Phase II study of weekly oxaliplatin and high-dose infusional 5-fluorouracil plus leucovorin in pretreated patients with metastatic colorectal cancer.

Background: Chemotherapy with oxaliplatin, fluorouracil (5-FU) and leucovorin (LV) has proven efficacy in patients with advanced colorectal carcinoma (CRC), although the optimal dosage and administration schedule are still unclear. This phase II trial investigated the tolerability and activity of weekly oxaliplatin, high-dose infusional 5-FU and LV in pretreated patients with metastatic CRC.
Materials and Methods: Patients received weekly courses of i.v. oxaliplatin 50 mg/m2 (1-h infusion), LV 100 mg/m2 (1-h infusion) and 5-FU 2100 mg/m2 (24-h infusion) until disease progression or unacceptable toxicity. NCI-CTC criteria were used for assessment of side-effects (at each cycle) and WHO criteria for assessment of tumour response (every 8 cycles). For descriptive purposes, time to progression, overall survival and duration of objective response were also calculated.
Results: Forty-four patients were enrolled and received a total of 606 cycles (median 13/patient, range 4-33), and 70% of courses (421/606) were delivered at 100% of the planned dose. The most frequent side-effects were gastrointestinal and neurological and incidence rates were: diarrhoea 66% (grade III: 29%), nausea/vomiting 54%, neurotoxicity 34% (grade III: 2%), fatigue 27%, mucositis 22%, leucopenia 14%. No grade IV toxicity was observed. Objective response rates were: partial response 23% (10 patients), stable disease 59% (26) and progressive disease 11% (5). Median time to progression was 7 months, overall survival 13 months and the duration of partial response and stable disease were 9 and 6 months, respectively.
Conclusion: The study demonstrated that this regimen has a favourable tolerability profile and is an active combination in the pretreated metastatic CRC patient, deserving further evaluation in phase III trials.