Hypothesis: how do JAK2-inhibitors work in myelofibrosis

Leuk Res. 2009 Sep;33(9):1156-7. doi: 10.1016/j.leukres.2009.04.011. Epub 2009 May 17.


JAK2-inhibitors rapidly reduce spleen enlargement and clinical symptoms in persons with myelofibrosis but have little, if any, effect on the WBC, anemia, decreased platelets or bone marrow fibrosis. Also, JAK2-inhibitors are active in persons with and without the JAK2-mutation. Based on these and other data we suggest that the predominant effect of JAK2-inhibitors in persons with myelofibrosis is on normal rather than the abnormal clones.

MeSH terms

  • Humans
  • Janus Kinase 2 / antagonists & inhibitors*
  • Janus Kinase 2 / genetics
  • Mutation
  • Primary Myelofibrosis / drug therapy*
  • Protein Kinase Inhibitors / therapeutic use*


  • Protein Kinase Inhibitors
  • JAK2 protein, human
  • Janus Kinase 2