This study consists of a 6-month open label Safety and Dose Confirmation Run-in Period (SRP), 6-month Randomized Control Period (RCP), and an additional 1-year open-label extension (OLE) period. To enter the Screening Period (Day -28 to Day -1) in the SRP or RCP, patients must have a clinical diagnosis of primary or secondary wAIHA due to an underlying autoimmune disorder, have failed at least 1 prior wAIHA treatment regimen, and have a Hgb level of ≥ 7 to < 10 g/dL with at least one sign or symptom of anemia. For the SRP only, patients with secondary wAIHA due to underlying lymphoproliferative disease may be eligible if they are receiving stable treatment.~All patients in the SRP or RCP are allowed to continue up to 2 failed wAIHA therapies throughout the 24-week study. On Day 1 of the SRP, patients receive obexelimab administered as subcutaneous (SC) injections. On Day 1 of the RCP, patients will be randomized in a ratio of 1:1 to receive either obexelimab or placebo administered as subcutaneous (SC) injections. Patients must return to the study site for the first 5 weeks and then every 2 weeks thereafter. Patients will undergo assessments for efficacy, safety, PK, PD, and immunogenicity during the 24-week SRP or RCP.~Following the 24-week SRP or RCP, patients will have the opportunity to receive obexelimab for up to 52 weeks in the Open Label Extension (OLE) Period.~Including screening and follow-up, the maximum duration of participation in this study for an individual patient is 81 weeks (i.e., 28-day screening, 24-week SRP or RCP, 52-week OLE, and an 8-week follow-up).
This study aims to examine the efficacy and safety of obexelimab in participants with Warm Autoimmune Hemolytic Anemia (wAIHA).