Conditioning regimen intensity has a significant impact on clinical outcomes following allogeneic hematopoietic cell transplant (HCT) for patients with myelofibrosis (MF), according to a study presented at the 2021 TCT Meetings of ASTCT & CIBMTR Digital Experience
In this study, researchers assessed 66 patients who underwent human leukocyte antigen-matched related donor (MRD) or matched unrelated donor (MUD) HCT between January 2000 and December 2018 at Stanford University. They collated data on demographics, HCT Comorbidity Index score, Dynamic International Prognostic Scoring System score, splenic treatment, donor type, and conditioning regimen, using Kaplan-Meier estimates to calculate overall survival (OS) and progression-free survival (PFS).
The researchers observed that in MRD HCT, OS varied by conditioning intensity (P=0.02), and the median OS following non-myeloablative conditioning (NMA) was 1.2 years (95% confidence interval [CI], 0.2-6.3), which was not achieved in myeloablative (95% CI, 6.0 to not reached) or reduced-intensity conditioning HCT (95% CI, 0.4 to not reached), they noted. Furthermore, in MUD HCT, OS also differed by conditioning intensity (P=0.04), with a median OS following NMA of 0.6 years (95% CI, 0.4-1.7); median OS was 0.4 years in the MAC cohort (95% CI, 0.1-3.3) and 5.2 years in the reduced intensity cohort (RIC; 95% CI, 0.04 to not reached). The researchers further noted that in both MRD and MUD HCT, the PFS differed significantly by conditioning regimen intensity, with reduced-intensity conditioning demonstrating superior PFS in MRD.
“Our results suggest that conditioning regimen intensity has a significant effect on outcomes after MRD and MUD HCT in MF. Outcomes with NMA regimens were uniformly poor irrespective of donor type. With myeloablative conditioning, survival was better with MRD; however, with reduced-intensity conditioning, both MRD and MUD transplant produced equally superior survival. Careful selection of conditioning regimen for the given donor type and excluding NMA regimens can improve outcomes in MF,” the researchers concluded.
Shiraz P, et al. Impact of Conditioning Regimen and Donor Type on Outcomes of Allogeneic Stem Cell Transplant for Myelofibrosis – a Single Institutional Experience. Published for the 2021 TCT Meetings of ASTCT & CIBMTR Digital Experience; February 8-12, 2021.