"This study was a dose-finding study; it would be premature to assess the future of this drug in patients with acute coronary syndrome based on this trial, and the little bit of data that we have does not suggest the drug would provide a major benefit in patients who are already on contemporary therapy -- with the caveat that we need a larger trial to confirm or refute this," Gurm said.
Dr. Richard C. Becker, director of the Cardiovascular Thrombosis Center at Duke University Medical Center, said this study is another step in the search for an anti-clotting drug to replace warfarin for many patients. Warfarin is an effective drug, but requires constant monitoring to assure that patients are receiving a dose that is not too low, which is ineffective, or too high, which increases the risk of bleeding.
"The trends toward benefit with rivaroxaban, as a fixed-dose, direct and oral factor Xa inhibitor, provide a sound rationale to pursue a path of further investigation," Becker said.
The dose-related bleeding risk supports a strategy of lower doses than would be used for other potential indications for the drug, such as atrial fibrillation and venous thrombosis, he said.
"In the next several years, the field will have a wealth of information on antithrombotic therapies, providing a platform to determine optimal treatment in a wide range of patients with acute coronary syndrome," Becker said.
For more information on anticoagulants, visit the American Heart Association.
SOURCES: Jessica L. Mega, M.D., Cardiovascular Division, Brigham and Women's Hospital, Boston; Hitinder S. Gurm, M.D., director, inpatient services, division of cardiovascular medicine, University of Michigan Cardiovascular Center, Ann Arbor; Richard C. Becker, M.D., director, Cardiovascular Thrombosis Center, Duke University Medical Center, Durham, N.C.; June 17, 2009, The Lancet, online