A Phase 2a Study To Evaluate The Pharmacokinetics, Safety, Efficacy, Tolerability, And Pharmacodynamics of Sotatercept (ACE-011) for the Correction of Anemia in Subjects With End-stage Renal Disease on Hemodialysis.

Cmax is a pharmacokinetic parameter defined as the observed maximum concentration of the study drug in the serum and/or blood. Cmax will be estimated from the sotatercept concentration versus time data using noncompartmental method.

Time to observed maximum concentration (Tmax) is defined as the amount of time in days for a drug to reach the maximum concentration after administration.

AUC-28 days is defined as area under the concentration-time curve over the first 28-day dosing interval

Area under the concentration-time curve from time zero extrapolated to infinity. Only Part 1 pharmacokinetic evaluable participants were pre-specified to be evaluated in this endpoint.

Apparent Total Clearance (CL/F) is defined as the volume of plasma from which the study drug is completely removed per unit of time. It is equal to the drug dose divided by the area-under-the-curve.

Apparent volume of distribution based on terminal phase (Vz/F) is defined as the apparent volume in which the current amount of drug in the body must be dispersed in order to give the current plasma concentration. Apparent volume of distribution is important for determining the dose required to produce a desired plasma concentration of the drug.

Terminal plasma half-life (t1/2,z) is the time taken for concentration of the study drug to decrease from its maximum concentration (Cmax) to half of Cmax in the blood plasma.

An Adverse Event (AE) is defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a clinical investigation participant administered study treatment and that does not necessarily have a causal relationship with this treatment.

Number of participants with hemoglobin > 12g/dL including Hb values obtained after first study drug dose and before any rescue.

Proportion of participants with rise in hemoglobin (Hb) > 2 g/dL during a 4-week period including Hb values obtained after first study drug dose and before any rescue.

Blood pressure was generally recorded on the day of dialysis and represent pre-dialysis values. Baseline is defined as blood pressure measurements recorded on Day 1 of the first dose administered.

The change in follicle stimulating measured at pre-specified timepoints throughout the treatment period.

Number of participants with hemoglobin > 10g/dL including Hb values obtained after first study drug dose and before any rescue. Baseline is defined as hemoglobin measurements recorded on Day 1 of the first dose administered.

Number of participants with a change from in hemoglobin values ≥ 1g/dL including Hb values obtained after first study drug dose and before any rescue. Baseline is defined as hemoglobin measurements recorded on Day 1 of the first dose administered.

Number of participants with Hemoglobin > 10g/dL and a change from in hemoglobin values ≥ 1g/dL including Hb values obtained after first study drug dose and before any rescue. Baseline is defined as hemoglobin measurements recorded on Day 1 of the first dose administered.

The length of time in days that participants who were rescued received treatment. When applicable, participants were rescued for anemia. During the rescue, participants discontinued sotatercept and were unblinded to the study treatment. Participants who were rescued continued in the treatment phase of 200 days and a follow-up phase of 112 days after the treatment phase. Rescue is defined as the need for a blood transfusion or Erythropoiesis-stimulating agent (ESA) therapy.

Dose Cycle 1 is defined as the first 28 days of treatment for Dose Groups 0.3 mg/kg, 0.5 mg/kg, and 0.7 mg/kg and the first 14 days of treatment for Dose Group 0.7/0.4 mg/kg. End of the Treatment Period is defined as the day before the follow-up phase started. Baseline is defined as hemoglobin measurements recorded on Day 1 of the first dose administered.