Luspatercept + Darbepoetin in MDS

Luspatercept will be administered every 3 weeks (21 days) at a starting dose of 1.0 mg/kg (Dose Level 0). Luspatercept will be administered to participants by the study staff at the clinical site and administration will be documented in the participant's source record. Participants must have Hgb, blood pressure and weight assessed (changes of body weight of ≤ ± 5% do not require a dose adjustment) prior to each luspatercept dose administration. Subcutaneous injections will be given in the upper arm, thigh, and/or abdomen. Volume for subcutaneous injection will be per institutional standard/guidelines.

Darbepoetin alfa will be administered every 3 weeks (21 days), at a starting dose of 300 ug (Dose Level 0). Darbepoetin alfa will be administered to participants by the study staff at the clinical site and administration will be documented in the participant's source record. Darbepoetin alfa will be administered as a subcutaneous injection by the site staff in the upper arm, thigh, and/or abdomen per institutional standard/guidelines.