Blood clots are a serious condition that can suddenly escalate to a life-threatening situation. The current standard of treatment in cases of blood clots or strokes is to give patients warfarin, a well-known blood thinning agent marketed as Coumadin, Jantoven, Marevan, Lawarin, Waran, and Warfant. Yet, the side effects of warfarin include a significantly increased risk of bleeding, which in and of itself can be deadly to a patient. Eliquis, which is an oral drug jointly developed by Bristol-Myers Squibb and Pfizer, was approved in December to treat patients with a risk of stroke or serious blood clots and who have atrial fibrillation not caused by a heart valve issue.

Both companies have just released data that the drug can is not only as good as the current standard of care, but also doesn't cause the serious bleeding side effects that warfarin does. The companies completed a Phase III clinical trial in 5,395 patients with venous thromboembolism (VTE), a condition that can includes deep vein thrombosis (DVT), or a blood clot developing inside of a vein, and pulmonary embolism (PE), which is a blood clot blocking one or more blood vessels to the lungs, both of which can be deadly.

The trial showed that Eliquis was superior to warfarin in reducing bleeding, lowering the risk of such a side effect by 69 percent. There was also a 50-percent reduction in a category called "clinically relevant non-major bleeding." Patients who entered the study with either a deep vein thrombosis or a pulmonary embolism had the same chance of reduced bleeding with the drug, while maintaining its ability to thin the blood and dissolve blood clots. This means that the safety profile for the drug was better than warfarin.

"The study results showed that apixaban, as a single-agent, has comparable efficacy with significantly fewer major bleeding events with respect to the standard of care. These results complement the previously published results for the AMPLIFY-EXT study," said Dr. Giancarlo Agnelli, professor of internal medicine at the University of Perugia and lead investigator of the study, in a press statement. "Together these studies represent exciting data in the field of VTE treatment and indicate that apixaban may offer an important potential alternative in both acute and extended anticoagulation therapy for VTE patients."

The condition affects 900,000 Americans each year and over one million people in Europe, so having a safer drug, which is just as effective as the current treatment yet presents fewer risks, is welcomed.

Eliquis, also known as Apixaban, is an anticoagulant small molecule drug that blocks the blood clotting Factor Xa. The drug has only been approved in Europe for preventing blood clots in patients who have had elective knee or hip replacement.

Warfarin, the current standard of care, has been used for decades, but the risk of bleeding is always present. Many doctors are wary of switching to the new class of blood thinning agents because their effect is not easily reversible, like warfarin. This is important because if an emergency surgery needs to take place, the doctors don't want a chance that the patient will bleed out, and want the power to easily reverse a blood thinner's action. Warfarin also requires significant patient monitoring because of the possible adverse effects of the drug.

The companies plan to jointly apply to the Food and Drug Administration to have the drug approved for initial- and long-term treatment of VTE as well as extended prevention of VTE in patients who have the risk of reoccurrence.

Source: Agnelli G, Buller H, Cohen A, et al. Oral Apixaban for the Treatment of Acute Venous Thromboembolism. New England Journal of Medicine. 2013.