Of 496 consecutive patients with multiple myeloma (MM) enrolled in clinical trials of tandem transplants with peripheral blood stem cells support, 470 (95%) completed the first autotransplant with melphalan 200 mg/m2 (MEL 200) and 363 (73%) completed the second transplant with either MEL 200 (40%), MEL 140 mg/m2 (MEL 140) with total-body irradiation (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 median interval from first to second transplant was 5 months. Treatment-related mortality during the first year after transplantation was 7%, and 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] < or = 2.5 mg/L) and C-reactive protein ([CRP] < or = 0.4 mg/dL) were the most significant standard parameters associated with both prolonged EFS and OS. Median OS exceeded 5.5 years in the one third of patients with both low B2M and CRP. When cytogenetics were included in the analysis, the presence of 11q abnormalities and/or complete or partial deletion of chromosome 13 (“unfavorable karyotype”) became a dominant negative feature for both EFS and OS. In addition to these pretransplant parameters, attainment of CR and application of two transplants within 6 months both significantly extended EFS and OS. The group of patients (7%) with high B2M and CRP with either IgA isotype or unfavorable karyotype had the worst prognosis (EFS, < or = 10 months; median OS, < or = 12 months) and will require novel therapy. We conclude that tandem transplants are feasible in the majority of patients up to age 70 years, effecting 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 transplant no more than 6 months later.

Summary:The role of more intense conditioning for second transplant was evaluated in myeloma patients achieving at least partial remission (PR) after first transplant with melphalan at 200 mg/m 2 . Forty-three patients received more intensive conditioning for the second transplant. Nineteen patients received cyclophosphamide 120 mg/kg along with melphalan 200 g/m 2 (MEL-CY; group 1) while 24 patients received total body irradiation (1125 cGy) in conjunction with melphalan 140 mg/m 2 (MEL-TBI; group 2). Forty-three matched control patients were identified from 450 patients receiving melphalan alone for second transplant (MEL200; group 3). Engraftment and toxicities were comparable among the groups with the exception of increased treatmentrelated mortality of 8% in group 2 compared to none in groups 1 and 3 (P = 0.07). Despite identical CR rates of 74, 71 and 70%, respectively, in groups 1, 2 and 3 (P = 1.0), event-free survival (median: 27, 15 and 61; P Ͻ 0.0001) and overall survival (median: 39, 25 and 76 months; P = 0.003) were significantly decreased in patients receiving more intensive conditioning (groups 1 and 2). Lymphocyte recovery, evaluated as a surrogate for immune recovery, was inferior in more intensively treated patients (groups 1 and 2 compared to group 3). Our findings suggest that more intense conditioning appears to have no benefit in patients responding to their first cycle of high-dose therapy and may even be detrimental in this setting. with tandem autotransplants in previously untreated patients. In a pair-mate analysis, this approach (termed 'Total Therapy') led to a significantly higher CR, overall survival (OS) and event-free survival (EFS), when compared to a matched cohort of patients treated with conventional-dose therapy on Southwest Oncology Group trials. 2 In these initial studies, patients who failed to achieve a partial remission (PR) after the first transplant (Tx-1), received high-dose melphalan plus total body irradiation (MEL-TBI) or cyclophosphamide (MEL-CY) as a conditioning regimen for the second autotransplant (Tx-2). Even in this primary unresponsive group of patients, a second high-dose cycle induced a CR in 10% and PR in 55%. Among patients achieving уPR after Tx-1, Tx-2 utilizing MEL-200 led to attainment of CR in 38%, resulting in an increase in the cumulative CR rate on an intent-totreat basis from 24 to 43%. With the hypothesis that the benefit of more dose-intense conditioning with MEL-TBI or MEL-CY may be even more effective in the patients responding to Tx-1, we applied these regimens to 43 patients achieving уPR after Tx-1. In this study, we have compared the outcome of patients attaining уPR after Tx-1 and receiving MEL 200 + cyclophosphamide for Tx-2 (group 1) or Mel 140 + TBI (group 2) with a matched group of patients receiving MEL 200 as conditioning for Tx-2 (group 3). Each group was evaluated for treatment response, survival, engraftment kinetics and toxicities. Patients and methodsForty-three myeloma patients achieving at least a PR after Tx-1 with MEL 20...

