Stem Cell Transplantation for Light Chain Amyloidosis: Decreased Early Mortality Over Time

Abstract

Purpose Autologous stem-cell transplantation (ASCT) has been used in patients with immunoglobulin light chain (AL) amyloidosis for more than two decades. Early experience raised concerns regarding safety with high early-mortality rates. Patients and Methods We report 20 years of experience with ASCT for AL amyloidosis at the Mayo Clinic Rochester. In all, 672 consecutive patients receiving ASCT for AL amyloidosis were divided into three cohorts on the basis of date of transplantation (cohort 1, 1996-2002 [n = 124]; cohort 2, 2003-2009 [n = 302]; and cohort 3, 2010-2016 [n = 246]). Results The median age for the entire cohort was 59 years, with patients in cohort 3 being slightly older than those in the other two cohorts (60 v 58 v 54 years for cohorts 3, 2, and 1, respectively; P < .001). Fewer patients in cohort 3 had more than two organs involved (9% v 18% v 19% for cohorts 3, 2, and 1, respectively; P < .001). More patients received pretransplantation therapy in cohort 3 compared with earlier time periods (49% v 38% v 42% for cohorts 3, 2, and 1, respectively; P = .02). Hematologic response was higher in cohort 3 (84% v 79% v 69% for cohorts 3, 2, and 1, respectively; P = .002). Median overall survival for the entire cohort was 122 months and improved over time (not reached v 120 months v 75 months for cohorts 3, 2, and 1, respectively; P < .001). Treatment-related mortality declined over time (2.4% v 8.6% v 14.5% for cohorts 3, 2, and 1, respectively; P < .001). On multivariable analysis, conditioning dose, Mayo stage 2012, and hematologic response were independent predictors of survival. Conclusion ASCT is a highly effective therapy for AL amyloidosis. The improved survival and markedly reduced treatment-related mortality in eligible patients indicate that this will remain an important first-line option even in the era of treatment approaches that use novel agents.