Gilenya Safety Concerns Rise as Market Share Drops

Fewer and fewer doctors are prescribing the multiple sclerosis drug Gilenya in the wake of nearly a dozen deaths and safety investigations in the United States, Europe and Canada. 

Novartis logged a small drop in market share in January, as news of Gilenya safety concerns began to spread, amid reports that some patients died soon after starting on the drug, with at least one death occurring after the first dose.

The drop, although small, came on the heels of more than a year of growth at about 15% per month. Although Novartis maintains that the drug still has a lot of potential, many doctors are backing away from the drug and looking at alternatives.

Gilenya (fingolimod) was approved in 2010 as an oral treatment for relapsing forms of MS in adults. It is used to reduce how often flare-ups occur and to delay the onset of physical disability caused by MS.

The risk of some heart irregularities after the first dose were a concern before the drug was approved. Known side effects of Gilenya include a decrease in heart rate and/or atrioventricular conduction after the first dose. It is also known to increase the risks of developing heart blocks or bradycardia when taken with some other drugs, including beta blockers and calcium channel blockers.

The FDA has indicated that doctors should inform patients that Gilenya may cause serious side effects, such as a low heart rate, that can cause symptoms including dizziness, fatigue and palpitations after the first dose. The heart rate typically returns to normal within the first month of taking the drug. Patients using the medication have been urged to contact their health care provider if these symptoms occur.