A phase II trial of salvage treatment with gemcitabine and S-1 combination in heavily pretreated patients with metastatic colorectal cancer.
3595 Background: We conducted a phase II trial of gemcitabine with S-1 to evaluate the activity and toxicity of such a combination in heavily pre-treated patients (pts) with metastatic colorectal cancer (mCRC) who have progressed after treatment with fluoropyrimidines-, oxaliplatin- and irinotecan-containing regimens. Methods: 36 pts were enrolled, with the following characteristics: 19 females (53%), median age 57 (28-72), 30 EOGO PS 0-1 (83%). S-1 was given orally (30 mg/m2) b.i.d for 14 consecutive days and gemcitabine (1000 mg/m2) was given on days 1 and 8, every 21 days, until disease progression and for a maximum of 9 cycles. The primary endpoint was objective response rate (ORR). Results: The median number of cycles was 5 (range 1-9), ORR was 16.7% (95% confidence interval [CI] 4.5-28.9%) and disease control rate was 61.1% (95% CI 45.2-77.0%) with 6 partial responses and 16 stable diseases. Median duration of disease control was 5.8 months (95% CI 4.1-7.5 months). Median progression-free survival was 3.7 months (95% CI 2.2-5.2 months) and median overall survival was 10.0 months (95% CI 7.4-12.7 months). Grade 3-4 toxicities were rare (neutropenia 12%, anemia 11%, leucopenia 6%, thrombocytopenia 3% and diarrhea 3%). Conclusions: Combination chemotherapy with gemcitabine and S-1 was a convenient, well tolerated and efficacious for heavily pre-treated pts with mCRC. This regimen warrants further evaluation in pts with good PS but no further treatment options.