Blood Thinner Causes BleedingMar 18, 2009 | Parker Waichman LLP U.S. Food and Drug Administration (FDA) staffers criticized a proposed new blood thinner called rivaroxaban, reported Dow Jones. The anti-coagulant rivaroxaban was created to prevent blood clots from forming and, while better than some of its competition at such prevention, said Dow Jones, the medication was found to increase bleeding in patients in clinical studies, the FDA revealed.
Rivaroxaban is joint venture between Bayer AG's health-care unit and Johnson & Johnson and is scheduled to undergo FDA panel review tomorrow, said Dow Jones. Rivaroxaban is sold in Europe under the brand name Xarelto and was approved there last year, but is awaiting FDA approval for short-term use in blood clot prevention following hip- or knee-replacement surgery, said Dow Jones, which noted that blood clots can be fatal if they travel to the lungs, heart, or brain. Blood clots typically form in the legs, it added.
The agency panel will vote on rivaroxaban’s so called risk-benefit profile, said Dow Jones, adding that if the findings are positive, the drug would likely be recommended for agency approval—Johnson and Johnson would then sell the drug in the U.S.; however, a negative result would likely lead to rejection. Although the final decision remains with the FDA, it generally acts on how the panel responds, reported Dow Jones, which pointed out that no oral blood thinner has been approved by the FDA since warfarin in 1954.
According to Reuters, FDA staff found that bleeding, cardiovascular events, and potential liver injury were linked to the anti-coagulant; its brand-name European version—Xarelto was found to cause bleeding “in significantly more patients” than enoxaparin, the current treatment used in the U.S. Enoxaparin is sold by Sanofi-Aventis SA under the brand name Lovenox. The clinical review stated that long-term safety data is needed to adequately evaluate rivaroxaban’s liver damage potential, said Reuters, which results from an increase in a liver enzyme that is indicative of liver damage, said Dow Jones.
Data submitted to the FDA concerning the drug included four major clinical studies that reviewed over 12,000 patients, said Dow Jones; the studies typically compared rivaroxaban to enoxaparin and revealed that bleeding which required medical intercession, while low, occurred at twice the rate as enoxaparin, a significant finding. The FDA found that in addition to bleeding risks being higher in the rivaroxaban group over the enoxaparin group, two rivaroxaban patients died of a fatal bleed during the clinical trial, said Dow Jones. There were no deaths in the enoxaparin group.
Enoxaparin is an injectable medication and one of the primary drugs used to prevent blood clots in certain surgery as well as for treatment of deep vein thrombosis (DVT) patients, said Dow Jones. DVT are dangerous, sometimes fatal, blood clots that form in a vein deep within the body, explained Dow Jones.
Rivaroxaban differs from other anti-coagulants—Bristol-Myers Squibb Company’s and Sanofi Aventis SA’s Plavix and aspirin—because existing treatments ensure blood platelets do not stick together said Dow Jones, whereas rivaroxaban targets Factor Xa, an enzyme involved in blood-clotting.