Safety and Efficacy Study of Sotatercept in Adults With Transfusion Dependent Diamond Blackfan Anemia

Inclusion Criteria: * \>/= 18 years of age * DBA diagnosed * RBC transfusion- dependence (defined as \>/= 10 cc/kg of RBC per 28 days average) * Karnofsky performance scale \>/= 70 * Females of childbearing potential are to use birth control during study participation and for 112 days following the last dose of sotatercept * Males must agree to use a latex condom during any sexual contact with females of childbearing potential while participating in the study and for 112 days following the last dose of sotatercept * Agreement to adhere to the study visit schedule, understand and comply with all protocol requirements * Understand and sign a written informed consent Exclusion Criteria: * Creatinine clearance \< 30 ml/min * SGOT \> 3x upper limit of normal, SGPT \> 3x upper limit normal, or bilirubin \>3x upper limit normal * Heart disease (NY Heart Association classification of \>/= 3 * History of hypertension * Subjects currently responsive to corticosteroids for treatment of Diamond Blackfan anemia * Treatment with another investigational drug or device \<56 days pre-study entry * Pregnant or lactating females * Cancer