PGY2 Oncology Pharmacy Resident Hospital of the University of Pennsylvania Philadelphia, Pennsylvania, United States
Poster Abstract:
Background: Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curable treatment for various hematologic malignancies but use is limited by patients’ ability to tolerate the preceding conditioning regimen. Reduced intensity conditioning (RIC) is less toxic and allows older and less fit patients to undergo allo-HCT. However, there is no consensus on the optimal RIC regimen due to a lack of prospective, randomized trials. Fludarabine/busulfan (FB) and fludarabine/melphalan (FM) are most commonly used RIC regimens in the United States. Retrospective data suggests FM has lower relapse rates but higher transplant related mortality (TRM) and FB has less toxicity but higher relapse rates. FB was the standard RIC regimen at the Hospital of the University of Pennsylvania (HUP) until 3/2022 when FM was chosen as the standard in an effort to decrease relapse rates. Recently due to a fludarabine shortage, HUP has substituted fludarabine with clofarabine when necessary, although outcome data is lacking with this regimen. Institution-specific outcomes have not been compared since the transition to FM or use of clofarabine/busulfan (CB).
Objectives: The primary endpoint is transplant-related mortality at day 100 (D+100) post-allo-HCT. Secondary endpoints include overall survival (OS) and relapse rates (RR) at D+100 and 1-year, disease-free survival (DFS), graft-versus-host disease (GVHD) incidence, and GVHD relapse free survival (GRFS). Safety outcomes include peak grades of nephrotoxicity, hepatotoxicity, and mucositis according to the Common Terminology Criteria for Adverse Events Version 5.0 and the incidence of veno-occlusive disease and seizures.
Methods: This is a single-center, retrospective, institutional review board approved study that includes adult patients who underwent a RIC allo-HCT with FM, FM, or CB at HUP from April 1, 2017 to August 1, 2023. Patients will be excluded if they received concurrent total body irradiation during conditioning. Data will be collected using the electronic medical record. TRM, RR, DFS, NRM, GVHD, and GRFS will be estimated by cumulative incidence model. OS will be calculated by the Kaplan-Meir method. Multivariate analysis will be performed using the Fine-Gray model for TRM, RR, DFS, GVHD and GRFS and the Cox proportional hazards model for OS.
Results/
Conclusion: Results are pending.
References (must also be included in final poster): 1. Gyurkocza B, Sandmaier BM. Conditioning regimens for hematopoietic cell transplantation: one size does not fit all. Blood. 2014;124(3):344-353. doi:10.1182/blood-2014-02-514778 2. Nath R, Zhou Z, Cerny J, et al. Reduced Intensity Conditioning (RIC) Regimens Hematopoietic Cell Transplantation (HCT) for Acute Myeloid Leukemia (AML): A Comparison of Fludarabine/Busulfan (FB) and Fludarabine/Melphalan (FM) Based Regimens from the CIBMTR. Blood. 2018;132(Supplement 1):3456. doi: https://doi.org/10.1182/blood-2018-99-116795
