A Phase 2, Prospective, Randomized, Multicenter, Double-blind, Active-control, Parallel-group Study to Determine the Safety of and to Select a Treatment Regimen of CC-4047 (Pomalidomide) Either as Single-agent or in Combination With Prednisone to Study Further in Subjects With Myelofibrosis With Myeloid Metaplasia

Inclusion Criteria:

- Must sign an informed consent form

- Must be >18 years of age

- Must be diagnosed with myelofibrosis

- Eligibility is based on local pathology review of bone marrow aspirate and biopsy

- Screening total hemoglobin level < 10g/dL or transfusion-dependent anemia defined as
per IWG criteria.

- Must have adequate organ function as demonstrated by the following ≤ 14 days prior to
starting study drug:

- ALT (SGPT)/AST (SGOT) ≤ 3 x upper limit of normal (ULN), [unless upon judgment
of the treating physician, it is believed to be due to extra-medullary
hematopoiesis (EMH)].

- Total Bilirubin <3x ULN or Direct Bilirubin <2 x ULN

- Serum creatinine ≤ 2.0 mg/dL

- Absolute neutrophil count ≥ 1,000/μL (≥ 1 x 10^9/L).

- Platelet count ≥ 50,000 /μL (≥ 50 x 10^9/L).

- Subjects must be willing to receive transfusion of blood products

- ECOG performance status (PS) of 0, 1, or 2 at screening.

- Must be able to adhere to the study visit schedule and other protocol requirements.

- No active malignancies with the exception of controlled prostate cancer, basal cell
or squamous cell carcinoma of the skin, or carcinoma "in situ" of the cervix or
breast.

- Must agree to follow pregnancy precautions as required per the protocol

Exclusion Criteria:

- Known positive status for HIV, hepatitis B carrier, or active hepatitis C infection.

- Previous untoward reaction to corticosteroid (specifically, prednisone) therapy that
was severe enough, in the opinion of the treating physician, to preclude study
participation.

- The use of any growth factors, cytotoxic chemotherapeutic agents (e.g. hydroxyurea
and anagrelide), corticosteroids, or experimental drug or therapy within a minimum of
28 days of starting CC-4047 and/or lack of recovery from all toxicity from previous
therapy to grade 1 or better (e.g. alpha interferon may require 84 days of longer or
washout).

- Prior therapy with CC-4047 or, lenalidomide or thalidomide for MMM. (Prior prednisone
use as a therapy for MMM is allowed, but not within 28 days of starting CC-4047).

- History of deep vein thrombosis or pulmonary embolism within one year of starting
study medication.

- Any serious medical condition or psychiatric illness that would prevent, (as judged
by the treating physician) the subject from signing the informed consent form or any
condition, including the presence of laboratory abnormalities, which places the
subject at unacceptable risk if he/she were to participate in the study or confounds
the ability to interpret data from the study.

- Pregnant or lactating females