HSP90 Inhibitor, AUY922, in Patients With Primary Myelofibrosis (PMF), Post-Polycythemia Vera Myelofibrosis (Post-PV MF), Post-Essential Thrombocythemia Myelofibrosis (Post-ET MF), and Refractory PV/ET

AUY922 will be administered as an intravenous infusion over 60 minutes, on a once weekly schedule. A cycle on study will be defined as 28 days. The dose to be studied are 70 mg/m2 and 55 mg/m2 if DLTs are identified in the first 3-6 patients. The same schedule of administration will be used for all patients in this trial.