Development of ruxolitinib as a myelofibrosis therapy

Myelofibrosis (MF) is a hematologic malignancy characterized by proliferation of an aberrant myeloid-derived stem cell clone, leading to inefficient hematopoiesis and bone marrow fibrosis. Typical clinical manifestations include progressive anemia and splenomegaly, which leads to several debilitating symptoms, including fatigue, night sweats, itching, appetite loss, and bone pain. Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway dysregulation is a common feature of MF. Ruxolitinib, an oral JAK1/JAK2 inhibitor, was recently approved by the US Food and Drug Administration and European Medicines Agency for the treatment of MF patients. In clinical trials, patients treated with ruxolitinib had significant reductions in spleen size and improvements in their constitutional symptoms and quality of life (QoL), with possibly prolonged survival. The most common adverse events were anemia and thrombocytopenia. Here, we review the most recent clinical data on ruxolitinib and discuss its use in MF patients.