An oral medication used to treat bone marrow disorders like myelofibrosis and polycythemia vera.
JAKAFI/JAKAFI XR is a kinase inhibitor indicated for treatment of: intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis in adults. ( 1.1 ) polycythemia vera in adults who have had an inadequate response to or are intolerant of hydroxyurea. ( 1.2 ) steroid-refractory acute graft-versus-host disease in adult and pediatric patients 12 years and older. ( 1.3 ) chronic graft-versus-host disease after failure of one or two lines of systemic therapy in adult and pediatric patients 12 years and older. ( 1.4 ) 1.1 Myelofibrosis JAKAFI/JAKAFI XR is indicated for treatment of intermediate or high-risk myelofibrosis (MF), including primary MF, post-polycythemia vera MF, and post-essential thrombocythemia MF in adults. 1.2 Polycythemia Vera JAKAFI/JAKAFI XR is indicated for treatment of polycy…
12.1 Mechanism of Action Ruxolitinib, a kinase inhibitor, inhibits Janus Associated Kinases (JAKs), JAK1 and JAK2, which mediate the signaling of a number of cytokines and growth factors that are important for hematopoiesis and immune function. JAK signaling involves recruitment of STATs (signal transducers and activators of transcription) to cytokine receptors, activation, and subsequent localization of STATs to the nucleus leading to modulation of gene expression. MF and PV are myeloproliferative neoplasms (MPNs) known to be associated with dysregulated JAK1 and JAK2 signaling. In a mouse model of JAK2V617F-positive MPN, oral administration of ruxolitinib prevented splenomegaly, preferent…
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Plain-English summaries and drug-class explainers are written and reviewed by the Priya Life Science editorial team, led by Sreepriya Prasannan (MSc Digital Transformation of Life Sciences (Innopharma Education / Griffith College); MSc & BSc Botany). Data is retrieved automatically from the sources above and cross-checked with AI-assisted verification (Anthropic's Claude) — brand and generic names are matched against the exact FDA product record so that a combination product or a different formulation cannot be mistaken for the drug on this page. An editor reviews the result before publication. We describe this in full in our editorial standards and corrections policy. The FDA data on this page was last retrieved on 5 Aug 2026.