Effect of treatment with a JAK2-selective inhibitor, fedratinib, on bone marrow fibrosis in patients with myelofibrosis

Catriona Jamieson, Robert Hasserjian, Jason Gotlib, Jorge Cortes, Richard Stone, Moshe Talpaz, Jürgen Thiele, Scott Rodig, Olga Pozdnyakova

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


Background: Progressive bone marrow fibrosis (BMF) is a cardinal feature of many myeloproliferative neoplasms (MPNs) and there is a documented association between the severity of BMF and overall prognosis. We conducted an exploratory analysis of sequential BMF data from two phase I studies of long-term treatment with the Janus kinase 2 (JAK2) inhibitor fedratinib in patients with myelofibrosis. Methods: Bone marrow samples were obtained at baseline and after every six cycles (24weeks) of daily fedratinib treatment. Fibrosis was centrally assessed by three independent haematopathologists, who were blinded to the patients' data, and graded according to European Consensus Myelofibrosis Grading Criteria. The analysis population comprised patients with a baseline BMF grade ≥1, and at least one post-baseline BMF grade assessment. Changes in BMF grade compared with baseline were classified as improvement (≥1 grade reduction), stabilisation (no change in any baseline BMF grade <3) or worsening (≥1 grade increase). Results: Twenty-one patients were included in the analysis. A total of 153 bone marrow samples were analysed. Improvement or stabilisation of BMF from baseline was recorded in 15 of 18 (83%) evaluable patients at cycle 6 and in four of nine (44%) evaluable patients at cycle 30. Two patients achieved resolution of their BMF (grade=0) by cycle 12. Conclusions: This exploratory analysis indicates that improvement or even resolution of BMF may be achievable with JAK2 inhibitor therapy in some patients with MPNs and myelofibrosis.

Original languageEnglish (US)
Article number294
JournalJournal of Translational Medicine
Issue number1
StatePublished - Sep 10 2015
Externally publishedYes


  • Fibrosis
  • Janus kinase inhibitor
  • Myelofibrosis
  • Myeloproliferative neoplasms
  • Philadelphia chromosome-negative

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)


Dive into the research topics of 'Effect of treatment with a JAK2-selective inhibitor, fedratinib, on bone marrow fibrosis in patients with myelofibrosis'. Together they form a unique fingerprint.

Cite this