High-dose interleukin-2 therapy for metastatic renal cell carcinoma: A contemporary experience.

Abstract

e15604 Background: Despite recent advances in targeted treatment options, high dose interleukin-2 (HDIL-2) remains an important therapeutic option for metastatic renal cell carcinoma (mRCC). We present a contemporary experience of HDIL-2 in a high-volume, National Cancer Institute (NCI)-designated cancer center. Methods: Patients with mRCC who received HDIL-2 monotherapy as a first- or second-line therapy during 2004-2011 were identified. Patients’ demographics, pathologic variables, renal function, time until start of HDIL-2 therapy, number of cycles given (1-3), best responses (complete response; CR, partial response; PR, stable disease; SD, and progressive disease; PD), and primary RCC treatment were analyzed. Progression free survival (PFS) and overall survival (OS) were determined. Results: Of 176 mRCC patients, 91 patients were treated with HDIL-2 (59 as a primary treatment). Median age was 51 years and 73.9% were males. Median Follow-up was 44.9 months. Majority (92%) of tumors showed clear cell histology, and 14.8% had impaired renal function (creatinine >1.5 mg/dL) prior to treatment. Patients with impaired initial renal function were more likely to get more treatment cycles (2-3) than those with adequate initial kidney function (92.3% vs.50.6%, respectively; p=0.002). Eighteen (20.5%) patients underwent cytoreductive nephrectomy. Lower tumor stage at diagnosis correlated with better treatment response (p=0.023), but with longer time from diagnosis to initiation of HDIL-2 (p=0.011). Prominent therapy complications included hypotension (67.4%), renal impairment (63%), impaired liver function (42.4%), and thrombocytopenia (31.5%). None needed hemodialysis for IL-2 induced renal toxicity, and all regained their pre-treatment baseline kidney functions after therapy. Four patients (4.5%) had CR, 11.4% had PR, and 31.8% had SD. Median PFS and OS were 8.6 and 35.5 months, respectively. Estimated 2-year OS rate was 60.6%. Conclusions: Incorporating HDIL-2 therapy in treatment strategies of patients with mRCC added to the patients’ survival in this contemporary series. HDIL-2 therapy appears to be well tolerated in patients with preexisting renal impairment with no long term renal toxicity.