A PHASE-II TRIAL OF INTERLEUKIN-2 AND INTERFERON-ALPHA IN THE TREATMENT OF METASTATIC COLORECTAL-CARCINOMA

A total of 29 patients with stage IV colorectal cancer were entered in to a phase II trial of bolus interleukin-2 (IL-2) and interferon-alpha (IFN alpha) (3 x 10(6) U/m(2) of each cytokine given i.v. q8h x 15 do ses and repeated in 2 weeks). Immunologic parameters measured on isola ted peripheral blood lymphocytes revealed increased activated T cells with upregulated natural killer and lymphokine-activated killer activi ty. Among 24 evaluable patients, there were 4 partial responses (17%) of short duration (less than or equal to 6 months). Three of the respo nding patients had been refractory to prior chemotherapy. Overall medi an survival in the 24 evaluable patients was 18.5 months. Therapy nece ssitated an inpatient setting, with the most common toxicities being h ypotension, hepatic insufficiency, fever, hypocalcemia, nausea/vomitin g, and renal insufficiency. There were two treatment-related deaths. B ecause neither IL-2 nor IFN alpha alone has significant activity again st colorectal cancer, the responses observed in this study suggest a p otential synergistic effect between the two cytokines. However, the to xicity and short duration of response without survival benefit do not support the routine use of this regimen as a therapeutic modality for this tumor histology.