The authors conducted a formal indirect treatment comparison between Pradaxa® and rivaroxaban (according to the Markov model).

The analysis has to be viewed in light of the absence of a head-to-head study. The current interest in healtheconomic aspects of new treatments may encourage further scientific assessments to confirm the findings. Boehringer Ingelheim would endorse and support further investigation.

In the analysis the authors conclude:(1)

• Pradaxa® may provide a lower risk of stroke (RR=0.62; 95% CI 0.45-0.87) than rivaroxaban
• Pradaxa® may provide a lower risk of intracranial haemorrhage (ICH) (RR=0.38; 95% CI 0.21-0.67) than rivaroxaban

Looking at events per 100 patient-years, the model predicts that over a lifetime horizon, AF patients may experience(1)

• Considerably fewer ICH with Pradaxa® than with rivaroxaban (0.33 vs. 0.71)
• Less ischaemic strokes with Pradaxa® than with rivaroxaban (3.40 vs. 3.96)
• More quality-of-life-years with Pradaxa® than with rivaroxaban (6.17 vs. 6.01)

When assessing the costs of care, the analysis implies that patients treated with Pradaxa® incur lower costs of acute care and long term follow-up per patient, which, according to the authors, more than offset differences in drug costs.(1) The study shows consistent conclusions to previous analysis evaluating novel oral anticoagulant treatments in the Canadian market.(2)

The indirect comparison model is based on data from ROCKET AF(3) where patients were treated with rivaroxaban and Pradaxa® clinical event rates as observed in the safety-on-treatment population(4) in RE-LY®, a prospective, randomized, open-label trial with blinded endpoint evaluation, comparing two fixed doses of the oral direct thrombin inhibitor dabigatran etexilate (110mg and 150mg bid) each administered in a blinded manner, with open label warfarin.(5,6) The Pradaxa® data were adjusted mainly to reflect the higher level of warfarin control in RE-LY®) (the mean TTR (TTR = time in therapeutic range) was 64% in RELY® and 55% in ROCKET-AF) and simulated dosing corresponding to the approved Canadian treatment algorithm(7) for Pradaxa.

Dr Anuraag Kansal a research scientist in Health Economics, United BioSource Corporation, headquartered in the US said, "As more anticoagulation therapies become available, there is a need to understand the clinical and economic differences between new therapies. This research tells us that the benefits of dabigatran etexilate accrue steadily over time and that the novel oral anticoagulant continues to offer effective stroke protection for patients living with AF."

Stroke Prevention in Atrial Fibrillation
AF is the most common sustained heart rhythm condition(8), with one in four adults over the age of 409 developing the condition in their lifetime. People with AF are more likely to experience blood clots, which increases the risk of stroke by five-fold.(9,10) Up to three million people worldwide suffer strokes related to AF each year.(11-14) Strokes due to AF tend to be severe, with an increased likelihood of death (20%), and disability (60%).(15)

Ischaemic strokes are the most common type of AF-related stroke, accounting for 92% of strokes experienced by AF patients and frequently leading to severe debilitation.(16-20) Appropriate anticoagulation therapy can help to prevent many types of AF-related strokes and improve overall patient outcomes.(21)

Worldwide, AF is an extremely costly public health problem, with treatment costs equating to $6.65 billion in the US and over €6.2 billion across Europe each year.(21,22) Given AF-related strokes tend to be more severe, this results in higher direct medical patient costs annually.(23) The total societal burden of AF-related stroke reaches €13.5 billion per year in the European Union alone.(23)

About the dabigatran etexilate clinical trial programme
Boehringer Ingelheim's clinical trial programme to evaluate the efficacy and safety of dabigatran etexilate encompasses studies in:

• Primary prevention of venous thromboembolism (VTE) in patients undergoing elective total hip and knee replacement surgery
• Treatment of acute VTE
• Secondary prevention of VTE
• Stroke prevention in AF
• Prevention of thromboembolism after heart valve replacement.

About Boehringer Ingelheim
The Boehringer Ingelheim group is one of the world's 20 leading pharmaceutical companies. Headquartered in Ingelheim, Germany, it operates globally with 145 affiliates and more than 44,000 employees. Since it was founded in 1885, the family-owned company has been committed to researching, developing, manufacturing and marketing novel medications of high therapeutic value for human and veterinary medicine.

