3589 Background: We planned to conduct a phase II clinical study of combination therapy with irinotecan and S-1, a new oral anticancer drug of the fluorinated pyrimidine type. We reported the interium reports of this study in colorectal cancer patients at GI cancer Symposium 2006. Methods: The antitumor effect was the primary endpoint, while the safety, progression-free survival time, and median survival time were the secondary endpoints. The subjects were untreated patients with inoperable advanced colorectal cancer aged 20–75 years. Irinotecan was administered at a dose of 100 mg/m2 (on days 1 and 15) as an intravenous infusion over 90 minutes, and oral S-1 (40 mg/m2) was administered after breakfast and dinner and then withdrawn for 2 weeks. Results: Forty patients were enrolled in the present study. There were 23 men and 17 women. The median age was 62 years (range: 34 to 74 years). Two patient showed grade 4 neutropenia, but the next course could be given safely after dose reduction. Three patients had grade 3 diarrhea, but therapy could be continued with addition of an antidiarrheal drug. No other serious adverse reactions occurred (either hematological or non-hematological), and all patients could receive therapy safely on an outpatient basis. Interim analysis suggested excellent results, with a response rate of 50%. To date, 231 cycles (median 8, range 1–19) have been administered. Median relative dose intensity was 97% for S-1 and 87% for irinotecan. 36 pts are evaluable for efficacy: RR was 47.2% (95% CI, 30.9–63.5%) and Disease Control Rate (PR + SD) was seen in 94.4% of pts. PFS of this regimen is 320 days. MST is not reached. Conclusions: IRIS therapy achieved a high response rate and could be given safely. These findings suggest that the therapy has potential as first-line treatment for inoperable advanced recurrent colorectal cancer. It seems that IRIS is a good treatment equal to FOLFIRI. In addition, this regimen could qualify as a candidate for future combination therapy with a molecular-targeting drug. The latest data will be reported at the meeting. No significant financial relationships to disclose.
A phase II clinical study of combining FOLFIRI and bevacizumab plus erlotinib in 2nd-line chemotherapy for patients with metastatic colorectal cancer
