Serious safety concerns over a popular oral medication used to treat multiple sclerosis have prompted Health Canada to launch a full investigation.
The department made the announcement on Monday after reports of 11 deaths worldwide that have been linked to the drug fingolimod.
When fingolimod, sold under the brand name Gilenya, was approved in Canada last March, it was known the drug could increase the risk of heart problems, such as a decreased or abnormal heart rate, after the first dose. But Health Canada and many other regulators around the world ruled that the benefits of the drug outweighed the risks.
None of the deaths linked to Gilenya occurred in Canada. But Health Canada has received 52 reports of adverse events linked to fingolimod since last April. At least 14 reports came from patients who experienced a decreased heart rate after taking the drug. Other reported problems include blood pressure fluctuation, fatigue and dizziness.
Gilenya, marketed by Novartis, is the first oral medication approved for treatment of relapsing-remitting MS, the most common form of the disease. Relapsing-remitting MS is characterized by unpredictable flare-ups of new or worsening symptoms, followed by a period of partial or full recovery.
The disease attacks the myelin, a protective covering wrapped around the nerves of the central nervous system. It can cause fatigue, vision and balance problems, pain, depression, bladder dysfunction and disability
Many doctors and patients saw the introduction of Gilenya as a major step forward that could reduce or eliminate the need for frequent injections of medication, an unpleasant inconvenience that can negatively affect the quality of life and cause a lack of adherence to medication schedules.
Gilenya is considered a “second-line” medication, prescribed after other options have failed, and is designed to reduce attacks or flare-ups.
Other pharmaceuticalcompanies are racing to bring their oral MS therapies forward in the hope of tapping into a potentially huge market for the drugs.
But concerns over the safety of Gilenya are raising questions about whether oral MS medications have a real future.
Of the 11 reported deaths possibly linked to Gilenya, four involved serious heart-related events, while seven are unexplained. One of the unexplained deaths involved a patient in the U.S. who died within 24 hours of taking the first dose of Gilenya.
Amit Bar-Or, an associate professor at the Montreal Neurological Institute and McGill University, said it’s too early to say if Gilenya is unsafe and a balance probably can be found between the drug’s risks and benefits.
Dr. Bar-Or, who was also one of the investigators involved in clinical trials of Gilenya, noted that physicians are supposed to monitor patients for several hours after they receive their first dose in case of a decreased heart rate or any other problems.
One big question now facing regulators is whether requirements for patient monitoring are enough to make the drug safe in light of the reported side effects and deaths.