Trends and outcomes in allogeneic hematopoietic stem cell transplant for multiple myeloma at Mayo Clinic

Background Allogeneic transplant in myeloma remains controversial. Patients and Methods We performed a retrospective review of 76 patients in the Mayo Clinic database from 1993 to 2013 who underwent allogeneic hematopoietic stem cell transplant (HSCT) for myeloma. Results After excluding ineligible patients, among the remaining 66 patients, median age at transplant was 42 years and 87% had residual disease at the time of transplant. Myeloablative (71%) versus reduced intensity conditioning (29%), matched sibling donors (70%) versus unrelated donors showed no outcome difference. Median overall survival from the time of diagnosis and transplant were 75 and 24 months, respectively. Median time to disease progression (TTP) was 15 months and treatment-related mortality was 20% at day 100. Acute and chronic graft versus host disease (cGVHD) developed in 61% and 48% patients, respectively. In univariate analysis of overall survival (OS), factors predicting adverse outcome were pretransplant 24-hour total urinary protein (P =.035), peripheral blood versus bone marrow (OS 18 vs. 41 months; P =.02), number of previous therapies (P =.014), time from autologous to allogeneic HSCT (P =.019), and cGVHD (P =.01). TTP was adversely affected by number of previous regimens (P =.036) and PB as graft source (P =.016). In multivariate analysis for progression-free survival, number of previous regimens (P =.04), and for OS, time between autologous and allogeneic HSCT was significant (P =.009). Conclusion In 162 matched control subjects who were human leukocytoe antigen-typed, there were no survivors at 12 years compared with 20% in the group who received a transplant. In a second control group with 197 second autologous transplants, 10-year OS was 8%.