Sanofi-Aventis has been given a later-than-expected review date by regulators in the USA for its experimental heart drug and potential blockbuster Multaq.

The French drugmaker issued a short statement this morning that the US Food and Drug Administration intends to discuss the Multaq (dronedarone) application through its cardio-renal advisory committee on March 18. This has taken observers by surprise somewhat seeing as the FDA granted a priority review for the drug in July and these normally take six months, not nine.

The delay would once again appear to lie with the FDA and the staff shortages it is suffering from. There is no indication that there may be a problem with the data filed on Multaq a multi-channel blocker that has anti-adrenergic properties and has been developed to treat atrial fibrillation.

The Paris-headquartered company has presented a host of promising data on Multaq of late. The most recent was a new analysis of a previously reported study which showed that Multaq cut the total number of hospital days in patients with AF by 28% compared to placebo and cut total length of time spent in the hospital for heart-related reasons by 35%.

However the path to possible approval for Multaq has been a tricky one. In 2006, the FDA issued a ‘not-approvable’ letter for the drug, asking for more clinical evidence of the drug’s efficacy and safety.