P-296: Autologous Stem Cell Transplantation for Light Chain Amyloidosis: A Single Center Report

Introduction: Since the 1990s, high-dose intravenous melphalan followed by autologous hematopoietic stem cell transplantation (ASCT) has been a cornerstone in treating light chain (AL) amyloidosis. Patients who achieve a complete hematologic response after ASCT tend to have better overall survival (OS). However, transplant-related mortality (TRM) and clinical complications during ASCT remain significant challenges and major concerns.

Methods: We reviewed patients with AL amyloidosis who underwent ASCT between 2016 and 2024 at Beneficência Portuguesa de São Paulo to assess the procedure’s safety and long-term outcomes. Our analysis focused on patient baseline characteristics, progression-free survival (PFS), intensive care unit (ICU) admission rates, and overall survival (OS).

Results: Twenty-seven patients met the criteria for this retrospective study. The median age was 60 years (95% CI, 38-70). Seventeen patients (63%) had an ECOG score of 0, and eleven (40%) had a Mayo Cardiac score of 1. Cardiac involvement was present in 11 patients, and renal involvement in 23. Among the cohort, 81% (95% CI, 61-92%) received ASCT as part of first-line therapy, while five patients (18%) received no therapy prior to ASCT. Twelve patients (44%) received a CyBorDex regimen, and nine (33%) received a Dara-based quadruplet regimen. The most commonly used conditioning regimen was Melphalan 200 mg/m² (55.6%), with the remaining patients receiving 140 mg/m².



During hospitalization, 11 patients experienced congestive heart failure decompensation (4 profile ‘B’ and 7 profile ‘C’), with a higher risk observed in patients with pre-existing cardiac dysfunction (OR = 5.2, 95% CI, 0.92-47, p = 0.06). None of the patients were on renal replacement therapy at baseline; however, 4 required hemodialysis during hospital follow-up. There were no in-hospital deaths in this cohort, although 33% of patients were admitted to the ICU within 30 days of follow-up (95% CI, 16-51%).



The OS and PFS rates at 2 years, estimated by the Kaplan-Meier method, were 88% (95% CI, 73-100) and 89% (95% CI, 76-100) respectively, with no early deaths (within 100 days of ASCT).

Conclusions: The present analysis reiterates the vital importance of careful patient selection for ASCT, as complications can occur and may be serious. Therefore, a center's experience is fundamental to guaranteeing the best outcomes. The vast majority of patients in our cohort remained alive, with no transplant-related deaths within the first 100 days.