November 5, 2010

New Stroke-Prevention Drug Is More Effective

(Ivanhoe Newswire) -- The recent approval of a drug may be a cost-effective way to prevent stroke in patients with an irregular heart rhythm. It may also offer patient's better health outcomes than the commonly prescribed and potentially risky blood thinner, warfain.

"Dabigatran is the first new drug in 20 years to be approved for stroke prevention in atrial fibrillation, and we wanted to see if it could be cost-effective even before it made its debut in the United States," cardiac electrophysiologist Mintu Turakhia, MD, MAS, a VA investigator and an instructor of medicine at Stanford was quoted as saying.

"We found that for the average patient "” 65 years and older with a risk of stroke "” this drug has the potential to be a cost-effective alternative to warfarin, depending on how it is priced," first author James Freeman, MD, MPH, a cardiology fellow at Stanford was quoted as saying.

The researchers hope their findings will help guide decisions by physicians, insurance payers and policy-makers about the drug, dabigatran, which the U.S. Food and Drug Administration approved on Oct. 19 for the prevention of stroke in patients with atrial fibrillation. "We now have sufficient efficacy and cost-effectiveness data to help inform policy on this drug in the United States," Turakhia said.

About 2.3 million Americans have atrial fibrillation, a disorder during which the heart's two upper chambers don't beat effectively. The irregular beating can cause pools of blood to form, and if a clot escapes from the heart and blocks an artery in the brain, a stroke occurs.

Atrial fibrillation is responsible for about 15 percent of the 700,000 strokes per year in the United States. Many patients are prescribed warfarin, an anticoagulant, to prevent stroke. Although warfarin is effective at reducing a patient's stroke risk, it is not a good treatment. The dosage has to be just right (too little and it could fail to prevent stroke, too much and it could lead to serious or fatal hemorrhage). Patients on the drug face constant blood testing and dose adjustment.

"Among my patients, I get asked about alternatives to warfarin a dozen times a week," said Turakhia, who specializes in the treatment and research of atrial fibrillation. "Many of them are just unhappy with the need for regular, often lifelong blood testing."

The research has focused on developing an effective replacement for warfarin, which has been in clinical use for 65 years. Dabigatran, an oral anti-clotting drug that requires no blood testing, emerged as one promising alternative. In a large, multicenter study published in the New England Journal of Medicine last year, the drug was about as effective as warfarin in preventing strokes but less likely to cause intracranial hemorrhages. Patients on the new drug did have a slightly increased risk of heart attack.

"It looked like we may have a therapy that is at least as effective and maybe even more effective than warfarin," said Freeman. But the question remained whether dabigatran would be cost-effective. "We were very interested in answering this question," he said.

In this study, researchers developed a mathematical model to compare the outcomes and costs of warfarin, dabigatran at low doses (110 mg twice a day), and high doses of dabigatran (150 mg twice a day). Dabigatran isn't priced for the U.S. market, but the researchers used pricing from the UK, where the drug is approved for prevention of venous thromboembolism. The cost per day is $13 for high doses, while warfarin costs just over $1 per day.

The model simulated 10,000 patients aged 65 and older with atrial fibrillation and risk factors for stroke. They found that high-dose dabigatran prevented 1,000 more intracranial hemorrhages and 600 more strokes than warfarin was calculated to prevent, though dabigatran resulted in 400 additional heart attacks. They also determined that total lifetime costs were $143,193 for warfarin, and $168,398 for high-dose dabigatran.

When taking into consideration adverse outcomes and costs, the researchers calculated that high-dose dabigatran yielded an additional 0.56 quality-adjusted-life-year "” a common metric that takes into account quality of life as well as length of survival "” when compared with conventional therapy with warfarin. Offering half a year of quality-adjusted life to a patient is "a fairly significant benefit," the researchers noted.

SOURCE: Annals of Internal Medicine, published online November 1, 2010