ROLE OF RECOMBINANT INTERFERON ALFA-2A MAINTENANCE IN PATIENTS WITH LIMITED-STAGE SMALL-CELL LUNG-CANCER RESPONDING TO CONCURRENT CHEMORADIATION - A SOUTHWEST-ONCOLOGY-GROUP STUDY

Purpose: This study was designed to determine if recombinant interfero n alfa-2a (rIFN alpha-2a) could prolong remission duration and/or surv ival in patients with limited-stage small-cell long cancer (SCLC) who achieved an objective response to chemoradiotherapy. A secondary end p oint was to assess the toxicity of chronic IFN administration. Patient s and Methods: One hundred seventy-one of 215 eligible patients achiev ed an objective response and were eligible to receive rIFN alpha-2a (3 million units [MU]/m(2) subcutaneously three times per week escalated to 9 MU/m(2) as tolerated) or observation for 2 years. Results: One h undred thirty-two of 140 registered patients were eligible. Sixty-four patients were randomized to receive IFN and 68 to observation alone. The median time from randomization to progression wets 9 months on the IFN arm and 10 months on the observation arm (P = .72). The overall m edian survival time was 16 months on the observation arm versus 13 mon ths on the IFN arm (P = .77). Significant toxicities occurred in the r IFN alpha-2a arm. Grade 3 or higher toxicities included malaise, fatig ue, and/or lethargy (30%), leukopenia (14%), neutropenia (13%), dyspne a (13%), nausea (11%), and respiratory infection (6%). Forty-three pat ients discontinued treatment due to intolerable side effects. Conclusi on: rIFN alpha-2a in the dose and schedule used in this study failed t o prolong response duration or survival in patients with limited-stage SCLC who had previously responded to an induction chemoradiotherapy p rogram. Failure may have been partly related to poor tolerance and ina bility to complete therapy. (C) 1995 by American Society of Clinical O ncology.