European regulators have revealed that Sanofi-Aventis and Bristol-Myers Squibb have withdrawn a marketing authorisation application for a drug which combines the blockbuster Plavix with aspirin.

The European Medicines Agency said it had been formally notified by the firms’ decision to withdraw its application for DuoPlavin (clopidogrel/acetylsalicylic acid), which was expected to be used by patients already taking clopidogrel (Plavix) and acetylsalicylic acid (aspirin) for the prevention of atherothrombotic events in acute coronary syndrome. The application was submitted to the EMEA on May 30 and was under review by the agency's Committee for Medicinal Products for Human Use (CHMP).

Sanofi and B-MS say that the withdrawal of DuoPlavin was based on the request of the CHMP regarding “the need to document bioequivalence based on the current guideline on bioavailability and bioequivalence”. The companies noted that they intend to perform a new bioequivalence study “measuring plasma levels of clopidogrel parent compound to address the CHMP's request” but the results of that study “will not be available in the timelines defined by the centralised procedure”.

The EMEA said that more information about DuoPlavin and the state of the scientific assessment at the time of withdrawal will be made available in a question-and-answer document to be published on the agency’s website shortly.