In order to bring you the best possible user experience, this site uses Javascript. If you are seeing this message, it is likely that the Javascript option in your browser is disabled. For optimal viewing of this site, please ensure that Javascript is enabled for your browser.
Did you know that your browser is out of date? To get the best experience using our website we recommend that you upgrade to a newer version. Learn more.

TAO Results End Hope for Otamixaban in NSTE-ACS

Risk of major or minor bleeding was approximately doubled with otamixaban

Otamixaban significantly increased bleeding without reducing mortality or new heart attacks
Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Venous Thromboembolism

Amsterdam, The Netherlands , Sunday 1 September 2013  – The investigational anticoagulant otamixaban significantly increased bleeding without reducing mortality or new heart attacks compared to currently recommended therapy among patients with non–ST-segment elevation acute coronary syndromes (NSTE-ACS) who were scheduled for an early invasive strategy,  according to results of the Treatment of Acute Coronary Syndromes with Otamixaban (TAO) trial.
The TAO study failed to meet its primary endpoint showing superiority of otamixaban,  an injectable factor Xa inhibitor, over a combination of unfractionated heparin (UFH) and eptifibatide in moderate- to high-risk  NSTE-ACS patients scheduled to undergo angiography and potentially percutaneous coronary intervention (PCI) within 3 days of randomization.

“The risk of major or minor bleeding was approximately doubled with otamixaban across all patient subgroups, and a lower dose did not achieve better results,” said the study’s lead investigator Philippe Gabriel Steg, MD, from the Hôpital Bichat, Assistance Publique - Hôpitaux de Paris.

The findings “suggest a narrow therapeutic window for acute injectable Xa inhibition in the setting of ACS treated with modern antiplatelet therapy and routine early intervention, and that raising the intensity of anticoagulation via this mechanism will not achieve a superior efficacy/safety balance in ACS in the modern era of intervention,” said Professor Steg.

In June, the developer, Sanofi, announced its decision to discontinue the investigational program with the drug “due to efficacy lower than expected”.

The multicenter, phase 3 TAO study randomized 13,229 patients to either standard treatment consisting of UFH plus downstream eptifibatide (started only for PCI patients and discontinued 18 to 24 h after PCI ) or otamixaban (0.08 mg/kg intravenous bolus at randomization then 0.100 or 0.140 mg/kg per hour intravenous infusion).  UFH and otamixaban (and their placebos) were started and stopped usually at the end of PCI unless patients required continued anticoagulation for a medical reason.

In addition to the study medication all patients received both aspirin and an oral adenosine diphosphate receptor antagonist.

Rates for the primary outcome, a composite of all-cause death or new myocardial infarction from randomization to day 7, were not significantly different between the two groups (5.5% with otamixaban vs 5.7% with controls, adjusted relative risk 0.99, P =.93).

However, the primary safety outcome, the rate of major or minor bleeding according to Thrombolysis in Myocardial Infarction (TIMI) criteria  through day 7 was more than doubled with otamixaban (3.1% vs 1.5%, relative risk 2.13, P<.001).
Unfractionated heparin (UFH), particularly when combined with a glycoprotein IIb/IIIa inhibitor (GPI) such as eptifibatide at the time of percutaneous coronary intervention (PCI), “remains an effective and widely used therapy, and its use is supported by US and European guidelines,” said Professor Steg.

“However, UFH has limitations, such as a narrow therapeutic window, a somewhat unpredictable anticoagulant response, and activation of the PF4 platelet receptor,” he explained.

Theoretically, otamixaban, seemed an attractive anticoagulant for this patient population because it is an injectable agent with rapid onset and offset, modest renal elimination, and predictable anticoagulant effect that obviates the need for monitoring.

Although a previous phase 2 trial (SEPIA-ACS1 TIMI 42) had suggested a clinical benefit of otamixaban, it was a dose-ranging trial, with an overall low event rate, making risk estimates less accurate. The dosing of eptifibatide was also slightly different.


This press release accompanies both a presentation and an ESC press conference at the ESC Congress 2013. Edited by the ESC from material supplied by the investigators themselves, this press release does not necessarily reflect the opinion of the European Society of Cardiology. The content of the press release has been approved by the presenter.
More information on the ESC Press Conference page: Hot Line I: Late Breaking Trials on Thrombosis

Notes to editor

About the European Society of Cardiology
The European Society of Cardiology (ESC) represents more than 80 000 cardiology professionals across Europe and the Mediterranean. Its mission is to reduce the burden of cardiovascular disease in Europe.
About ESC Congress 2013
The ESC Congress is currently the world’s premier conference on the science, management and prevention of cardiovascular disease.  The spotlight of this year's event is "The Heart Interacting with Systemic Organs".  ESC Congress 2013 takes place from 31 August to 4 September at the RAI centre in Amsterdam, Netherlands. More information on ESC Congress 2013 contact the ESC Press Office.