2. Diagnosis of primary myelofibrosis (PMF) or post-polycythemia vera (post-PV) MF or post-essential thrombocythemia (post-ET) MF based on the World Health Organization (WHO) criteria or the IWG-MRT criteria, which must be confirmed by BM aspirate and/or biopsy within 6 weeks prior to Screening. Measurement of JAK2 V617F allele burden in BM samples, if not done within 6 months prior to Screening, must be provided with the Screening BM biopsy/aspirate report (patients are eligible regardless of JAK2 mutation status);