A case series of allo-HSCT in patients with MF and SVT

Splanchnic vein thromboses (SVT) are atypical clots associated with myeloproliferative neoplasms.¹ Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is used to treat patients with myeloproliferative neoplasms, but the impact of SVT on the success of allo-HSCT is unknown.

Below, we summarize a case series on the impact of SVT in patients with myelofibrosis (MF) undergoing allo-HSCT presented by Smallbone.¹ during the 2024 Transplantation & Cellular Therapy Meetings of ASTCT and CIBMTR.

Patient population¹

• Patients with MF undergoing allo-HSCT with and without SVT were included in this retrospective case series analysis.
• Overall, patients were aged 53 years, and a greater proportion were female compared with males (66.6% vs 33.3%).
  • 50% received a matched related donor vs matched unrelated (25%), haploidentical (17%), or mismatched (8%).
  • The majority of patients were assigned fludarabine and busulfan and/or thiotepa (67%) compared with fludarabine and melphalan and/or total body irradiation plus antithymocyte globulin (25%), and busulfan and cyclophosphamide (8%).
• The primary objectives were transplantation, hepatic- and thrombosis-related outcomes.

Key findings¹

• The analysis included 334 patients in the screening and 12 identified with SVT prior to allo-HSCT.
• Complete response was reported in 92% and relapse in 8%
  • After 47.5 months median follow-up 58.3% remained disease-free and 5-year overall survival was 64%.
• Five patients died and eight developed graft-versus-host disease post transplant (Figure 1).
  • All patients who developed liver-related outcomes and died had a pre-HCT Model for End-Stage Liver Disease score >10, pre- or post-HCT variceal bleeding, and did not achieve recanalization of SVT.

Figure 1. A Cause of death and B transplant outcomes in patients with SVT and MF who underwent allo-HSCT* 

GvHD, graft-versus-host-disease, MF, myelofibrosis; SVT, splanchnic vein thrombosis.
*Adapted from Smallbone, et al.¹