Researchers Develop Prognostic Model for Survival in Patients With MF Undergoing Allo-HCT

New research demonstrates the efficacy of a prognostic model of survival for patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT) for myelofibrosis (MF).

The model was tested on 2 groups of patients: 1 each from the United States (the Center for Blood and Marrow Transplant Research [CIBMTR] cohort) and Europe (the European Bone Marrow Transplant [EBMT] cohort). Results indicate the proposed system “can easily be applied by clinicians consulting patients with MF on transplant outcomes,” study authors wrote.

The analysis was published in Blood Advances.

Allo-HCT is the only curative therapy for MF. Although the Dynamic International Prognostic Scoring System (DIPSS) and DIPSS-plus scoring systems are frequently used for disease risk stratification, these tools were reported mostly in nontransplant cohorts, authors wrote. Disease characteristics and patient- and transplant-related factors all affect outcomes, underscoring the need for a prognostic score in patients with MF undergoing allo-HCT.

To create the model, the researchers used data from the CIBMTR registry to identify disease-, patient-, and transplantation-specific variables associated with outcomes in these patients. This cohort served as the training set, they added. To determine if the tool was prognostic of relapse, transplant-related mortality, and disease-free survival (DFS), the model was validated on the EBMT registry cohort.

A total of 623 patients made up the CIBMTR cohort. All individuals underwent allo-HCT between 2000 and 2016. After the researchers identified factors prognostic of mortality, a weighted score using these factors was assigned to 623 patients in the EBMT registry, the researchers explained.

Analyses revealed:

• Age above 50 (HR, 1.39; 95% CI, 0.98-1.96), and human leukocyte antigen (HLA)–matched unrelated donor (HR, 1.29; 95% CI, 0.98-1.7) were associated with increased hazard of death and were assigned 1 point
• Hemoglobin lower than 100 g/L at time of transplant (HR, 1.63; 95% CI, 1.2- 2.19) and a mismatched unrelated donor (HR, 1.78; 95% CI, 1.25- 2.52) were assigned 2 points
• The 3-year overall survival (OS) in patients with a low (1-2 points), intermediate (3-4 points), and high score (5 points) were 69% (95% CI, 61%-76 %), 51% (95% CI, 46%-56.4 %), and 34% (95% CI, 21%-49%), respectively (P < .001)
• Increasing score was predictive of increased transplant-related mortality (P = .0017) but not for relapse (P = 0.12)
• The derived score was predictive for OS (P < .001) and transplant-related mortality (P = .002) but not relapse (P =. 17) in the EBMT cohort as well

Overall, the study identified 3 clinically relevant variables prognostic of OS, DFS, and transplant-related mortality in patients with MF undergoing allo-HCT: age, pretransplant hemoglobin level, and donor type.

“Despite significant differences between the 2 cohorts, the proposed model was predictive of outcomes in these 2 large datasets,” authors wrote.

The study included patients treated from 2000 to 2016, a long period of time during which there were changes and advances in the field of stem cell transplantation, the authors noted. One change is the increased use of haplo-identical donors, which were excluded from the current analysis due to small numbers.

Differences in practices between the United States and Europe, including in insurance policies, that affect transplant referrals were beyond the scope of the analysis, marking a limitation.

Despite limitations, “this analysis results in a simple, clinically relevant, and easily applicable score that may help counsel patients with MF undergoing allo-HCT, in addition to the current available risk scores,” researchers concluded.

Reference

Tamari R, McLornan D, Ahn KW, et al. A simple prognostic system in myelofibrosis patients undergoing allogeneic stem cell transplant: a CIBMTR/EBMT analyses. Blood Adv. Published online May 6, 2023. doi:10.1182/bloodadvances.2023009886