[Novel therapeutic options in the treatment of BCR/ABL-negative myeloproliferative neoplasms]

Since the discovery of the JAK2V617F mutation in essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF) in 2005, the field of myeloproliferative neoplasms (MPN) experiences a significant gain of knowledge. Based on the novel insights in the molecular pathomechanisms of MPN many innovative drugs have been developed that are currently under investigation in clinical trials. Most data are available on the JAK inhibitors, the so called "ATP mimetics" for the treatment of MF. Recent data from two large phase-III studies showed that the JAK1 /2 inhibitor Ruxolitinib is very effective in the reduction of spleen size and the improvement of quality of life in MF patients. Beside JAK inhibitors, immunomodulatory drugs (IMiD) are currently under investigation. Here, pomalidomide showed significant activity in several phase-II studies in MF patients. In addition, other kinase inhibitors as well as histone deacetylase (HDAC) inhibitors and inhibitors of the mTOR signalling pathway are currently evaluated in clinical trials. Based on their potential synergistic action combination therapy of these substances represents another option for MPN therapy.In this review the most recently published studies using innovative treatment strategies in MPN patients are reported, and some future aspects for MPN treatment are adressed.