Busulfan 12 mg/kg plus melphalan 140 mg/m2 versus melphalan 200 mg/m2 as conditioning regimens for autologous transplantation in newly diagnosed multiple myeloma patients included in the PETHEMA/GEM2000 study.

BACKGROUND: The aim of this study was to compare the long-term safety and efficacy of oral busulfan 12 mg/kg plus melphalan 140 mg/m(2) and melphalan 200 mg/m(2) as conditioning regimens for autologous stem cell transplantation in newly diagnosed patients with multiple myeloma in the GEM2000 study. DESIGN AND METHODS: The first 225 patients received oral busulfan 12 mg/kg plus melphalan 140 mg/m(2); because of a high frequency of veno-occlusive disease, the protocol was amended and a further 542 patients received melphalan 200 mg/m(2). RESULTS: Engraftment and hospitalization times were similar in both groups. Oral busulfan 12 mg/kg plus melphalan 140 mg/m(2) resulted in higher transplant-related mortality (8.4% versus 3.5%; P=0.002) due to the increased frequency of veno-occlusive disease in this group. Response rates were similar in both arms. With respective median follow-ups of 72 and 47 months, the median progression-free survival was significantly longer with busulfan plus melphalan (41 versus 31 months; P=0.009), although survival was similar to that in the melphalan 200 mg/m(2) group. However, access to novel agents as salvage therapy after relapse/progression was significantly lower for patients receiving busulfan plus melphalan (43%) than for those receiving melphalan 200 mg/m(2) (58%; P=0.01). CONCLUSIONS: Conditioning with oral busulfan 12 mg/kg plus melphalan 140 mg/m(2) was associated with longer progression-free survival but equivalent survival to that achieved with melphalan 200 mg/m(2) but this should be counterbalanced against the higher frequency of veno-occlusive disease-related deaths. This latter fact together with the limited access to novel salvage therapies in patients conditioned with oral busulfan 12 mg/kg plus melphalan 140 mg/m(2) may explain the absence of a survival difference. Oral busulfan was used in the present study; use of the intravenous formulation may reduce toxicity and result in greater efficacy, and warrants further investigation in myeloma patients. (Clinicaltrials.gov identifier: NCT00560053).

Influence of pre- and post-transplantation responses on outcome of patients with multiple myeloma: sequential improvement of response and achievement of complete response are associated with longer survival.

PURPOSE: Complete response (CR) is considered an important goal in most hematologic malignancies. However, in multiple myeloma (MM), there is no consensus regarding whether immunofixation (IF)-negative CR, IF-positive near-CR (nCR), and partial response (PR) are associated with different survivals. We evaluated the prognostic influence on event-free survival (EFS) and overall survival (OS) of these responses pre- and post-transplantation in newly diagnosed patients with MM. PATIENTS AND METHODS: We analyzed 632 patients from the prospective Grupo Español de Mieloma 2000 protocol who were uniformly treated with vincristine, carmustine, cyclophosphamide, melphalan, and predisone/vincristine, carmustine, adryamcine, and dexamethasone induction followed by high-dose therapy and autologous stem-cell transplantation. RESULTS: Post-transplantation response markedly influenced outcomes. Patients achieving CR had significantly longer EFS (median, 61 v 40 months; P < 10(-5)) and OS (medians not reached; P = .01) versus patients achieving nCR, who likewise had somewhat better outcomes compared with patients achieving PR (median EFS, 34 months, P = .07 v nCR; median OS, 61 months, P = .04). EFS and OS and influence of response were similar among older (age 65 to 70 years) and younger (age < 65 years) patients. Similar findings were observed with pretransplantation response, with trends toward EFS (P = .1; P = .05) and OS (P = .1; P = .07) benefit in patients achieving CR versus nCR and PR, respectively. Post-transplantation response was markedly influenced by pretransplantation response; improvements in response were associated with prolonged survival. CONCLUSION: Quality of response post-transplantation, notably CR, is significantly associated with EFS and OS prolongation in newly diagnosed patients with MM. There were trends toward similar associations with pretransplantation response status.