Allogeneic Hematopoietic Stem Cell Transplantation in Myelofibrosis: Evolving Indications, Conditioning Strategies,...

Background/Objectives: Myelofibrosis (MF) is a clonal myeloproliferative neoplasm driven by dysregulated JAK-STAT signaling, characterized by progressive marrow fibrosis, splenomegaly, constitutional symptoms, and increased risk of leukemic transformation. Allogeneic hematopoietic stem cell transplantation (allo-HCT) remains the only potentially curative intervention. In Italy, allo-HCTs for myeloproliferative neoplasms (MPN, i.e., myelofibrosis, polycythaemia vera, and essential thrombocythaemia combined) increased by 163% from 2015 to 2025; MF-specific procedure counts were not separately available in this registry export, so this figure should not be read as MF-specific, with MPN accounting for 8% of all allogeneic procedures (n = 171) in 2025, showing a 29.5% year-on-year increase from 2024. Concurrently, the demographic profile shifted, with individuals aged 60 and over representing 38% of all recipients, surpassing other age groups for the first time in 2025. Results: This review synthesizes current evidence on transplant indications and timing, pre-transplant management, donor selection, and conditioning regimen optimization, emphasizing the emerging role of treosulfan-based and dual-alkylator platforms, including the thiotepa-treosulfan-fludarabine (TTF) regimen. Post-transplant molecular MRD monitoring and relapse management are also discussed. Three-year overall survival in myelofibrosis ranges from about 59% to 67%, depending on donor type, with outcomes improving due to better patient selection, optimized conditioning, and supportive care. Conclusions: Prospective randomized trials are urgently needed to validate optimal conditioning intensity, the role of novel JAK inhibitors in the peri-transplant period, and MRD-guided pre-emptive strategies.