Trends in allogeneic stem cell transplantation for multiple myeloma: a CIBMTR analysis

Allogeneic hematopoietic cell transplantation in multiple myeloma is limited by prior reports of high treatment-related mortality. We analyzed outcomes after allogeneic hematopoietic cell transplantation for multiple myeloma in 1207 recipients in 3 cohorts based on the year of transplantation: 1989-1994 (n = 343), 1995-2000 (n = 376), and 2001-2005 (n = 488). The most recent cohort was significantly older (53% > 50 years) and had more recipients after prior autotransplantation. Use of unrelated donors, reduced-intensity conditioning and the blood cell grafts increased over time. Rates of acute graft-versus-host (GVHD) were similar, but chronic GVHD rates were highest in the most recent cohort. Overall survival (OS) at 1-year increased over time, reflecting a decrease in treatment-related mortality, but 5-year relapse rates increased from 39% (95% confidence interval [CI], 33%-44%) in 1989-1994 to 58% (95% CI, 51%-64%; P < .001) in the 2001-2005 cohort. Projected 5-year progression-free survival and OS are 14% (95% CI, 9%-20%) and 29% (95% CI, 23%-35%), respectively, in the latest cohort. Increasing age, longer interval from diagnosis to transplantation, and unrelated donor grafts adversely affected OS in multivariate analysis. Survival at 5 years for subjects with none, 1, 2, or 3 of these risk factors were 41% (range, 36%-47%), 32% (range, 27%-37%), 25% (range, 19%-31%), and 3% (range, 0%-11%), respectively (P < .0001).