AUTOTRANSPLANTS IN MULTIPLE-MYELOMA - WHAT HAVE WE LEARNED

Of 496 consecutive patients with multiple myeloma (MM) enrolled in cli nical trials of tandem transplants with peripheral blood stem cells su pport, 470 (95%) completed the first autotransplant with melphalan 200 mg/m(2) (MEL 200) and 363 (73%) completed the second transplant with either MEL 200 (40%), MEL 140 mg/m(2) (MEL 140) with total-body irradi ation (17%), or a combination of alkylating agents (16%), depending on the response status prior to the second transplant; 31 patients up to age 60 years received an allograft as the second transplant. The medi an interval from first to second transplant was 5 months, Treatment-re lated mortality during the first year after transplantation was 7%, an d complete remission (CR) was obtained in 36%; the median durations of event-free survival (EFS) and overall survival (OS) after transplant were 26 and 41 months, respectively. Low beta(2)-microglobulin ([B2M] less than or equal to 2.5 mg/L) and C-reactive protein ([CRP] less tha n or equal to 0.4 mg/dL) were the most significant standard parameters associated with both prolonged EFS and OS. Median OS exceeded 5.5 yea rs in the one third of patients with both low B2M and CRP. When cytoge netics were included in the analysis, the presence of 11q abnormalitie s and/or complete or partial deletion of chromosome 13 (''unfavorable karyotype'') became a dominant negative feature for both EFS and OS. I n addition to these pretransplant parameters, attainment of CR and app lication of two transplants within 6 months both significantly extende d EFS and OS. The group of patients (7%) with high B2M and CRP with ei ther IgA isotype or unfavorable karyotype had the worst prognosis (EFS , less than or equal to 10 months; median OS, less than or equal to 12 months) and will require novel therapy. We conclude that tandem trans plants are feasible in the majority of patients up to age 70 years, ef fecting CR in one third of all patients. Median OS was greater than 5. 5 years, regardless of pretransplant features, if the first transplant was applied within 12 months of initial treatment and the second tran splant no more than 6 months later. (C) 1996 by The American Society o f Hematology.