A Study to Evaluate the Efficacy and Safety of Pegcetacoplan in Patients With Cold Agglutinin Disease (CAD)

The purpose of the study is to determine the efficacy of pegcetacoplan administration compared to placebo in increasing hemoglobin (Hgb) level from baseline and avoiding transfusion in participants with primary cold agglutinin disease (CAD).

This is a blind (actual treatment not disclosed to Investigator or participant) study to study pegcetacoplan in people with cold agglutinin disease. The study will consist of a 4-week screening period where selected tests will be conducted to ensure that the patient is eligible to participate in the study, followed by Part A, a 24-week blinded treatment period where the participants will receive either pegcetacoplan or a placebo treatment, looking like pegcetacoplan but with no effect. After this period, the participants will move into Part B, a 24-week period where they will all receive pegcetacoplan. Part C is a 48-week maintenance period with pegcetacoplan for all participants. After the end of treatment participants will undergo a safety follow visit about 8 weeks after last dose. All eligible study participants will receive pegcetacoplan or placebo treatment, administered via subcutaneous infusion twice a week at home. The subcutaneous infusion requires two small needles to be inserted into the fatty layer of tissue under the skin and the investigational medication will flow into the body. Study participants and/or caregivers will be trained on home administration of pegcetacoplan.