[A late phase II study of raltitrexed (ZD 1694) in chemotherapy-naive patients with advanced colorectal cancer].

A multicenter co-operative late phase II study of raltitrexed (ZD1694), a specific thymidylate synthase (TS) inhibitor, was conducted in chemotherapy-naive patients with advanced colorectal cancer. Raltitrexed was infused intravenously over 15 minutes once every three weeks. Between April 1996 and September 1998, 61 patients were enrolled and 58 were eligible. Fourteen patients experienced a partial response (PR), 22 no change (NC), 20 progressive disease (PD) and 2 no evaluable (NE). The overall response rate was 24.1% (95% CI: 13.9-37.2%). Responses were seen in lung (22.7%), liver (22.9%) and deep lymph nodes (10.0%). Median survival was 11.6 months. Grade 3 or 4 toxicities were: leukopenia (13.8%), neutropenia (24.1%), hemoglobin decrease (15.5%), FBC decrease (6.9%), hematocrit decrease (6.9%), thrombocytopenia (6.9%), transient SGPT increase (6.9%), nausea/vomiting (20.7%), anorexia (15.5%), and asthenia (6.9%). These adverse reactions were considered to be manageable. Only one death was associated with drug treatment. These results suggest that raltitrexed provides an effective and convenient treatment for patients with advanced and previously untreated colorectal cancer.