Regulators in the USA have completed their review of Novartis' multiple sclerosis pill Gilenya and concluded there is no clear evidence it played a role in the deaths of people who took the drug.

The US Food and Drug Administration began its investigation at the beginning of the year following a report of a patient who died after the first dose of Gilenya (fingolimod). The agency also evaluated reports of patients who died of cardiovascular events or unknown causes, thought to involve about 15 other people.

The FDA now says it "could not definitively conclude that Gilenya was related to any of the deaths" but based on its reevaluation of the data, it "remains concerned about the cardiovascular effects of Gilenya after the first dose". Therefore, the FDA has advised against its use in patients with certain pre-existing or recent (within the last six months) heart conditions or stroke, or who are taking certain antiarrhythmics.

Among a series of comments, the FDA said it continues to recommend that all patients starting Gilenya be monitored for signs of a slow heart rate for at least six hours after the first dose. Also, it is now recommending hourly pulse and blood pressure measurement for all patients starting on the drug.

The review comes a month after European regulators came to a similar conclusion and also updated the label to include more information on  cardiovascular risk. Novartis remains confident in the benefit-risk profile of the drug and believes Gilenya will still be a blockbuster.