The purpose of this study is to evaluate the safety and tolerability of orally administered TG101348 in patients with myelofibrosis.

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.

Inclusion Criteria:

• Diagnosis of myelofibrosis (primary, post-polycythemia vera, or post-essential thrombocythemia)
• At least 18 years of age.
• ECOG PS 0, 1, or 2.

Exclusion Criteria:

• Any chemotherapy, immunomodulatory therapy, immunosuppressive therapy, corticosteroids, or growth factor treatment within 14 days prior to initiation of study drug.
• Major surgery or radiation therapy within 28 days prior to initiation of study drug.