Centessa Pharmaceuticals Announces Dosing of First Subject in Registrational PRESent-3 Study Evaluating SerpinPC for the Treatment of Hemophilia B with Inhibitors

BOSTON and LONDON, Oct. 31, 2023 (GLOBE NEWSWIRE) -- Centessa Pharmaceuticals plc (Nasdaq: CNTA), a clinical-stage pharmaceutical company focused on discovering and developing medicines that are transformational for patients, today 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. The Company began dosing subjects in the registrational PRESent-2 study for the treatment of hemophilia B without inhibitors in July 2023. SerpinPC is an investigational subcutaneously administered novel inhibitor of activated protein C (APC) being developed as a potential treatment for hemophilia B, with or without inhibitors.

“We are excited to be further evaluating the potential of SerpinPC’s novel mechanism of action in individuals living with hemophilia B with inhibitors, where there are limited treatment options,” said Antoine Yver MD MSc, Chairman of Development of Centessa.

The PRESent-3 study (AP-0103) is a Phase 2b, global, open-label study to investigate the efficacy and safety of subcutaneous dosing of 1.2 mg/kg of SerpinPC every 2 weeks in approximately 12 adult (aged 18 to ≤65 years) or adolescent (aged ≥12 to <18 years) male subjects with hemophilia B (with inhibitors). Subjects must have undergone a minimum period of prospective observation (at least 12 weeks) under their current therapy before switching to SerpinPC treatment. The primary efficacy endpoint for the study is the rate of treated bleeds (expressed as an annualized bleeding rate (ABR)) in the observation period compared to the first 24 weeks treated with SerpinPC.

About 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 interventional studies include PRESent-2 (moderately severe to severe hemophilia B without inhibitors, and severe hemophilia A with or without inhibitors) and PRESent-3 (hemophilia B with inhibitors). Additional information on the trials can be accessed at www.clinicaltrials.gov (NCT05605678, NCT05789524, NCT05789537). The U.S. Food and Drug Administration (FDA) has granted Fast Track designation to SerpinPC for the treatment of hemophilia B, with or without inhibitors. SerpinPC is an investigational agent that has not been approved by the FDA or any other regulatory authority.