20.0%), nausea (n = 3, 7.5%), and vomiting (n = 3, 7.5%). The most common grade 3/4 hematological toxicities were thrombocytopenia (n = 3, 7.5%), neutropenia (n = 1, 2.5%), and abnormal alanine transaminase/aspartate transaminase levels (n = 1, 2.5%). There was one treatment-related death. Conclusions The data indicate that the SOL regimen is effective and moderately tolerated in Chinese patients with mCRC. Trial registration: Clinical trial information: ChiCTR-TNRC-100000838