Maintenance therapy with interferon-alpha (IFN-alpha) versus IFN-alpha plus chemotherapy in multiple myeloma (MM). The Greek Myeloma Study Group.

Results of studies using IFN-alpha treatment for maintaining remission and prolonging survival in multiple myeloma (MM) are in conflict and trials seeking optimum use for this biological response modifier are continuing. Between 1989 and 1993 a prospective randomized multicentre trial was undertaken to evaluate the role of the combination of IFN-alpha with chemotherapy (CT) in maintenance treatment of MM. For remission induction, in patients 65 yr or younger, we used VAD (group A) and for the remaining Melphalan and Prednisone (MP) (group B). For maintenance, patients were randomized to receive IFN-alpha 3 x 10(6) i.u. s.c. t.i.w. (group I) or alternating monthly cycles of IFN-alpha and CT. The CT cycles were also alternated (VAD, MP, CP) in an effort to prevent the development of multidrug resistance. Median survival of the two maintenance groups from randomization (36 months for group I and 31 months for group II, p = 0.3) as well as response duration (13 months in group I and 15 months in group II, p = 0.95) were similar. Toxicities were more pronounced both with VAD induction and in the combination maintenance arm. The addition of chemotherapy to the IFN maintenance regimen in MM did not have an advantage over IFN alone.