P-021: Experience with autologous stem-cell transplant (auto-SCT) in patients with systemic light-chain amyloidosis (LA) at our center

Abstract

<h3>Background</h3> Auto-SCT is the standard first-line treatment in patients with LA and good personal status. This procedure achieves haematological responses >70% with an average survival rate of more than 8 years. Depending on patient characteristics and hospital guidelines, prior chemotherapy (CT) is administered, usually with Bortezomib-based regimens. The main determinant of survival in LA is cardiac involvement. The subgroup of patients with cardiac involvement and an indication for Auto-SCT is at the highest risk of complications and mortality and should therefore be strictly selected. <h3>Objective</h3> Our objective is to review the experience in our center with Auto-SCT in patients with LA. <h3>Methods</h3> A retrospective descriptive study was conducted at the Son Espases University Hospital between November 2012 and June 2021. Pre- and post-SCT clinical-biological data, complications during transplantation and progression-free survival (PFS) were analyzed. <h3>Results</h3> Eleven patients with a median age of 59 years at the time of Auto-SCT (range 41-69) were included, of whom 7 were male (64%). Ten patients (90.9%) had renal involvement at diagnosis and 6 (54.5%) had cardiac involvement. According to the Mayo Clinic 2013 prognostic staging score, 6 patients (54.5%) had stage I, 3 patients (27.3%) had stage II and 2 patients (18.2%) had stage IIIb (18.2%). All patients received pre Auto-SCT CT with bortezomib-based regimens. The median pre Auto-SCT left ventricular ejection fraction was 58% (41-79 range). Pre Auto-SCT organ-based chemotherapy response was: 8/10 patients (80%) with renal response; 1/6 patients (16.7%) with cardiac response. Pre Auto-SCT haematological response was: 7 patients (63.6%) complete remission, 1 patient (9%) very good partial response, 1 patient (9%) partial response, 1 patient (9%) stable disease and 1 patient (9%) not assessable. The median number of CD34+ cells infused into Auto-SCT was 3.66×10⁶/kg. 10 patients (90.9%) received G-CSF from day +5. 10 patients (90.9%) developed complications during transplantation, 7 of them requiring admission to the Intensive Care Unit (ICU) with a median of 15 days of admission (range 1-24 days), mainly due to acute pulmonary edema - APE (85.7%). 3/7 patients requiring ICU admission passed away, leaving the Auto-SCT-related mortality rate at 27.3%. With a median follow-up of 36 months (range 5-90), a median PFS and an overall survival rate (OS) of 73% (95%CI 46-99) is observed. PFS and OS match because there are no progression events. <h3>Conclusions</h3> Patients with cardiac involvement prior to Auto-SCT have a high risk of morbidity and mortality, with APE being the main complication in our study. Multidisciplinary management of these patients during Auto-SCT is essential to avoid complications.