Apixaban, Xarelto deliver good results in studies

Pfizer and Bristol Myers Squibb's blood thinner apixaban beat aspirin in a study that may open the door to a multi-billion dollar-a-year market to prevent clots. Meanwhile, rival drug Xarelto made by Bayer delivered good results in dissolving potentially clots in the legs as well as preventing new ones--without causing either excessive bleeding or liver problems.

Apixaban, a Factor Xa inhibitor, was studied in the double-blind, randomized Averroes trial that recruited 5,600 patients with atrial fibrillation, a statement released by the European Society of Cardiology, which is conducting its meeting in Stockholm. Patients who took apixaban were 54 percent less likely to have a stroke or damaging clot than those who took aspirin in a study, as Bloomberg notes. Because of the positive results, a data monitoring committee earlier this summer recommended halting the trial. BMS owns the U.S. patent for apixaban and formed an alliance with Pfizer in 2007 to jointly develop and commercialize the drug, NASDAQ notes. 

About half of the 2.2 million Americans with atrial fibrillation don't take warfarin because of side effects or the need for constant monitoring. And these results leave "no competition for apixaban in the foreseeable future" for that group of patients and signal the drug could challenge warfarin, says lead investigator Stuart Connolly, of the Population Health Research Institute at McMaster University in Ontario, Canada, as quoted by Bloomberg. The companies may ask regulators to approve apixaban for irregular heartbeat patients on the basis of the Averroes trial alone, Seamus Fernandez, an analyst with Leerink Swann, writes in an investor note.

In the separate Aristotle study, investigators are evaluating apixaban against warfarin in patients suitable for warfarin, according to a statement.

Rival Bayer is also seeking to join the warfarin-replacement race. It has announced that Xarelto, being developed with Johnson & Johnson, was as effective as the standard treatment of injecting Sanofi-Aventis's Lovenox, followed by warfarin pills, Reuters reports. And Boehringer Ingelheim has a contestant  in the race--Pradaxa, which has demonstrated positive results. "Pradaxa has set a pretty high bar," says Deepak Bhatt, chief of cardiology at the VA Boston Healthcare System, adding that it has shown superiority, as pointed out by the Bloomberg. "That is really a tough threshold that has been set in terms of apixaban and Xarelto."

Analysts believe the market for products to replace warfarin, which was originally developed as rat poison, could eventually be worth between $10 billion as $20 billion annually.

- see the statement on the Averroes trial
- get more from Reuters
check out this report from Bloomberg 
- see this NASDAQ report
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