How do JAK2-inhibitors work in myelofibrosis: an alternative hypothesis

Leuk Res. 2009 Dec;33(12):1581-3. doi: 10.1016/j.leukres.2009.06.001. Epub 2009 Jul 1.


The clinical efficacy of JAK2-inhibitors in patients with myelofibrosis, that involves a rapid and massive reduction of spleen enlargement and improvement of clinical symptoms, is not accompanied by significant modifications of hematologic parameters nor of the burden of JAK2V617F allele. Furthermore, clinical improvement has been reported to occur irrespective of patient's JAK2-mutated status. On the other hand, dramatic changes in plasma cytokine levels have been observed. Based on available information about the role of cytokines in the pathogenesis of myelofibrosis, the hypothesis that the clinical efficacy of JAK2-inhibitors could be mainly ascribed to a general down-regulation of cytokine production and cytokine signaling is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

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


  • Protein Kinase Inhibitors
  • Janus Kinase 2