A phase II study with CPT-11 plus leucovorin and bolus IV 5-fluorouracil in patients with advanced colorectal carcinoma

Standard chemotherapy in advanced colorectal carcinoma (CRC) has not yet been established. The present study was conducted to assess the efficacy and toxicity profile of CPT-11, leucovorin (LV), and bolus 5-fluorouracil (5-FU) in a weekly schedule. Fifty-five patients were entered with no prior chemotherapy for advanced disease or adjuvant treatment ended at least 6 months preceding study entry, and 45 were assessable for response. Patients were treated with CPT-11 80 mg/m² (7 patients) or 70 mg/m² (48 patients). After completion of CPT-11 infusion, LV 200 mg/m² was administered over 2 hr followed immediately by 5-FU 450 mg/m², IV bolus, weekly for 6 weeks followed by a 2-week rest period. Treatment was continued for four cycles. Because of grade 3 and 4 diarrhea in four of the first seven patients, the study was amended to reduce the starting dose of CPT-11 from 80 to 70 mg/m² weekly. Four complete and 10 partial responses were observed (response rate: 25.5%), the median time to progression (TTP) was 7.7 months, 1-year survival rate was 62.3%, and the median overall survival was 15.0 months. Grade 3 and 4 diarrhea occurred in seven patients (12.7%), four of them treated with CPT-11 80 mg/m². Grade 3 myelotoxicity occurred in five patients (9.0%). Toxic death because of diarrhea, neutropenia, bacteremia, and sepsis occurred in a patient treated with CPT-11 80 mg/m². Our results confirm the efficacy of CPT-11, LV, and 5-FU in a weekly schedule in patients with advanced CRC. Further studies are needed to compare the present regimen with higher doses of CPT-11 with LV plus different schedules of 5-FU administration in the treatment of metastatic CRC.