SUSTAINED ORAL INDOMETHACIN AND RANITIDINE WITH INTERMITTENT CONTINUOUS-INFUSION INTERLEUKIN-2 IN ADVANCED RENAL-CELL CARCINOMA

Experimental work in murine models has shown that, during the developm ent of tumors, prostaglandin E2 produced by host macrophages inactivat es natural killer cells and suppresses lymphokine-activated killer (LA K) cell development. Chronic indomethacin therapy when combined with i nterleukin-2 (IL-2) can totally eradicate experimental lung metastases in these models. A phase II trial was performed to study the clinical efficacy of chronic indomethacin and intermittent IL-2 therapy in pat ients with advanced renal cell carcinoma. Patients were placed on indo methacin and ranitidine orally at least one week prior to commencing t herapy with IL-2. IL-2 was given by continuous infusion for three cour ses, each consisting of 5 days of treatment with 6 days of rest. Initi al dose of IL-2 was 18.0 x 10(6) IU/m2/day for the first course with e scalation to 27.0 x 10(6) IU/m2/day for the second and 36.0 x 10(6) IU /m2/day for the third course, if toxicity allowed Patients were admitt ed to a general oncology ward for therapy with IL-2, and vasopressor a gents were not used Thirty-two patients were eligible, with 7 patients withdrawing early from the study. Twenty-five patients went on to rec eive at least one course of IL-2. Two complete and three partial respo nses were seen for an objective response rate of 5/25 (20%) for eligib le and treated patients or 5/32 (16%) for all patients entered onto th e study, regardless of treatment status. The response rate to this reg imen is comparable with other high dose IL-2 regimens in renal cell ca rcinoma, including those employing adoptive therapy with lymphokine-ac tivated killer cells.