Cyclophosphamide-free Mobilisation Increases Safety While Preserving the Efficacy of Autologous Haematopoietic Stem Cell Transplantation in Refractory Crohn's Disease Patients.

Background and Aim: Autologous haematopoietic stem cell transplantation [AHSCT] is a therapeutic option for refractory Crohn's disease [CD]. However, high adverse event rates related to chemotherapy toxicity and immunosuppression limit its applicability. This study aims to evaluate AHSCT's safety and efficacy using a cyclophosphamide [Cy]-free mobilisation regimen.
Methods: A prospective, observational study included 14 refractory CD patients undergoing AHSCT between June 2017 and October 2022. The protocol involved outpatient mobilisation with G-CSF 12-16 μg/kg/daily for 5 days, and optional Plerixafor 240 μg/d [1-2 doses] if the CD34 + cell count target was unmet. Standard conditioning with Cy and anti-thymocyte globulin was administered. Clinical, endoscopic, and radiological assessments were conducted at baseline and during follow-up.
Results: All patients achieved successful outpatient mobilisation [seven patients needed Plerixafor] and underwent transplantation. Median follow-up was 106 weeks (interquartile range [IQR] 52-348). No mobilisation-related serious adverse events [SAEs] or CD worsening occurred. Clinical and endoscopic remission rates were 71% and 41.7% at 26 weeks, 64% and 25% at 52 weeks, and 71% and 16.7% at the last follow-up, respectively. The percentage of patients who restarted CD therapy for clinical relapse and/or endoscopic/radiological activity was 14% at 26 weeks, 57% at 52 weeks, and 86% at the last follow-up, respectively. Peripheral blood cell populations and antibody levels post-AHSCT were comparable to Cy-based mobilisation.
Conclusions: Cy-free mobilisation is safe and feasible in refractory CD patients undergoing AHSCT. Although relapse occurs in a significant proportion of patients, clinical and endoscopic responses are achieved upon CD-specific therapy reintroduction.
(© The Author(s) 2024. Published by Oxford University Press on behalf of European Crohn’s and Colitis Organisation. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)