Ruxolitinib is a janus-associated kinase inhibitor indicated to treat bone marrow cancer, specifically intermediate or high-risk myelofibrosis. FDA approved on November 16, 2011.
Humans and other mammals
Treatment of intermediate or high-risk myelofibrosis, including primary myelofibrosis, post-polycythemia vera (post-PV) myelofibrosis and post-essential thrombocythemia (post-ET) myelofibrosis. [Lexicomp] Myeolofibrosis is the proliferation of abnormal bone marrow stem cells which cause fibrosis (the excessive formation of connective tissue).
The mean half-maximal inhibitory concentration (IC50) for JAK 1 and JAK 2 are 2.8 nmol/L and 3.3 nmol/L respectively. After administration of ruxolitinib, a decrease in levels of phosphorylated STAT (marker for JAK activity) in a dose-dependent manner can be observed. Pharmacodynamic resistance has not been observed.
Mechanism of action
Ruxolitinib is a kinase inhibitor that is selective for the Janus Associated Kinases (JAK) 1 and 2. These kinases are responsible for the mediation of cytokine and growth factor signalling which in turn effect immune function and hematopoiesis. The signalling process involves signal transducers and transcription activators (STAT) which modulate gene expression. Patients with myelofibrosis have abnormal JAK1 and JAK2 activity thus ruxolitinib works to regulate this.
Drug Info/Drug Targets: DrugBank 3.0: a comprehensive resource for 'omics' research on drugs. Knox C, Law V, Jewison
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Nucleic Acids Res. 2011 Jan; 39 (Database issue):D1035-41. | PMID:21059682