Study of Pomalidomide in Persons With Myeloproliferative-Neoplasm-Associated Myelofibrosis and RBC-Transfusion-Dependence

Inclusion Criteria:

• Age ≥ 18 years

• Myeloproliferative-neoplasm (MPN)-associated myelofibrosis

• RBC-transfusion-dependence (global study):

• Average RBC-transfusion frequency ≥ 2 units/28 days over at least the 84 daysimmediately prior to randomization. There must be no interval > 42 days without ≥ 1 RBC-transfusion.

• Only RBC-transfusions given when the hemoglobin ≤ 90 g/L³ are scored in determining eligibility.

• RBC-transfusions due to bleeding are not scored in determining eligibility.

• RBC-transfusions due to chemotherapy-induced anemia are not scored in determiningeligibility.

• Severe anemia (China-specific extension):

• ≥ 2 hemoglobin concentrations ≤ 80 g/L for ≥ 84 days immediately before the day ofenrollment.

• No RBC-transfusion within 6 months prior to enrollment.

• Hemoglobin ≤ 130 g/L at randomization (global study); ≤ 80 g/L at enrollment inthe China-specific extension.

• Bone marrow biopsy within 6 months (global study only).

• Inappropriate to receive blood cell or bone marrow allotransplant, erythropoietinand androgenic steroids

• Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.

• Agree to follow pregnancy precautions as required by the protocol.

• Agree to receive counseling related to teratogenic and other risks ofpomalidomide.

• Agree not to donate blood or semen.

Exclusion Criteria:

• Prior blood cell or bone marrow allotransplant.

• Use of drugs to treat MPN-associated myelofibrosis ≤ 30 days before starting studydrug.

• Treatment with erythropoietin or androgenic steroids ≤ 84 days before starting studydrug.

• Anemia due to reasons other than MPN-associated myelofibrosis.

• Pregnant or lactating females.

• More than 10% blasts by bone marrow examination or more than 10% blasts in blood inconsecutive measurements spanning at least 8 weeks

• Prior history of malignancies,other than the disease being studied, unless the subjecthas been free of the malignancy for ≥ 5 years with the following exceptions:

• Carcinoma in situ of the cervix

• Carcinoma in situ of the breast

• Incidental histologic finding of prostate cancer (T 1a or T 1b using TNM [tumor,nodes, metastasis] clinical staging system)

• Human immunodeficiency virus (HIV) infection, active hepatitis B virus (HBV) orhepatitis C virus (HCV) infections.

• Prior treatment with pomalidomide.

• Allergic reaction or rash after treatment with thalidomide or lenalidomide

• Any of the following laboratory abnormalities:

• Neutrophils < 0.5x10^9 /L

• Platelets < 25 x 10^9 /L

• Estimated glomerular filtration rate (kidney function) < 30 mL/min/1.73 m²

• Aspartate aminotransferase (AST) and alanine transaminase (ALT) > 3.0 x upperlimit of normal (ULN)

• Total bilirubin ≥ 4 x ULN;

• Uncontrolled hyperthyroidism or hypothyroidism.

• Deep venous thrombosis (DVT) or pulmonary embolus (PE) < 6 months before startingstudy drug

• Clinically-important heart disease within the past 6 months