Allogeneic hematopoietic stem cell transplantation for myelofibrosis

This review summarizes the current status and new developments in allogeneic hemopoietic stem cell transplantation strategies for patients with myelofibrosis with myeloid metaplasia, focusing on novel concepts of allogeneic transplantation with reduced-intensity conditioning.

No substantial progress has been made in the conventional management of myelofibrosis with myeloid metaplasia. Allogeneic hemopoietic stem cell transplantation represents the only treatment modality with proven curative potential. Standard-dose conditioning regimes followed by allogeneic transplantation are associated with a relatively high transplant-related mortality. Reduced-intensity conditioning regimens have substantially reduced treatment-related mortality. This result is from three studies on myelofibrosis with myeloid metaplasia including more than 60 patients overall. The optimal conditioning regimen for this condition is unknown, in particular the utility of using T-cell depleted stem cells to reduce graft versus host disease is not documented. Emerging concepts include new risk classification for a better provision of the transplant outcome, and splenectomy before transplantation for reducing tumor burden.

The data on hemopoietic stem cell transplantation with reduced-intensity conditioning in myelofibrosis with myeloid metaplasia are encouraging. An accurate risk stratification is a pivotal procedure for selecting patients who will receive the greatest benefit for transplantation. Reduced-intensity conditioning should be further evaluated within clinical trials, in particular for assessing the role of splenectomy and for testing the optimal conditioning regimen.