Amrecibart

**Semantic type:** Amino Acid, Peptide, or Protein|Immunologic Factor|Pharmacologic Substance

**Definition:** An anti-factor XI (FXI) antibody, with potential anti-thrombotic activity. Upon administration, amrecibart targets and binds to the apple 2 (A2) domain of FXI and activated FXI (FXIa), thereby preventing the intrinsic pathway-triggered FXI activation. This prolongs the activated partial thromboplastin time (aPTT) and reduces platelet and fibrin accumulation. This results in the inhibition of contact activation-initiated blood coagulation and prevents thrombus formation. FXI contributes to thrombotic disease while playing a limited role in normal hemostasis. Activation of FXI is essential for thrombus growth and stabilization.

**Synonyms:** - AMRECIBART - Anti-FXI Monoclonal Antibody REGN9933 - Anti-factor XI Antibody REGN9933 - Anti-factor XI Monoclonal Antibody REGN9933 - REGN 9933 - REGN-9933 - REGN9933