As a central element of its culture, Boehringer Ingelheim pledges to act socially responsible. Involvement in social projects, caring for employees and their families, and providing equal opportunities for all employees form the foundation of the global operations. Mutual cooperation and respect, as well as environmental protection and sustainability are intrinsic factors in all of Boehringer Ingelheim's endeavours.

In 2011, Boehringer Ingelheim achieved net sales of about 13.2 billion euro. R&D expenditure in the business area Prescription Medicines corresponds to 23.5% of its net sales.

1. Kansal A, et al. Dabigatran versus Rivaroxaban for the Prevention of Stroke and Systemic Embolism in Atrial Fibrillation in Canada: Comparative efficacy and cost-effectiveness. Thromb Haemost. 2012 Aug 17;108(4). [Epub ahead of print]
2. Canadian Agency for Drugs and Technology in Health. New Oral Anticoagulants for the Prevention of Thromboembolic Events in Patients with Atrial Fibrillation. April 9, 2012. Available at http://www.cadth.ca/media/pdf/NOAC_Therapeutic_Review_final_report.pdf
3. Patel MR, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med 2011;365(10):883-91.
4. Boehringer Ingelheim. Data on File.
5. Connolly SJ, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med 2009; 361:1139-51.
6. Connolly SJ, et al. Newly identified events in the RE-LY® trial. N Engl J Med 2010; 363(19):1875-6.
7. Boehringer Ingelheim Canada Ltd. PradaxTM Dabigatran Etexilate capsules product monograph.
8. Stewart S, et al. Cost of an emerging epidemic: an economic analysis of atrial fibrillation in the UK. Heart. 2004;90:286-92.
9. Lloyd-Jones DM, et al. Lifetime risk for development of atrial fibrillation: the Framingham Heart Study. Circulation. 2004;110:1042-6.
10. Fuster V, et al. ACC/AHA/ESC 2006 Guidelines for the management of patients with atrial fibrillation – executive summary. Circulation. 2006;114:700-52.
11. Global Atlas on Cardiovascular Disease Prevention and Control, World Health Organization in collaboration with the World Heart Federation and the World Stroke Organization 2011. Viewed May 2012 at http://www.world-heart-federation.org/fileadmin/user_upload/documents/Publications/Global_CVD_Atlas.pdf.
12. Atlas of Heart Disease and Stroke, World Health Organization, September 2004. Viewed Dec 2010 at http://www.who.int/cardiovascular_diseases/en/cvd_atlas_15_burden_stroke.pdf.
13. Wolf PA, et al. Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke. 1991;22:983-8.
14. Marini C, et al. Contribution of atrial fibrillation to incidence and outcome of ischaemic stroke: results from a population-based study. Stroke. 2005;36:1115-9.
15. Lin HJ, et al. Stroke severity in atrial fibrillation: the Framingham study. Stroke. 1996;27:1760-4.
16. Paolucci S, et al. Functional outcome of ischemic and hemorrhagic stroke patients after inpatient rehabilitation. Stroke. 2003;34:2861−5.
17. Petrea RE, et al. Gender differences in stroke incidence and poststroke disability in the Framingham Heart Study. Stroke. 2009;40:1032-7.
18. Meschia JF, et al. Genetic susceptibility to ischemic stroke. Nat Rev Neurol. 2011;7:369−78.
19. Andersen KK, et al. Hemorrhagic and ischemic strokes compared: stroke severity, mortality, and risk factors. Stroke. 2009; 40:2068−72.
20. Roger VL, et al. AHA Statistical Update. Heart Disease and Stroke Statistics—2011 Update. A Report From the American Heart Association. Circulation 2011; 123:e18−e209.
21. Coyne KS, et al. Assessing the direct costs of treating nonvalvular atrial fibrillation in the United States. Value Health 2006; 9:348-56.
22. Ringborg A, et al. Costs of atrial fibrillation in five European countries: results from the Euro Heart Survey on atrial fibrillation. Europace 2008; 10:403-11.
23. Brüggenjürgen B, et al. The impact of atrial fibrillation on the cost of stroke: the Berlin acute stroke study. Value Health 2007; 10:137-43.
24. Pradaxa®, European Summary of Product Characteristics, 2012.
25. Di Nisio M, et al. Direct thrombin inhibitors. N Engl J Med 2005; 353:1028-40.