Centessa Pharmaceuticals plc announced the dosing of the first subject in its registrational Present-3 study of SerpinPC for the treatment of hemophilia B with inhibitors. The dosing phase of Present-3 follows a minimum 12-week observation period during which prospective baseline data of the subject's disease status under their current therapy are collected to support regulatory review of the benefit and risk profile of SerpinPC. SerpinPC is a subcutaneously administered novel inhibitor of APC being developed as a potential treatment for hemophilia, regardless of severity or inhibitor status, and which may also be developed to prevent bleeding associated with other bleeding disorders.

The registrational program for SerpinPC in hemophilia B includes a set of clinical studies with multiple components. Present-5 is an observational feeder study to collect prospective observational data for minimum defined periods before switching to dosing subjects in the interventional studies. The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to SerpinPC for the treatmentof hemophilia B, with or without inhibitors.

SerpinPC is an investigational agent that has not been approved by the FDA or any other regulatory authority.