Phase I trial of combined recombinant interleukin-2 with levamisole in patients with advanced malignant disease

A Phase I study of rIL-2 and levamisole was performed to evaluate the activity, toxicity, and effect on immune parameters of this combination of agents in patients with advanced malignancy. Twelve patients with advanced cancer were included and begun on therapy with rIL-2, 1 x 10⁶ U/m² subcutaneously (SQ) daily for 5 days and levamisole beginning at 25 mg/m² orally three times daily for 5 days. The dose of levamisole was increased to 50 mg/m² thrice daily during this study. Immune parameter analysis included the percentages of lymphocyte subsets in peripheral blood, cellular cytotoxicity assays versus K562 and Daudi cells, and lymphocyte blastogenesis to the recall antigens tetanus toxoid and Candida albicans. The dose-limiting toxicities were pruritus, nausea, and facial edema. There were no indications of significant hematologic or hepatorenal toxicities. No patient fulfilled the traditional criteria for an objective response. In 8 of 9 patients with immune parameter data available there was an increase in cellular cytotoxicity and in the percentage of lymphocytes with the natural killer phenotype (CD3-, CD16/56+). This regimen can be given as an outpatient with acceptable toxicity. For Phase II investigations the doses of rIL-2, 1 x 10⁶ U/m² SQ daily x 5 days and levamisole, 50 mg/m² three times daily x 5 days is recommended.