Safety, Tolerability, and Clinical Pharmacology of ANX009, an Inhibitory Antibody Fab Fragment Against C1q, Administered Subcutaneously to Healthy Volunteers

Certain autoantibodies that bind to tissue antigens or that deposit in tissues as a component of immune complexes can activate the classical complement cascade, leading to inflammation and tissue damage. As the initiating molecule of the classical complement cascade, C1q is an attractive target for preventing complement activation and its multiple tissue-damaging effects. ANX009 is an antigen binding fragment (Fab) of a humanized antibody against C1q that inhibits C1q substrate interactions and fully blocks activation of all downstream classical complement components. While inhibiting the classical cascade, ANX009 leaves the lectin and alternative complement pathways intact for their normal immune functions. ANX009 is formulated for subcutaneous (SC) administration and is designed for treatment of blood-based and vascular antibody-mediated autoimmune diseases, such as autoimmune hemolytic anemia (AIHA) and lupus nephritis, where complement activation is a key component of disease pathology.