 TG101348 is a potent small molecule inhibitor of Janus kinase 2 JAK2. This is a first-in-human study that will include a dose-escalation phase, to establish the maximum tolerated dose, and an expanded cohort, dose-confirmation phase. The safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary clinical activity of TG101348 in patients with myelofibrosis will be evaluated. 