Raltitrexed plus oxaliplatin (TOMOX) as first-line chemotherapy for metastatic colorectal cancer. A phase II study of the Italian Group for the Study of Gastrointestinal Tract Carcinomas (GISCAD).

BACKGROUND To evaluate the safety and efficacy of the novel raltitrexed/oxaliplatin combination (TOMOX) as first-line chemotherapy for patients with advanced colorectal cancer. MATERIALS AND METHODS Previously untreated patients with metastatic colorectal cancer received raltitrexed 3 mg/m2 plus oxaliplatin 100 mg/m2, both intravenously, on day 1 every 3 weeks. Patients were re-evaluated after every third cycle and chemotherapy was continued up to tolerance or disease progression. RESULTS Fifty-eight patients from 13 Italian Group for the Study of Gastrointestinal Tract Carcinomas (GISCAD) centers were accrued from September 1999 to November 2000. According to the intention-to-treat analysis from 58 patients, the overall response rate was 50% [95% confidence interval (CI) 38% to 62%], with three complete responses and 26 partial responses. The median overall survival (44 patients currently alive) was >9 months and the median time to disease progression was 6.5 months (range 1-15 months). The main hematological toxicity was grade III/IV neutropenia, which occurred in 17% of patients, while anemia and thrombocytopenia were uncommon. Grade III/IV non-hematological toxicities were transient transaminitis (17% of patients); asthenia (16% of patients); neurotoxicity (10% of patients) and diarrhea (7% of patients). No toxic death was observed, one patient with grade IV asthenia after the first cycle refused chemotherapy. CONCLUSIONS The results of this study suggest that the TOMOX combination is an effective and well tolerated regimen for the treatment of advanced colorectal cancer. Its ease of administration and patient tolerance warrant further investigation as an alternative to fluoropyrimidine-based regimens with repeated and prolonged fluorouracil infusions.