To improve the safety of autotransplantation for myeloma, peripheral blood stem cell (PBSC) collection was attempted in 75 previously treated patients after the administration of high-dose cyclophosphamide (HD-CTX; 6 g/m2) with or without granulocyte-macrophage colony- stimulating factor (GM-CSF). Sixty patients subsequently received melphalan 200 mg/m2 (57 patients) or melphalan 140 mg/m2 and total body irradiation (850 cGy) (3 patients) supported by both autologous bone marrow and PBSC; 38 patients received GM-CSF posttransplantation. Among 72 patients undergoing PBSC apheresis, “good” mobilization (greater than 50 colony-forming units granulocyte-macrophage [CFU-GM] per 10(5) mononuclear cells) was achieved when prior chemotherapy did not exceed 1 year and when GM-CSF was used post-HD-CTX; similarly, rapid platelet recovery to 50,000/microL within 2 weeks was associated with “good” PBSC mobilization. These same variables also predicted for rapid engraftment after autotransplantation, so that hematologic recovery (granulocytes greater than 500/microL and platelets greater than 50,000/microL) proceeded within 2 weeks among the 37 patients with “good” PBSC collection. As a result of rapid neutrophil recovery (greater than 500/microL) within a median of 2 weeks, infectious complications both post-HD-CTX and posttransplant were readily manageable, resulting in only one treatment-related death post-HD-CTX. The cumulative response rate (greater than or equal to 75% cytoreduction) for all 75 patients was 68%, with 12-month event-free and overall survival projections of about 85%. Using both bone marrow and PBSC together with GM-CSF, autotransplants are safe and appear effective in myeloma, especially when prior therapy had been limited to less than 1 year. More than 80% of transplanted patients achieved complete hematologic recovery within a median of 1 month posttransplant (granulocytes greater than 1,500/microL; platelets greater than 100,000/microL; hemoglobin greater than 10 g%), thus providing sufficient hematopoietic reserve for further chemotherapy in the event of posttransplant relapse.

Data from 225 multiple myeloma (MM) patients, undergoing peripheral stem cell (PBSC) mobilization with high-dose cyclophosphamide and hematopoietic growth factors, were analyzed for median CD34+ cell count and median time to post-transplant neutrophil (ANC > 500/microliters) and platelet (> 50,000/microliters) recovery according to age groups (20-49, 50-59 and > or = 60 years) and duration of prior therapy (< or = 12, 13-24, or > 24 months). Fifty-seven of the 225 patients were > or = 60 years. No difference in either the median number of CD34+ cells collected or time to engraftment occurred between age groups, when adjusted for duration of prior therapy. These data support the concept that autotransplants can be performed safely in patients > or = 60 years and that these patients should not be excluded from the most effective treatment modalities.

One hundred and thirty-five patients with advanced and refractory myeloma received one of three high-dose therapy regimens: melphalan at doses of 90 to 100 mg/m2 (MEL 100; 47 patients) without autotransplant; total body irradiation (TBI; 850 cGy) with either melphalan 140 mg/m2 or thiotepa 750 mg/m2 and autologous bone marrow transplant (ABMT) (< or = 30% plasma cells; 21 patients); melphalan 200 mg/m2 (MEL 200) supported by both peripheral blood stem cells (PBSC) and ABMT plus GM- CSF intended as a double-transplant program (67 patients; 42 have completed and 3 are still awaiting a second autotransplant; 5 additional patients received an allograft for their second transplant). Mortality within 2 months of therapy was 20% to 25% with MEL 100 and TBI regimens, but less than 1% with MEL 200, mainly because severe neutropenia (< 500/microL) was shortened to less than 1 week due to infusion of PBSC and use of growth factor therapy. Low beta 2- microglobulin (beta 2M) levels < or = 2.5 mg/L and MEL 200 therapy were identified as the two most important independent favorable variables associated with prolonged event-free survival (EFS) and overall survival (OS). On the basis of these two parameters, three risk groups were defined: 29 good-risk patients with low beta 2M receiving MEL 200 had the best outcome, with median durations of EFS of 37 months and projected OS of > or = 43 months; 54 intermediate-risk patients displaying one of the two favorable parameters had EFS and OS durations of 16 and 36 months, respectively; and 52 poor-risk patients with high beta 2M not receiving MEL 200 had a dismal prognosis, with EFS of 3 months and OS of 5 months (all P > .0001). Further analysis that excluded treatment as a variable identified high beta 2M and resistant relapse as the two major adverse prognostic factors, one of which was present in 80% of the 135 patients. Among these 108 high-risk patients, prognosis was improved markedly with MEL 200 because of both better supportive care (PBSC and hematopoietic growth factors) and more intensive therapy using the double-transplant approach. This study supports the concept that safer and potentially more-effective therapies can be developed in the setting of advanced and resistant disease.