Abstract
We previously reported initial results in 102 multiple myeloma patients treated with sequential high-dose melphalan and autologous hematopoietic cell transplantation followed by 200 cGy total body irradiation with or without fludarabine 90 mg/m2 and allogeneic hematopoietic cell transplantation. Here we present long-term clinical outcomes among the 102 initial patients and among 142 additional patients, with a median follow-up of 8.3 (range 1.0-8.1) years. Donors included human leucocyte antigen identical siblings (n= 179) and HLA-matched unrelated donors (n= 65). A total of 209 patients (86%) received tandem autologous-allogeneic upfront, while thirty-five patients (14%) failed a previous autologous hematopoietic cell transplantation before the planned autologous-allogeneic transplantation. Thirty-one patients received maintenance treatment at a median of 86 days (range, 61-150) days after allogeneic transplantation. Five-year rates of overall survival and progression-free survival were 54% and 31%, respectively. Ten-year overall survival and progression-free survival were 41% and 19%, respectively. Overall non-relapse mortality was 2% at 100 days and 14% at 5 years. Patients with induction-refractory disease and those with high-risk biological features experienced shorter overall survival and progression-free survival. A total of 152 patients experienced disease relapse and 117 of those received salvage treatment. Eighty-three of the 117 patients achieved a clinical response, and for those, the median duration of survival after relapse was 7.8 years. Moreover, a subset of patients who became negative for minimal residual disease by flow cytometry experienced a significantly lower relapse rate as compared with minimal residual disease-positive patients (P = 0.03). Our study showed that the graft-vs-myeloma effect after non-myeloablative allografting allowed long-term disease control in standard and high-risk patient subsets. Ultra-high-risk patients did not appear to benefit from tandem autologous/allogeneic hematopoietic cell transplantation because of early disease relapse. Incorporation of newer anti-MM agents into the initial induction treatments before tandem hematopoietic cell transplantation and during maintenance might improve outcomes of ultra-high-risk patients. Clinical trials included in this study are registered with ClinicalTrials.gov and include NCT00075478, NCT00005799, NCT01251575, NCT00078858, NCT00105001, NCT00027820, NCT00089011, NCT00003196, NCT00006251, NCT00793572, NCT00054353, NCT00014235, NCT00003954, NCT00003954.
View details for PubMedID 30262560