Outpatient management of patients conditioned with Fludarabine and Treosulfan prior to allogeneic hematopoietic cell transplantation.

Abstract

Background: Allogenic hematopoietic cell transplantation (allo-HCT) with myeloablative conditioning traditionally requires 30 days long hospitalizations after stem cell infusion. However, advancements in supportive and prophylactic care have allowed for a trend towards outpatient management of allo-HCT, potentially leading to improved patient quality of life and increased procedure cost-effectiveness. In 2014, Fludarabine and Treosulfan (FluTreo) conditioning was introduced as a myeloablative regimen with reduced toxicity at Copenhagen University Hospital, Rigshospitalet (CUH). After gaining experience with the regimen, an outpatient program was established. This study shares the outcome of outpatient conditioning with FluTreo allo-HCT at CUH.

Objective: To investigate safety and feasibility of outpatient FluTreo allo-HCT. Furthermore, to investigate the potentially enhanced cost-effectiveness of outpatient allo-HCT primarily through reduction in hospitalization days compared to the 30 days hospitalization associated with standard myeloablative conditioning.

Study design: This retrospective study included all patients undergoing FluTreo allo-HCT due to malignant diseases (n = 124) at CUH from 2018 to 2022. Patients received outpatient treatment (n = 91) unless certain circumstances required planned hospitalization (n = 33). As conditioning, patients received intravenous Fludarabine 90 mg/m² and Treosulfan either 30 or 42 g/m². Statistical analyses included descriptive statistics and Kaplan Meier survival analysis.

Results: The median duration of hospitalization in the outpatient group was 4 days (Q1-Q3 0-12.5) from day -6 to +28 compared to a median of 28 days (Q1-Q3 26-34) in the inpatient group. 32 (35%) in the outpatient group did not require hospitalization within day +28 after transplantation. The remaining 59 patients (65%) were hospitalized after 12 days (Q1-Q3 7-16 days) from start of conditioning, for a median of 10 days (Q1-Q3 5-18). The outpatient group required significantly less IV antibiotics, IV opioids and parenteral nutrition than the inpatient group, despite no difference in treatment toxicity, acute graft-versus-host disease, or relapse between the groups. The outpatient group experienced no early deaths during the first 3 months after transplantation and 1-year non-relapse mortality was 6%.

Conclusion: Outpatient allo-HCT with FluTreo conditioning is feasible and safe in a selected group of patients, significantly reducing hospitalization days without compromising patient outcomes. Outpatient FluTreo allo-HCT potentially stands as a more cost-effective and patient-friendly alternative compared to traditional in-patient management.