The drug being developed by Pfizer and Bristol-Myers Squibb is an anticoagulant; it works by preventing the formation of blood clots in veins by inhibiting an enzyme in the coagulation cascade.
Venous thromboembolism is the third most common cardiovascular illness; it includes deep vein thrombosis (blood clots in the legs) and pulmonary embolism (blood clots in the lungs). The blood clots that are formed can be fatal and the risk of them recurring is quite high.
Patients who underwent knee or hip replacement surgery have a higher risk of developing recurrent venous thromboembolism, as do some women on non-oral hormonal contraceptives, such as vaginal rings, implants and skin patches.
The randomized, double-blind study included 2,486 patients who had gone through 6 to 12 months of anticoagulant therapy prior to participating. The participants were randomly selected into three groups:
- The placebo group - 829 participants
- The 2.5 mg of apixaban group - 840 participants
- The 5 mg of apixaban group - 815 participants
The rate of recurrence and mortality was significantly lower in the groups taking apixaban compared to the placebo.
The placebo group had a rate of recurrence and mortality of 11.6% compared to 3.8% in the 2.5 mg apixaban group and 4.2 percent in the 5 mg group.
The drug did not cause much bleeding (as many blood thinners usually do), with only 0.2 percent in the 2.5 mg group and 0.1% in the 5.0 mg group experiencing major bleeding.
The drug is currently used in Europe, but not in the U.S where it is still awaiting approval. The main treatment for venous thromboembolism is Warfarin. More research is necessary to compare the effectiveness of Apixaban to this drug; this is expected soon.
The researchers concluded that apixaban could be used for extended treatment as it reduced the number of arterial thrombic events, reduced the risk of symptomatic recurrent fatal or non-fatal venous thromboembolism by around 80% and did not cause much major bleeding.
Dr. Giancarlo Agnelli, lead investigator of the study, said:
"Up to 10 percent of patients will experience a recurrent venous thromboembolism event after completing the currently recommended six-to-twelve-month treatment period, suggesting the need for additional prophylaxis. In the AMPLIFY-EXT trial, which added an additional year of treatment, ELIQUIS reduced the composite risk of recurrent venous thromboembolism and total mortality without an increase in major bleeding versus placebo."
About Eliquis (apixaban)Eliquis is an oral direct Factor Xa inhibitor, part of a new therapeutic class. It inhibits Factor Xa, a protein which plays a key role in the blood clotting process. Eliquis prevents blood clot formation and thrombin generation.
Apixaban was approved with the brand name Eliquis in Europe in May 2011; Eliquis is also the proposed brand name in the USA. It was approved last year in the European Union plus Iceland and Norway for the prevention of VTE (venous thromboembolic events) in adults who underwent elective knee or hip replacement surgery.
The European Commission approved Eliquis for the prevention of stroke and systemic embolism in adult patients with nonvalvular atrial fibrillation (NVAF) with one or more risk factors on November 20th, 2012.
On December 6th, 2012, Health Canada approved Eliquis for the prevention of stroke and systemic embolism in patients with atrial fibrillation.
Written by Joseph Nordqvist