Autologous stem cell transplantation for AL amyloidosis: a multicenter summary of outcomes 2010-2020

The role of autologous stem cell transplantation (ASCT) is central in AL amyloidosis and continues to be defined in the era of newer therapies. To evaluate contemporary patient selection, practice patterns, and outcomes, we conducted a retrospective, multicenter study across nine tertiary referral centers, including 1047 patients with AL amyloidosis who underwent ASCT between 2010 and 2020. Most patients (67.9%) received full-dose melphalan conditioning, and 66.5% received pre-ASCT induction therapy, predominantly proteasome inhibitor-based regimens. Day-100 all-cause mortality was 3.0%, representing a substantial improvement compared with historical cohorts. Post-ASCT hematological responses were satisfactory in 75.4% of patients. Among patients with paired assessments, ASCT deepened responses in 56.3% who had not achieved a complete response with induction therapy. With a median follow-up of 5.1 years, the median overall survival was 6.3 years. Independent predictors of inferior survival included age ≥60 years, bone marrow plasma cells ≥20%, pre-ASCT dFLC ≥40 mg/L, elevated cardiac biomarkers, lambda-restricted disease, reduced eGFR and reduced-dose conditioning. In this contemporary cohort, ASCT for AL amyloidosis demonstrated low early mortality, high rates of deep hematologic response, and durable survival in carefully selected patients. These findings support its role as an effective consolidative strategy, while its optimal positioning alongside emerging therapies requires further study.