2 DOSAGE INTERFERON-ALPHA-2B MAINTENANCE THERAPY IN PATIENTS AFFECTEDBY LOW-RISK MULTIPLE-MYELOMA IN PLATEAU-PHASE - A RANDOMIZED TRIAL

Background and Objective. The role of interferon (IFN) in the remissio n phase of multiple myeloma (MM) is still an open question, particular ly for its scheduling and the subset of patients who could benefit fro m this approach. The present randomized multicenter study was designed to compare two schedules of IFN maintenance therapy in order to asses s the difference in effectiveness and tolerance. Design and Methods. T his prospective randomized multicenter study was attempted to assess t he best schedule of IFN administration in the maintenance treatment of MM in plateau phase with regard to progression free survival (PFS) an d toxicity. The second aim was defining the difference between the two schedules in overall survival (OS) and identifying the critical dose of IFN therapy needed to prolong plateau phase and survival. We enroll ed 52 patients affected with low-risk MM (i.e. with serum beta 2-micro globulin < 6.0 mg/L and serum albumin > 3.0 g/dL); 27 patients (group A) were randomly assigned to receive IFN alpha-2b 3 megaunits (MU) sub cutaneously three times a week and 25 patients (group B) 3 MU/day unt il disease progression. Results. Median progression free survival (PFS ) was 11.9 months in group A and 38.3 months in group B (p= 0.0038). M edian survival was 63.2 months in group A and 61.9 months in group B ( p= 0.489). However, those patients who were given an IFN dose greater than or equal to 30 MU/month experienced a significantly longer PFS an d survival than the other patients. Seventeen patients (32.7%) discont inued therapy and sixteen patients (30.8%) reduced IFN alpha-2b dose b ecause of severe side effects without having a significant difference between the two schedules. Interpretation and Conclusions. Our results show that patients treated with IFN alpha 3 MU/day had a significantl y longer remission duration than patients treated with IFN alpha( 3 MU three times weekly. Moreover, an IFN dose is probably critical for ob taining a longer survival in patients affected with low-risk MM. Since the patients' discomfort during a IFN maintenance therapy was frequen tly experienced the quality of their lives should be carefully taken i nto account.