Randomized trial of alpha-interferon or dexamethasone as maintenance treatment for multiple myeloma

In order to assess the role of alpha-interferon or dexamethasone as mainten ance therapy for multiple myeloma, 172 consecutive, previously untreated pa tients with disease of low or intermediate tumor mass received primary ther apy with oral melphalan and intermittent, high-dose dexamethasone (MD), rep eated monthly. Within 5 months, 84 responding patients were assigned at ran dom to maintenance treatment with alpha-interferon (3 mU s.c. 3 x weekly) o r dexamethasone (20 mg/m(2) p.o. each morning for 4 days) repeated monthly until relapse. Upon relapse, Mn was resumed for 2 cycles and second respons es were maintained with 4-day courses of melphalan-dexamethasone until seco nd relapse. Initial response was achieved in 88 patients (51%) after a medi an 0.7 month and no more than 3 courses of Mn, a frequency of response simi lar to that observed previously with dexamethasone alone. There were Identi cal median remissions of 10 months with interferon or dexamethasone, both m aintenance regimens being associated with infrequent, mild, and reversible side effects. Significantly more patients responded again to resumption of Mn after disease relapse to interferon (82%) than to dexamethasone (44%) (P = 0.001). The median remission from randomization to melphalan-resistant s econd relapse was 32 months for patients maintained initially on interferon compared to 19 months for those on dexamethasone (P = 0.01). These finding s supported an advantage for interferon in remission maintenance by increas ing the frequency of tumor recontrol with later treatment that included dex amethasone. (C) 2000 Wiley-Liss, Inc.