Key Inclusion Criteria:  Diagnosed with primary or secondary WAIHA at least 6 weeks prior to Screening. Failed or have not tolerated at least one prior WAIHA treatment regimen, for example, corticosteroids, rituximab, azathioprine, cyclophosphamide, cyclosporine, mycophenolate mofetil, danazol, or vincristine. Hemoglobin < 10 g/dL and ≥ 6 g/dL at Screening. Positive direct antiglobulin test (Coombs) (IgG positive who are positive or negative for the presence of complement C3) at Screening.  Evidence of active hemolysis including any one of the below:  LDH > upper limit of normal (ULN) or Haptoglobin < lower limit of normal or Indirect bilirubin > ULN Total IgG > 500 mg/dL at Screening Platelet count ≥ 75 x 10^9/liter (L) Absolute neutrophil count greater than 1.0 x 10^9/L  Key Exclusion Criteria:  Participants with Evan's syndrome. Human immunodeficiency virus (HIV) infection (positive HIV 1 or HIV 2 antibody test). Positive hepatitis B surface antigen or hepatitis C antibody test. Inability to travel to the clinic for specified visits during the Primary Treatment Period or fulfill the logistical requirements of study intervention administration.