Phase II trial of 5-fluorouracil and the natural l isomer of folinic acid in the treatment of advanced colorectal carcinoma.

Between February 1991 and July 1992, 79 previously untreated patients with metastatic colorectal carcinoma were enrolled in a phase II study of combined 5-fluorouracil (5-FU) and l-folinic acid (FA). 5-FU 370 mg/m2/day was administered for 5 consecutive days as an intravenous (i.v.) bolus injection preceded by l-FA 100 mg/m2/day with the same administration modality. Treatment was given every 4 weeks until progression. 79 patients were evaluable for toxicity and 64 for response. 2 patients (3\%) achieved a complete remission and 8 (12.5\%) a partial remission, 33 (52\%) had stable disease and 21 patients (33\%) had progressive disease. Median duration of remission was 32.5 weeks and median survival for all evaluable patients was 64.5 weeks. Substantial to severe side-effects occurred in 39\% of patients. Dose-limiting toxicity (grade 3-4) was mainly diarrhoea (18\%) and mucositis (15\%). Nausea/vomiting, cutaneous toxicity, leucopenia, alopecia and conjunctivitis of grade 3-4 occurred respectively in 6, 4, 2.5, 1 and 1\% of cases. Toxicity appeared to be substantially similar to that characteristic of combined 5-FU and the chiral mixture of d,l-FA. Efficacy was within the range of that observed with the 5-FU/d,l-FA combination, although at the lower level.