It's not shaping up to be a great week for Sanofi ($SNY). Yesterday, the company announced that its multiple sclerosis drug candidate Lemtrada didn't meet its secondary endpoint in a clinical trial, sending shares reeling. Now, European regulators say they're broadening their review of Multaq, the atrial fibrillation treatment, after a study flagged potential cardiovascular risks in some patients.
The European Medicines Agency said it will be sifting the data from that study of Multaq in patients with permanent atrial fibrillation, which Sanofi halted last week on the recommendation of its safety board. Patients using Multaq saw a higher rate of adverse CV events and of hospitalizations than placebo patients did. Currently, Multaq is approved for patients with a temporary form of AF, and the company had been looking to broaden its use to patients with long-term AF.
It's high stakes for the French drugmaker. Multaq is one of the drugs it's been counting on to help fill sales gaps as it loses patent protection on some of its biggest products. Analysts have pegged the drug as a blockbuster, but that all depends on how the risk-benefit analysis shakes out. The U.K. cost-effectiveness watchdog gave Multaq a thumbs up, but only as a second-line treatment, and French authorities recently pulled back on an earlier reimbursement recommendation.
The EMA was already taking a close look at Multaq, with a safety review prompted by two cases of liver failure in patients using the drug. The agency says that its experts will assess the new study and consider at their next meeting whether further action is necessary. That meeting begins July 18. Meanwhile, French officials warned doctors to be vigilant about prescribing the drug. "Pending further information, [we recommend] doctors consider cardiovascular as well as liver risks before prescribine dronedarone," the French health agency said (as quoted by Dow Jones).
For its part, Sanofi says it has shared the new trial data with health regulators around the world and is undertaking its own analysis as well. "Sanofi is cooperating fully with the European Medicines Agency on the review of Multaq," the company said in a statement.