A phase II study of irinotecan and docetaxel combination chemotherapy for patients with previously treated metastatic or recurrent advanced gastric cancer

Irinotecan (I) and docetaxel (D), each of which has a unique mechanism of action, were recently introduced in the treatment of patients with advanced gastric cancer (AGC). We have evaluated the efficacy and safety of the ID combination for AGC patients after failure of fluoropyrimidine- or platinum-based chemotherapy.

Patients with relapsed or progressive AGC after prior fluoropyrimidine- or platinum-based chemotherapy were treated with I (160 mg/m², 90 min) followed by D (65 mg/m², 1 h) every 3 weeks. Because of the unacceptable toxicity among the first ten patients, the doses were reduced for I (120 mg/m²) and D (50 mg/m²) every 3 weeks.

Forty-nine patients, of median age 53 years (range, 27–68 years), were treated with 170 cycles of chemotherapy (median, 2 cycles; range, 1–12 cycles). Three patients achieved complete response and seven achieved partial response, resulting in an overall response rate (ORR) of 20.4% [95% confidence interval (CI), 9.1–31.7%], with a median duration of 7.1 months (range: 2.1–69.1 months). ORR was 60% (95% CI, 29.6–90.3%) for the higher dose and 10.3% (95% CI, 0.7–19.8%) for the lower dose. Median time to progression for all patients was 2.7 months (95% CI, 1.7–3.8 months) and the median overall survival was 8.9 months (95% CI, 6.6–11.3 months). Grade 3/4 toxicities included neutropenia (90%), febrile neutropenia (50%), asthenia (40%), and diarrhea (10%) with the higher dose and neutropenia (71%), febrile neutropenia (11%), diarrhea (24%), and asthenia (24%) with the lower dose. There were two possible treatment-related deaths.

The combination of irinotecan and docetaxel, once every three weeks shows anti-tumor activity but is not feasible as a second-line treatment for AGC patients after failure of fluoropyrimidine- or platinum-based chemotherapy due to the high rate of toxicities.