Autologous Stem Cell Transplantation (ASCT) for Light Chain (AL) Amyloidosis: A Single-Center Report

Context:

Since the 1990s, high-dose intravenous melphalan followed by ASCT has been a cornerstone in treating AL amyloidosis. In recent years, there has been an increase in the therapeutic arsenal for this condition; however, ASCT, based on melphalan, continues to be recommended due to its high response rates and prolonged duration, leading to long periods of remission, including better overall survival (OS).

Objective/Methods:

This is an observation retrospective case-series study encompasses a consecutive cohort of patients submitted to ASCT to treat systemic light chain amyloidosis. We reviewed files of patients who underwent ASCT between 2016 and 2024 at Beneficência Portuguesa de São Paulo to assess the procedure's safety. Our analysis focused on patient baseline characteristics, progression-free survival (PFS), intensive care unit (ICU) admission rates, and overall survival (OS). The present study received approval from the local ethics committee and adhered to the principles outlined in the Declaration of Helsinki and the Guidelines for Good Clinical Practice.

Results:

Twenty-seven patients met the criteria for this retrospective study. The median age was 60 years (95% CI, 38-70) and time from diagnosis to aHSCT was 232 days (IQR 170-387). Seventeen patients (63%) had an ECOG score of 0, and 11 (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, after an induction, while five patients (18%) received no therapy prior to ASCT. Twelve patients (44%) received a CyBorDex regimen, and 9 (33%) received a Dara-based quadruplet regimen. The most used conditioning regimen was melphalan 200 mg/m² (55.6%), with the remaining patients receiving 140 mg/m².The vast majority (24/27) received non-cryopreserved ASCT. During hospitalization, 11 patients experienced congestive heart failure decompensation (four profile ‘B’ and seven 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, four 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 cohort's median follow up was 749 days, the overall survival (OS) at 2 years was 88% (CI95% 73-100) and progression free survival (PFS) at 2 years was 89% (CI95% 76-100),with no early deaths (within 100 days of ASCT).

Conclusion:

The present analysis reiterates the critical importance of of meticulous patient selection for selection for ASCT, given the potential for serious complications. Therefore, a transplant center's experience plays pivotal role in ensuring optimal outcomes. In our cohort, the majority of patients survived, with no transplant-related deaths occurring within the first 100 days. Real-world studies are crucial in medical research as they provide insights into the effectiveness, safety, and practical application of treatments and interventions in diverse, everyday clinical settings, improving patient outcomes by providing a more comprehensive understanding of treatment efficacy and safety in real-world conditions.

Scheinberg:BMS: Consultancy; Novartis: Consultancy, Speakers Bureau; Alnylam: Research Funding; AstraZeneca: Consultancy, Speakers Bureau; Janssen: Consultancy; Roche: Consultancy, Speakers Bureau; Pfizer: Consultancy, Research Funding, Speakers Bureau; Astellas: Consultancy.