Registry Of Patients Treated With Protein C Concentrate (Human) In The United States and Europe: Interim Results
Authors: Manco-Johnson Marilyn J. , Knoebl Paul , Shapiro Amy D. , Finnerty Maureen , Yel Leman , Gelmont David 
Published: October 2019

Abstract

Background
Protein C (PC) is a naturally occurring, vitamin-K dependent anticoagulant produced by the liver. Deficiency of PC, which can be congenital or acquired, results in a hypercoagulable state. Patients with severe PC deficiency may manifest severe, often life-threatening, disseminated intravascular coagulation (DIC), purpura fulminans (PF), and/or thromboembolism. Highly purified protein C concentrate prepared from human donor plasma (Ceprotin; Baxter Healthcare Corporation, Westlake Village, CA) is an approved therapy for prevention and treatment of venous thrombosis and PF in patients with severe congenital PC deficiency (SCPCD) in the United States. It is indicated in patients with SCPCD for PF and coumarin-induced skin necrosis, and short-term prophylaxis in the European Union and other countries. Use of protein C concentrate (human) has been reported in patients with acquired PC deficiency. The Ceprotin Treatment Registry is a prospective, international, multi-center, open-label, non-interventional, observational study designed to examine the long-term safety and effectiveness of protein C concentrate (human) in the clinical setting. This is the first large, real-world assessment of the treatment of a rare disease with protein C concentrate (human). Here we report data from the first interim analysis in June 2013 covering a 3-year enrollment period.

Methods
Patients of any age who received, or were initiating/receiving protein C concentrate are included. The study duration is 5 years (3-year enrollment period plus 2 years of follow-up). All study visits/assessments are in accordance with standard of care, with protein C concentrate dose, dose frequency, duration and route of administration determined by the investigator. The study objectives are to determine the most common medical diagnoses associated with protein C concentrate treatment, protein C concentrate treatment regimens, and safety information based on all serious adverse events (SAEs) and rate of treatment-related AE. Other objectives include: an examination of the relationship between protein C concentrate treatment and outcomes in all registry participants, as well as various subgroups. Descriptive statistical analyses are used.

Results
At the time of data extraction, 34 patients were enrolled from 26 centers; 10 centers in the United States and 16 centers in Europe. Half of the patients were males. The primary diagnosis of PC deficiency was congenital in 25 patients (73.5%) and acquired in 9 patients (26.5%). The median age at diagnosis was 0.03 years (range 0–19.9). Mean plasma PC activity level was 9% (range 1–40.0). The most common (in ≥3 patients) thrombotic disease-associated conditions were PF (50.0%); blindness (44.1%); thromboembolic disease (41.2%), which included deep vein thrombosis, arterial thrombosis and DIC; stroke (32.4%), and renal dysfunction (8.8%). Of the 23 patients being treated with protein C concentrate, 15 were administered protein C concentrate intravenously, and 8 patients received protein C concentrate subcutaneously. The body weights of patients receiving subcutaneous treatment ranged from 10.0 kg to 57.9 kg. A total of 15 patients received an anticoagulant treatment in addition to protein C concentrate. Eight patients reported 23 SAEs, all of which were considered not related to treatment. Eighteen (52.9%) patients reported 72 AEs; only 1 of them, an episode of upper respiratory infection, was considered possibly treatment-related. In 18 patients in whom PC activity recovery was determined after protein C concentrate treatment, there were no patients documented with poor recovery. Protein C concentrate was used during 18 surgeries/invasive procedures and considered effective in all interventions for which data were available.

Conclusions
Data from the first interim analysis of the Ceprotin Treatment Registry demonstrate that patients with both congenital and acquired severe PC deficiency who are treated with protein C concentrate (human) have a low incidence of treatment related SAEs and AEs, and treatment with protein C concentrate appears to be effective when used during surgery/invasive procedures. Further patient follow up will shed light onto clinical treatment outcomes.

Disclosures:
Manco-Johnson: CSL Behring: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Novo Nordisk: Membership on an entity’s Board of Directors or advisory committees; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees; Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees; Bayer HealthCare: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Eisai: Research Funding. Knoebl:Novo Nordisk: Consultancy, Honoraria; Baxter: Consultancy, Honoraria. Shapiro:Cangene: Research Funding; Biogen Idec: Research Funding; Baxter BioScience: Research Funding; Bayer HealthCare: Research Funding. Finnerty:Baxter: Employment, Equity Ownership. Yel:Baxter: Employment, Equity Ownership. Gelmont:Baxter: Employment, Equity Ownership.