Intrahepatic interleukin-2 with chemotherapy for unresectable liver metastases: a randomized multicenter trial.

BACKGROUND/AIMS: A pilot study of Interleukin-2 (IL-2) with chemotherapy for unresectable colorectal liver metastases revealed a favorable response rate (76%). This prospective, randomized, multicenter study was conducted to evaluate the efficacy of this treatment protocol.

METHODOLOGY

Over a period of 32 months, 46 patients with unresectable liver metastases were randomly assigned to 1 of 3 treatment groups: group A: chemotherapy alone, group B: chemotherapy plus high-dose, intermittent IL-2 (2.1 x 10(6) U twice weekly) or group C: chemotherapy plus low-dose, continuous IL-2 (7 x 10(5) U daily). Treatment continued for 4 weeks in the hospital and on an outpatient basis according to the clinical response. No crossover between treatment arms was permitted.

RESULTS

IL-2 combined with chemotherapy produced a higher complete and partial response rate of 40% in group A, 60% in group B, and 78% in group C. Toxicity related to IL-2 included fever, chills, malaise, and eosinophilia.

CONCLUSIONS

Hepatic arterial infusion of chemotherapy plus IL-2 resulted in an increased tumor response when compared with chemotherapy alone. To confirm the efficacy of this treatment protocol, we have started a large-scale, randomized, multi-institution trial.