Sustained Oral Indomethacin and Ranitidine with Intermittent Continuous Infusion Interleukin-2 in Advanced Renal Cell Carcinoma

Abstract

Experimental work in murine models has shown that, during the development of tumors, prostaglandin E2 produced by host macrophages inactivates natural killer cells and suppresses lymphokine-activated killer (LAK) cell development. Chronic indomethacin therapy when combined with interleukin-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 patients with advanced renal cell carcinoma. Patients were placed on indomethacin and ranitidine orally at least one week prior to commencing therapy with IL-2. IL-2 was given by continuous infusion for three courses, each consisting of 5 days of treatment with 6 days of rest. Initial dose of IL-2 was 18.0 x 10(6) IU/m2/day for the first course with escalation 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 admitted to a general oncology ward for therapy with IL-2, and vasopressor agents were not used. Thirty-two patients were eligible, with 7 patients withdrawing early from the study. Twenty-five patients went on to receive at least one course of IL-2. Two complete and three partial responses were seen for an objective response rate of 5/25 (20%) for eligible and treated patients or 5/32 (16%) for all patients entered onto the study, regardless of treatment status. The response rate to this regimen is comparable with other high dose IL-2 regimens in renal cell carcinoma, including those employing adoptive therapy with lymphokine-activated killer cells.