Studies led by Mount Sinai researchers reinforces potential benefits of new stroke-prevention drug
Pooled anaysis of SPORTIF III and V trials detailed at the American College of Cardiology annual meeting
(New Orleans, Louisiana – March 8) – Researchers at Mount Sinai School of Medicine announced an analysis of pooled data from two Phase III stroke prevention trials today at the American College of Cardiology (ACC) annual meeting in New Orleans, Louisiana. Pooled data demonstrated that ximelagatran, a new type of anti-clotting medication currently under FDA review, is as effective as current treatment warfarin for the prevention of stroke and systemic embolic events in men and women with nonvalvular atrial fibrillation (AF).
Although more men are affected with AF than women, the risk of AF-related strokes is greater among women. Warfarin is effective in preventing stroke but can be associated with bleeding, which occurs more often in women than men. Pooled data presented today on the SPORTIF (Stroke Prevention by ORal Thrombin Inhibitor in atrial Fibrillation) III and V studies are the first to compare ximelagatran in the men and women subgroup population.
This analysis on SPORTIF III and V compared the efficacy and safety of 5,075 men and 2,257 women treated with either ximelagatran or dose-adjusted warfarin, and showed that EXANTA is at least as effective as warfarin in preventing strokes and systemic embolic events. During 11,233 patient-years (mean 19 months) exposure, 72 primary events (2.2 percent per year treated with ximelagatran vs. 2.0 percent per year treated with warfarin) occurred in women and 112 primary events (1.4 percent per year treated with ximelagatran vs. 1.5 percent per year treated with warfarin) occurred in men. Ximelagatran was also associated with lower bleeding rates than warfarin, and the incidence of major and minor bleeding was greater among women than men (35.4 percent per year in women and 30.1 percent per year in men on ximelagatran vs. 44.8 percent per year in women vs. 36.3 percent per year in men on warfarin).
"Pooled analysis of this study reinforces the potential benefits of ximelagatran as a treatment option for men and women with AF," said Jonathan L. Halperin, M.D., Professor of Medicine and Director of Cardiology Clinical Services at the Zena and Michael A. Wiener Cardiovascular Institute and the Marie-Josée and Henry R. Kravis Center for Cardiovascular Health at The Mount Sinai Medical Center. "As only about half of all eligible patients receive optimal treatment due to complications associated with existing therapies, it is encouraging that ximelagatran may help protect patients at risk of thromboembolic events regardless of their gender."
As previously reported with results from SPORTIF III and V, an increase of liver enzymes (ALAT) was greater than three times the upper limit of normal in 6.1 percent of those treated with EXANTA vs. 0.8 percent treated with warfarin. However, nearly all enzyme changes occurred within the first six months of treatment with ximelagatran and decreased whether or not the drug was stopped.
The SPORTIF III and V studies, directed by investigators at Mount Sinai School of Medicine last year, represent the largest study program to date for stroke prevention in patients with AF. SPORTIF III (open-label) and V (double-blind) demonstrated that fixed oral-dose ximelagatran (36 mg twice daily) with no coagulation monitoring is as effective as well-controlled warfarin (dose-adjusted to a standard level of anticoagulation intensity, INR 2-3) in preventing strokes (ischemic or hemorrhagic) and systemic embolic events in patients with AF. AstraZeneca PLC, which is developing ximelagatran under the trade name EXANTA®, sponsored the research.
About Atrial Fibrillation
Atrial Fibrillation (AF) is a common irregular heartbeat that occurs when the two small upper chambers of the heart (known as the atria) beat rapidly and unpredictably, which sometimes allows blood to pool and clot. If a section of the blood clot travels to an artery in the brain, a stroke may result. AF affects more than two million Americans. Approximately 15 percent of all strokes occur in people with AF. Age, high blood pressure, diabetes and congestive heart failure further increase the risk of stroke in patients with AF. Patients with AF also tend to have more disabling first strokes compared to those without AF.
Stroke risk in patients with AF can be reduced by 62 percent using oral anticoagulant therapy such as warfarin. However, many eligible patients are not receiving oral anticoagulant therapy. Warfarin requires frequent monitoring, dosage adjustments to prevent excessive bleeding or inadequate anticoagulation, and can interact with many foods and medications.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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