Momelotinib in Transfusion-Dependent Adults With Primary Myelofibrosis (PMF) or Post-polycythemia Vera or Post-essential Thrombocythemia Myelofibrosis (Post-PV/ET MF)

Key Inclusion Criteria:

- Diagnosis of PMF or Post PV/ET-MF

- Requires myelofibrosis therapy, in the opinion of the investigator

- High risk OR intermediate-2 risk defined by dynamic international prognostic scoring
system (DIPSS) OR intermediate-1 risk defined by DIPSS and associated with symptomatic
splenomegaly and/or hepatomegaly

- Transfusion dependent at baseline, defined as ≥ 4 U red blood cell (RBC) transfusion
in the 8 weeks prior to first dose of MMB

- Acceptable organ function as evidenced by the following:

- Platelet Count ≥ 50 x 10^9/L

- Aspartate aminotransferase (AST/SGOT) and alanine aminotransferase (ALT/SGPT) ≤ 3
x upper limit of normal (ULN) or AST or ALT ≤ 5 x ULN if liver is involved by
disease process as judged by the investigator

- Serum creatinine ≤ 2.0 mg/dL or calculated creatinine clearance of ≥ 60 mL/min

- Direct bilirubin ≤ 2.0 x ULN

- Life expectancy of > 24 weeks

- Males and females of childbearing potential who engage in heterosexual intercourse
must agree to use protocol specified method(s) of contraception

- Lactating females must agree to discontinue nursing before MMB administration

- Able to understand and willing to sign the informed consent form

Key Exclusion Criteria:

- Prior splenectomy

- Splenic irradiation within 3 months prior to the first dose of MMB

- Prior treatment with MMB

- Known positive status of human immunodeficiency virus (HIV)

- Chronic active or acute viral hepatitis A, B, or C infection (testing required for
hepatitis B and C), or hepatitis B or C carrier

- Use of strong cytochrome P450 3A4 (CYP3A4) inducer within 2 weeks prior to the first
dose of MMB

- Uncontrolled intercurrent illness per protocol

- Treatment with a Janus kinase (JAK) inhibitor within 21 days of the planned first dose
of MMB

- Presence of peripheral neuropathy ≥ Common Terminology Criteria for Adverse Events
(CTCAE) Grade 2

- Unwilling or unable to undergo a MRI per requirements in the study protocol

- Unwilling to consent to genomics sampling

Note: Other protocol defined Inclusion/Exclusion criteria may apply.