Edoxaban - Next Generation Oral Anticoagulant To Help Prevent Stroke In Patients With Atrial Fibrillation

Main Category: Stroke
Also Included In: Cardiovascular / Cardiology;  Heart Disease;  Clinical Trials / Drug Trials
Article Date: 03 Sep 2009 - 1:00 PDT

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Edoxaban, an oral factor Xa inhibitor, is currently being investigated in the pivotal phase III study ENGAGE AF-TIMI 48 (Effective aNticoaGulation with factor xA next GEneration in Atrial Fibrillation) as a potential new treatment for stroke prevention in patients with atrial fibrillation (AF). The new drug, developed solely by DAIICHI SANKYO, could offer substantial improvements over the current standard of care in thromboembolic disease.

In Europe, approximately 4.5 million people suffer from AF. "Without anticoagulation treatment these patients have a considerably high risk of having a stroke, approximately five times higher than that of the average population" said John Camm, Professor of Clinical Cardiology, St. George's University of London, UK, during a press conference organised by DAIICHI SANKYO EUROPE.

Anticoagulants interfere with the coagulation system resulting in a decreased tendency for the formation of blood clots, and are used to treat and prevent thromboembolic events. Existing anticoagulants, like heparin and vitamin K antagonists have been shown to be effective.1 However the use of these treatments, particularly vitamin K antagonists, is limited by the requirement for close monitoring, drug-to-drug and food-to-drug interactions, as well as a considerable risk of bleeding.1

"There is a definite need for new and improved oral anticoagulants for stroke prevention in patients with atrial fibrillation", commented Jeffrey I. Weitz, MD, FACP, FRCP, Professor of Medicine and Biochemistry, McMaster University and Director of the Henderson Research Centre, Ontario, Canada. "Edoxaban could offer significant improvements over the current standard of care."

A comprehensive phase I and phase II study programme for edoxaban has already indicated dose-dependent anticoagulation over a range of doses, with no significant dose-related increase in bleeding:

- Edoxaban has a safety and tolerability profile similar to that of warfarin in patients with non-valvular atrial fibrillation.2 The incidence of major and clinically relevant non-major bleeding events reported in the 30 mg and 60 mg once daily edoxaban treatment groups was similar to, or better than, those in the warfarin treated group. These doses of edoxaban are being compared with warfarin in the ongoing ENGAGE AF-TIMI 48 trial.

- Edoxaban demonstrated significant dose-dependent reductions in venous thromboembolism after total knee or hip replacement surgery.3,4

These data are encouraging for patients and support edoxaban's potential to significantly streamline anticoagulation management, while providing effective protection against severe thromboembolic events like stroke. Results from the phase II studies are important because they have been used to establish the optimal dosing regimen to pursue in the phase III clinical trial ENGAGE AF-TIMI 48.

Experts are anticipating the outcome of this phase III study. "This study is intended to show that atrial fibrillation patients can be treated simply, effectively and safely with once-daily administration of the factor Xa inhibitor edoxaban" said Robert Giugliano, MD, SM, FACC, Senior Investigator, TIMI-Study Group, Associate Physician and Assistant Professor in Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA.

ENGAGE AF-TIMI 48 compares two different doses of edoxaban with warfarin in patients with AF. Approximately 16,500 patients will be enrolled in this double-blind trial from 1,400 clinical sites worldwide. Patients will be assigned, in a double-blind, double-dummy fashion, to one of three treatment groups: 30 mg edoxaban once daily, 60 mg edoxaban once daily or warfarin. Edoxaban will be given in fixed doses without coagulation monitoring. In contrast, the dose of warfarin will be adjusted to maintain the international normalised ratio (INR) between 2.0 and 3.0. The primary efficacy endpoint is stroke and systemic events, while the primary safety endpoint is the occurrence of major and clinically relevant non-major bleeding events, using the sensitive ISTH (International Society on Thrombosis and Haemostasis) scale. The expected median treatment duration in the study is 24 months; the sponsor, DAIICHI SANKYO, expects the study to conclude in the first half of 2012.

Notes

- Phase III trials will also be conducted to assess edoxaban for the prevention of venous thromboembolism (VTE) after hip or knee replacement surgery in Asian markets.

- Factor Xa is a key enzyme in blood coagulation. When factor Xa is inhibited, blood clot formation is attenuated, thereby minimising the possibility of thromboembolic events, like stroke.

References

1. Weitz JI, Bates SM. New anticoagulants. J Thromb Haemost. 2005; 3: 1843-53.

2. Weitz JI, Connolly SJ, Kunitada S, Jin J, Patel I. Randomised, parallel group, multicentre, multinational study evaluating safety of DU-176b compared with warfarin in subjects with non-valvular atrial fibrillation. ASH Annual Meeting 2008; 112: Abstract 33.

3. Fuji T, Fujita S, Tachibana S, Kawai Y. Randomised, double blind, multi-dose efficacy, safety and biomarker study of the oral factor Xa inhibitor DU-176b compared with placebo for prevention of venous thromboembolism in patients after total knee arthroplasty. ASH Annual Meeting 2008; 112: Abstract 34.

4. Raskob G, Cohen A, Eriksson B et al. Randomised, double blind, multi dose trial of the oral factor Xa inhibitor DU-176b versus LMW heparin (Dalteparin) for prevention of venous thromboembolism after total hip replacement. European Heart Journal. 2008; 29: Abstract supplement 609.

Source
DAIICHI SANKYO

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