Sequential chemoimmunotherapy of colorectal cancer: evaluation of methotrexate, Baker's Antifol and levamisole

Fifty-two untreated patients with colorectal cancer were randomized to receive 5-fluorouracil (5-FU) alternating either with methotrexate (MTX) or Baker's Antifol (BAF) with or without the immunostimulant, levamisole (Program I). Fifty-five patients who had received prior treatment were randomized to receive methyl-CCNU (Me) with MTX or BAF (Program II). Fifteen of these patients had failed to respond to initial therapy with 5-FU plus MTX or BAF and subsequently received Me plus the alternate antifol. Overall response rate for each of programs I and II was 10%. The responses were 1/11 with 5-FU-MTX plus levamisole, 2/12 with 5-FU-MTX, 1/8 with 5-FU-BAF plus levamisole, 0/8 with 5-FU-BAF, 2/20 with Me-MTX and 2/21 with Me-BAF. The median survival times (MST) for patients receiving Programs I and II were 10 and 5 months, respectively. The MST for all patients receiving MTX was significantly longer than that of patients receiving BAF Survival was not influenced by levamisole administration. Both chemotherapy programs were well tolerated. The sequential administration of 4 active agents failed to improve the results of treatment of colorectal cancer.