Xarelto (rivaroxaban): New FDA Indication for DVT, PE
The U.S. Food and Drug Administration (FDA) approved Bayer's Xarelto (rivaroxaban) for a new indication for treating deep vein thrombosis (DVT) or pulmonary embolism (PE), and for long-term prophylaxis of recurrent DVT and PE.
Xarelto already had FDA approval for prevention of DVTs and PEs after knee or hip replacement surgery (July 2011), and for stroke prevention in in people with non-valvular atrial fibrillation (November 2011).
Xarelto got expedited approval under FDA's priority review program, a six-month review for drugs that represent major advances in treatment (as was considered in this case) or that offer treatment where none exists.
“Xarelto is the first oral anti-clotting drug approved to treat and reduce the recurrence of blood clots since the approval of warfarin nearly 60 years ago,” said Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research in a press release.
Xarelto's safety and effectiveness were evaluated in three clinical studies totaling 9,478 patients with DVT or PE. Patients were randomly assigned to receive either Xarelto, enoxaparin and warfarin, or placebo. The studies measured recurrent DVT, PE or death after randomization.
Results showed Xarelto worked as well as enoxaparin with warfarin for treating DVT and PE. About 2% of people treated with Xarelto vs. 1.8% - 3% of those treated with warfarin / enoxaparin had a recurrent DVT or PE. A third study showed prolonged Xarelto treatment reduced the risk of recurrent DVT and PE. About 1.3% of people treated with Xarelto compared with 7% percent of patients receiving placebo experienced a recurrent DVT or PE.
Unlike warfarin, Xarelto does not require initial "overlap" or "bridging" with heparin / enoxaparin, and also does not require blood level monitoring, simplifying treatment. These benefits come at a price: Xarelto costs $3,000 a year, as compared to about $200 for warfarin.
Xarelto can cause major bleeding, but thus far, observed rates of major bleeding events caused by rivaroxaban have not exceeded the rates of major bleeding caused by warfarin, and may well be lower (1% compared to 1.7% overall). Prothrombin complex concentrate seems to reverse the effects of Xarelto, and could be used as an antidote (similar to its use for warfarin-induced bleeding). Postmarketing studies will be conducted to discover Xarelto's bleeding "real world" risk, outside of clinical trials.