Another blow to a promising new multiple sclerosis pill has been reported by several media outlets, as a patient taking Novartis’ Gilenya multiple sclerosis pill contracted a potentially deadly brain infection, adding to safety concerns about the Swiss drugmaker’s most promising potential blockbuster.
The patient used Tysabri, an injection from Biogen Idec Inc. and Elan Corp., before using Gilenya, Novartis said in an e-mailed statement today. Tysabri increases the risk of the viral infection, known as progressive multifocal leukoencephalopathy, that usually leads to death or severe disability, according to a warning the drug’s label has carried since 2006.
“The current assessment is that Tysabri is the drug most likely associated with this case of PML,” Novartis said in the statement. Because there is currently no confirmed case of PML reported to Novartis in a Gilenya (fingolimod) treated patient without previous Tysabri (natalizumab) treatment. “However, a contribution of Gilenya to the evolution of this case cannot be excluded.”
Regulators suspended Tysabri from the market in 2005 after some patients developed PML, then allowed its return in 2006 with a risk-management program for people who didn’t benefit from rival medicines. A revised Tysabri label now warns that patients who have antibodies against the so-called JC virus are more susceptible to developing PML. Biogen and Elan developed a test able to detect the antibodies in patients, which has eased safety concerns.
While the news might slow the uptake of Gilenya, it’s a positive development for Tysabri because doctors may hesitate to switch patients to Gilenya from Tysabri solely on safety concerns, Yee said.
“This case seems to suggest switching to Gilenya does not completely mitigate that risk,” he wrote.