A randomized phase II study of biweekly irinotecan monotherapy or a combination of irinotecan plus 5-fluorouracil/leucovorin (mFOLFIRI) in patients with metastatic gastric adenocarcinoma refractory to or progressive after first-line chemotherapy.

BACKGROUND: The aim of this study was to evaluate the efficacy of irinotecan (CPT-11) monotherapy and CPT-11 plus 5-fluorouracil (5-FU)/leucovorin (LV) combination (mFOLFIRI) as second-line treatment in patients with advanced gastric cancer (AGC).

METHODS: A total of 59 patients were randomly assigned to either CPT-11 (150 mg/m(2) iv on day 1) or mFOLFIRI (CPT-11 150 mg/m(2) plus LV 20 mg/m(2) on day 1 followed by 5-FU 2,000 mg/m(2) over 48 h), every 2 weeks. The primary end point was objective response rate (ORR).

RESULTS: Following random assignment, 29 patients received CPT-11 and 30 patients mFOLFIRI. The ORR was 17.2 % [95 % confidence interval (CI) 3.4-30.9] and 20.0 % (95 % CI 5.6-34.3) for the CPT-11 and mFOLFIRI arms, respectively (P = 0.525). There was no significant difference in median progression-free survival: 2.2 months (95 % CI 0.2-4.3) for CPT-11 versus 3.0 months (95 % CI 2.0-3.7) for mFOLFIRI (P = 0.481) or in median overall survival: 5.8 months (95 % CI 3.0-8.7), compared with 6.7 months (95 % CI 5.3-8.2) (P = 0.514). Grade 3/4 toxicity was observed in 21 and 28 events in the CPT-11 and mFOLFIRI arms, respectively.

CONCLUSIONS: Although this study had a small sample size and limited statistical power, CPT-11 monotherapy and mFOLFIRI appear to be equally active and tolerable as second-line chemotherapy for AGC. The addition of 5-FU/LV to CPT-11 did not significantly improve efficacy.