Recombinant alfa interferon in renal cell carcinoma: a randomized trial of two routes of administration

Ninety-seven patients with recurrent or metastatic renal cell carcinoma were randomized to receive recombinant interferon (IFN) alfa-2b (Intron A; Schering-Plough, Kenilworth, NJ) by either the subcutaneous (SC) or intravenous (IV) route. The SC dosage was 2 X 10(6) IU/m2 three times weekly, and the IV dose 30 X 10(6) IU/m2 for five consecutive days every 3 weeks. Dose escalation to a maximum of 10 X 10(6) IU/m2 SC and 50 X 10(6) IU/m2 IV was allowed for patients with minimal or absent toxicity. Five of 51 of the SC-treated patients (10%) and three of 46 of the IV-treated patients (7%) had a partial response (PR) or complete response (CR). Patients with prior nephrectomy, no prior treatment, and lack of bone metastases were most likely to respond, and a retrospective analysis of this subgroup revealed a 23% response rate. Achievement of response took from 3 weeks to 11 months, while response duration lasted from 3 to 31+ months. All responders had prior nephrectomy; six of eight had no prior chemotherapy or hormonal therapy; five had lung metastases, and none had bone metastases. Regardless of route, almost all patients developed a flu-like syndrome; however, grade 3 or greater toxicity was much more common for IV-treated patients. This trial demonstrates modest, but definite antitumor activity for recombinant interferon in advanced renal cell carcinoma. SC administration with lower dose and toxicity is as effective as treatment administered IV.