A phase I/II study of GLIF combination chemotherapy for taxane/platinum-refractory/resistant endometrial cancer (GOGO-EM2).

ABSTRACT

PURPOSE: Development of new treatment strategies for endometrial cancer that has become refractory or resistant to taxane/platinum is a critical need. The present study was a phase I/II study of gemcitabine, levofolinate, irinotecan, and 5-fluorouracil (5-FU) (GLIF) combination chemotherapy to determine optimal dosages, safety, and efficacy. METHODS: Taxane/platinum-resistant or -refractory endometrial disease was defined as tumor progression within 6 months after a taxane/platinum-based regimen. Maximum tolerated dose was investigated by a 3 + 3-designed phase I study. The phase II study was conducted using the recommended doses determined in the phase I study. RESULTS: The dosages recommended for the phase II trial were determined, in the phase I trial, to be gemcitabine 800 mg/m2, levofolinate 100 mg/m2, irinotecan 80 mg/m2, and 5-FU 1000 mg/m2. Thirty patients were enrolled, including the three patients who received GLIF therapy at the same dose as the recommended phase II dose in the phase I study. Two patients were excluded at this point due to study protocol violations, and the remaining 28 patients were included for analysis. Phase II revealed that the response and disease control rates were 7.1% (2/28) and 39.3% (11/28), respectively, and that the median PFS and OS were 3 months [95% confidence interval (CI) 3-7] and 12 months (95% CI 9-17), respectively. Febrile or grade 4 neutropenia was observed in 14% (4/28) of the cases. Grade 3 or 4 thrombocytopenia was not observed. CONCLUSION: We found that GLIF combination chemotherapy is potentially a useful treatment option for endometrial cancers refractory or resistant to taxane/platinum-based chemotherapy.