An Open-label Study of Povetacicept in Participants With Autoimmune Cytopenias (RUBY-4)

Who can take part

• Indication-specific Criteria; Immune Thrombocytopenia (ITP); Documented persistent or chronic primary ITP of at least 12 weeks duration from diagnosis to Cycle 1 Day 1; History of failure or relapse to at least 2 treatment regimens for ITP; History of exposure to a TPO-RA unless otherwise contraindicated or unavailable; Documented history of platelets <30 × 10\^9/L; Warm Autoimmune Hemolytic Anemia (wAIHA); Diagnosis of primary wAIHA of at least 12 weeks duration documented with a current or prior positive direct antiglobulin test (DAT) for anti-IgG (±C3d); Documented history of anemia with hemoglobin ≤10 g/dL; At least one of the following: (i) haptoglobin < lower limit of normal (LLN) (ii) indirect bilirubin > upper limit of normal (ULN) (iii) lactate dehydrogenase>ULN; History of failure or relapse to at least 2 treatment regimens for wAIHA; Cold Agglutinin Disease (CAD); Diagnosis of primary CAD of at least 12 weeks duration with all of the following: (i) chronic hemolysis (ii) polyspecific DAT positive (iii) monospecific DAT strongly positive for C3d (iv) cold agglutinin titer ≥64 at 4°C (v) IgG DAT ≤1+ (vi) no overt malignant disease; Documented history of anemia with hemoglobin ≤10 g/dL; Evidence of hemolysis during screening: (i) indirect bilirubin; >ULN and (ii) lactate dehydrogenase>ULN or haptoglobin <LLN; History of failure or relapse to at least 1 treatment regimen for CAD
• (All indications) If receiving protocol-specified standard-of-care medications, doses must be stable for protocol-specified durations

Who cannot take part

• Treatment with any of the following within the noted period prior to study entry; rituximab: <12 weeks; IVIg: <4 weeks; sutimlimab, any use after initiation of screening is exclusionary; plasmapheresis, plasma exchange, or double-filtration plasmapheresis: <8 weeks; transfusions with blood, blood products or other rescue medications: <2 weeks; splenectomy: <12 weeks; other immunomodulatory or investigational agents, except for investigational agents for COVID-19 that have been granted emergency use authorization or approved by the applicable national health authority: <5 half-lives and requires agreement of the Medical Monitor
• Recent serious or ongoing infection; risk or history of serious infection Other protocol defined Inclusion/Exclusion criteria may apply
• Secondary AIHA, CAD, or ITP