FDA staff recommends limited use of Daiichi's blood thinner

(Reuters) - U.S. Food and Drug Administration staff reviewers recommended approval of a 60 mg dose of Daiichi Sankyo Co's blood thinner for some atrial fibrillation patients, but suggested limiting its use to those with abnormal kidney function. The drug, edoxaban, is a once-daily anticoagulant that inhibits Factor Xa, a protein that plays a central role in blood-clotting. Edoxaban is being considered for use in some patients with atrial fibrillation, characterized by a rapid and irregular heartbeat that can cause strokes. While the 60 mg dose of the drug was markedly superior to widely-used anticoagulant warfarin in mildly renally impaired patients, it was almost significantly worse in patients with normal renal function, the reviewers said. "Although the ... overall findings support effectiveness, efficacy outcomes by baseline renal function have potential implications for approval or labeling." The report comes two days ahead of a meeting of independent experts to discuss the drug and recommend whether it should be approved. While the FDA is not obligated to follow the recommendations of its advisory panels, it typically does so. Although edoxaban is as effective as warfarin, two other currently approved drugs are more effective than warfarin, agency staff noted. (http://1.usa.gov/1wHOZW8) "It's obvious to question whether edoxaban could be inferior to other approved therapies and whether this constitutes a reason not to approve." Data from a late-stage trial of edoxaban released a year ago also showed it was safer than warfarin in preventing strokes and certain blood clots, and associated with less major bleeding, the biggest risk with blood thinners. (http://reut.rs/1FSHM8z) Warfarin, which has been on the market for over half a century, is effective in preventing strokes but its use necessitates blood level monitoring, dose adjustments and dietary restrictions. If approved, edoxaban, will compete with other drugs in its class, including Xarelto, sold by Bayer AG and Johnson & Johnson; and Eliquis, sold by Bristol-Myers Squibb Co and Pfizer Inc. It will also compete with Pradaxa, made by privately held Boehringer Ingelheim. While Edoxaban and Xarelto are once-daily pills, Eliquis and Pradaxa are taken twice a day. Savaysa, which is the proposed brand name for edoxaban in the United States, is also undergoing regulatory review for the treatment of venous thromboembolism (VTE). Launched as Lixiana since 2011 in Japan, it is used in the prevention of VTE after major orthopedic surgery. (Reporting by Natalie Grover in Bangalore and Toni Clarke in Washington; Editing by Simon Jennings)