Phase II study of irinotecan combined with cisplatin in patients with previously untreated small-cell lung cancer. West Japan Lung Cancer Group.

PURPOSE

Irinotecan (CPT-11) is effective against small-cell lung cancer (SCLC) as monotherapy. Cisplatin is also a key drug against SCLC. We conducted a phase II study of CPT-11 combined with cisplatin to evaluate the efficacy and toxicity of this regimen in patients with previously untreated SCLC.

PATIENTS AND METHODS

Seventy-five patients with previously untreated SCLC were enrolled onto the study. CPT-11 60 mg/m2 was administered intravenously on days 1, 8, and 15 in combination with cisplatin 60 mg/m2 on day 1 every 28 days. Four courses of chemotherapy followed by thoracic irradiation were given to patients with limited disease (LD) and six courses to patients with extensive disease (ED).

RESULTS

The overall response rate was 84%, with a complete response (CR) rate of 29%. Forty patients with LD achieved an overall response rate of 83% and a CR rate of 30% and 35 patients with ED achieved an overall response rate of 86% and a CR rate of 29%. The median response duration was 8.0 months for LD patients and 6.6 months for ED patients. The median survival was 14.3 months for LD patients and 13.0 months for ED patients. The major grade 3 or 4 toxicities were neutropenia (77%), leukopenia (45%), diarrhea (19%), and anemia (39%). Two patients died with concomitant neutropenia and diarrhea.

CONCLUSION

This is a new active regimen for SCLC, especially ED-SCLC, with acceptable toxicity. A phase III study that compares CPT-11/cisplatin with etoposide/cisplatin for ED-SCLC is now being conducted.