Inclusion Criteria:

• Age ≥18 to 80 years
• Active autoimmune cytopenia
• Relapsed/refractory after standard of care therapy
• ECOG performance status 2 or lower

Laboratory parameters including the following:

• Absolute lymphocyte count (ALC) ≥0.5 × 109/L
• Absolute neutrophil count (ANC) ≥1.0 × 109/L
• Hemoglobin ≥6.5 g/dL
• Total bilirubin ≤1.5 × ULN unless related to Gilbert's syndrome
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.0 × ULN, unless attributable to hemolysis
• Estimated glomerular filtration rate (eGFR) based on the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula ≥30 mL/min/1.73m2

Exclusion Criteria:

• Pregnant or lactating women
• History of clinically significant disease, condition, or medical history that, in the opinion of the Investigator, would interfere with subject safety, study evaluations, and/or study procedures, would put the patient at undue risk or confound study results
• Evidence of active hepatitis B virus (HBV), hepatitis C virus (HCV), HIV, Epstein-Barr virus (EBV), or cytomegalovirus (CMV) infection
• Active or latent tuberculosis (TB) evidenced by a positive or indeterminate interferon gamma release assay (IGRA), unless the patient has documented previous completion of TB treatment and no current clinical indication of TB
• Presence of New York Heart Association class III or IV congestive heart
• Primary immunodeficiency or history of recurrent infections
• Previous treatment with a BCMA-targeted therapy
• Receipt of an investigational therapy within 30 days or 5 drug-elimination half-lives (whichever is longer) prior to Day 1
• History of solid organ transplant
• Planned major surgery in the timeframe of the dosing period