The purpose of this study is to evaluate the ability of peginesatide (AF37702) to increase and maintain increased hemoglobin levels in participants with chronic kidney disease (CKD) (either not on dialysis, receiving regular hemodialysis or peritoneal dialysis, or following renal transplant) with confirmed antibody-mediated pure red cell aplasia (PRCA).

The drug being tested in this study was peginesatide. Peginesatide injection was tested to investigate the efficacy and safety in the treatment of anemia caused by antibody-mediated pure red cell aplasia in participants with chronic kidney disease.

The study enrolled 22 patients. All the participants enrolled into the study received:

• Peginesatide 0.5 mg/kg subcutaneous (SC) injection

The participants received a starting dose of 0.05 mg/kg (every 4 weeks) followed by 0.1 mg/kg dose, based on the assessment of the dose response in the initial group of 5 participants. The frequency of each injection and the dose adjusted based on the participant's hemoglobin response and the ability to maintain a hemoglobin level in the range of 10.0-12.0 g/dL.

This multi-center trial was conducted in Europe. The overall time to participate in this study was 10 years and 7 months approximately. Participants made multiple visits to the clinic until the projected end of treatment period, which was 31-Oct-2016.

Inclusion Criteria:

• Participants who have confirmed antibody-mediated Pure red cell aplasia (PRCA) are potentially eligible for enrollment into this study.
• Participants must be ≥ 18 years old at the time of consent.
• Erythropoiesis stimulating agents (ESAs) must be discontinued for a minimum of 1 month prior to screening.
• Participant requires periodic transfusions to maintain hemoglobin.
• Hemoglobin < 10 g/dL for at least 2 measurements or participant has received a transfusion within the past 4 weeks to achieve a hemoglobin > 10 g/dL.
• Confirmation that an anti-erythropoietin antibody sample was obtained for analysis by the central reference laboratory within 1 month prior to baseline.
• Participants can either be participants with chronic kidney disease not yet requiring renal replacement therapy (participants not on dialysis), those on regular hemodialysis or peritoneal dialysis, or following a renal transplant.
• Participants may or may not have previously been treated with immunosuppressive therapy.
• Pre-menopausal females (with the exception of those who are surgically sterile) must have a negative pregnancy test at screening.
• Written informed consent must be obtained.

Exclusion Criteria:

• Participants already successfully on another erythropoietic agent.
• Abnormal bone marrow findings consistent with the diagnosis of myelodysplasia, a myeloproliferative disorder, hematologic malignancy or evidence of metastatic infiltration.
• Poorly controlled hypertension.
• Previous exposure to any investigational agent within 4 weeks prior to administration of study drug or planned receipt during the study period.
• High likelihood of early withdrawal or interruption of the study.
• Participants who refuse to give informed consent.
• Women who are pregnant, lactating or not using a medically approved birth control.
• Life expectancy <12 months.