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 (7 patients needed Plerixafor) and underwent transplantation. Median follow-up was 106 weeks (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. 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. 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.

Post-Transplantation Cyclophosphamide and Tacrolimus for Graft-versus-Host Disease Prevention after Allogeneic Hematopoietic Cell Transplantation from HLA-Matched Donors Has More Advantages Than Limitations.

This study compared the efficacy of graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (PTCy) and tacrolimus (Tac) versus other regimens in 272 adults undergoing peripheral blood (PB) allogeneic hematopoietic cell transplantation (allo-HCT) from HLA-matched donors. Of these 272 patients, 95 (34.9%) received PTCy/Tac. The times to neutrophil and platelet engraftment were longer in the PTCy/Tac group (20 days versus 16 days for neutrophils and 19 days versus 12 days for platelets). The day +30 cumulative incidence (CuI) of bacterial bloodstream infection was higher in the PTCy/Tac group (43.2% versus 13.0%; P < .001). The CuIs of grade II-IV and grade III-IV acute GVHD (aGVHD) at day +180 were 14.7% and 4.2%, and the CuI of moderate/severe cGVHD at 2 years was 2.4% in the PTCy/Tac group and 41.8% (hazard ratio [HR], .29; P < .001), 15.8%, (HR, .24; P = .007), and 47.0% (HR, .05; P < .001), respectively, in the no-PTCy group. The duration of immunosuppression was shorter in patients receiving PTCy/Tac (6.2 months versus 9.0 months; P < .001). PTCy/Tac patients had higher OS (2 years: 74.3% versus 60.9%; HR, .54; P = .012), lower NRM (2 years: 8.6% versus 15.8%; HR, .54; P = .11), comparable CuI of relapse (2 years: 26.0% versus 24.4%; HR, 1.03; P = .89), and higher GRFS (2 years: 59.1% versus 16.7%; HR, .32; P < .001). Using PTCy/Tac in HLA-matched PB allo-HCT improved transplantation outcomes at out institution compared with previous prophylactic regimens, including a higher probability of survival despite more delayed engraftment and a higher rate of bacterial infection.

A reproducible and safe at-home allogeneic haematopoietic cell transplant program: first experience in Central and Southern Europe.

In 2015, we implemented an at-home allogeneic haematopoietic cell transplant (allo-HCT) program. Between 2015 and 2018, 252 patients underwent allo-HCT; 41 patients underwent allo-HCT in the at-home program (46% myeloablative; 63% unrelated donor; 32% posttransplant cyclophosphamide), and these patients were compared with 39 in-patients; safety, capacity to release beds for other programs, and economic efficiency cost were evaluated. We observed a lower incidence of febrile neutropenia in the at-home group compared with that in the in-patient group (32% versus 90%; p < 0.0001), whereas the incidence of aspergillosis was similar among groups (at-home 1% versus in-patient 3%; p = 0.5). The at-home patients showed a lower incidence of 1-year severe graft-versus-host disease (GVHD; 10% versus 29%; p = 0.03). There were no differences in 1-year transplant-related mortality, relapse, or overall survival among groups. The re-admission rate in the at-home group was 7%. The at-home setting was less expensive (9087 €/transplant), and its implementation increased capacity by 10.5 allo-HCTs/year. Moreover, a chimeric antigen receptor T-cell program could be established without increasing beds. Thus, our at-home allo-HCT program may be a safe modality to reduce febrile neutropenia and acute GVHD, resulting in lower re-admission rates.