Efficacy and Safety of FG-4592 for Treatment of Anemia in Patients With Lower Risk MDS With Low Red Blood Cell Transfusion Burden

This study includes an Open-Label and a Double-Blind component. In each, there is an up to 28
days screen period followed by a treatment period of 52 weeks and a 4 week end of treatment
assessment.

Key Inclusion Criteria:

- Diagnosis of primary MDS classified as very low, low or intermediate risk with <5%
blasts. There is no minimum time from diagnosis except to allow for proper IPSS-R
classification to be made, and to show transfusion dependence.

- RBC transfusion of either 2-4 pRBC units over the 8 weeks prior to randomization or 1
pRBC in two consecutive periods of 8 weeks within the 16 weeks prior to randomization

- No restriction on prior use of ESAs, except no ESA use within 8 weeks prior to
registration/randomization

- Pre-transfusion hemoglobin of <= 10 g/dL,

- ECOG of 0-2 at screen

- History of cured malignancy with no evidence of recurrence for a least 3 years are
eligible

Key Exclusion Criteria:

- Diagnosis of secondary MDS

- Significant myelofibrosis (>2+fibrosis)

- MDS associated with 5q(del) abnormality

- Screen serum erythropoietin level > 400 mIU/mL,

- Clinically significant anemia due to non-MDS etiologies