SR604

SR604 is a humanized chimeric monoclonal antibody developed by Equilibra Bioscience as a novel therapeutic for congenital factor deficiencies, specifically hemophilia A and hemophilia B. It selectively inhibits the anticoagulant activity of human activated protein C (APC) without interfering with APC's cytoprotective or endothelial barrier functions. This targeted mechanism allows for rebalancing coagulation in patients with factor VIII or IX deficiency, providing both prophylactic and therapeutic benefits. Preclinical studies demonstrated that SR604 has approximately 60 times greater affinity for APC than its murine precursor HAPC1573, resulting in effective hemostasis in animal models of hemophilia. The drug exhibits high bioavailability and an extended half-life when administered subcutaneously, supporting infrequent dosing regimens. Currently, SR604 is being evaluated in Phase 1 clinical trials for safety, tolerability, pharmacokinetics, pharmacodynamics, and efficacy in both healthy volunteers and patients with hemophilia A or B[1][2][4][5][6].

Other names

HAPC1573 (murine precursor)Humab-14 (intermediate humanized variant)