A rare brain infection killed a Dutch psoriasis patient who was taking a high dose of a drug with ingredients similar to Biogen Inc.’s Tecfidera.
Tecfidera is used for multiple sclerosis, which the Dutch patient didn’t have, and the medicine was made in a compounding pharmacy and not by Biogen. Yet the case has raised concerns that the infection could emerge even in people who aren’t showing warning signs, said doctors who looked at the death.
The progressive multifocal leukoencephalopathy infection was detailed in the New England Journal of Medicine, accompanied by a separate report on a multiple sclerosis patient who died of PML while taking Biogen’s drug. The company disclosed the multiple sclerosis patient’s death in October. Tecfidera sold $2.91 billion last year and is Biogen’s top product.
While physicians can monitor patients for signs of PML, the 64-year-old psoriasis patient didn’t have seriously low levels of infection-fighting white blood cells, thought to be an indicator of risk for PML.
The multiple sclerosis patient was on a high dose of Tecfidera for 4.5 years and, unlike the Dutch patient, had prolonged, severely low white blood cell counts.
The Dutch case is the first found in a person on dimethyl fumarate, the active ingredient in Tecfidera, who didn’t have early warning signs. That’s “a situation previously thought to be unlikely,” wrote Dennis Nieuwkamp and other doctors from the University Medical Center Utrecht, in the Netherlands.
Since the number of people getting dimethyl fumarate is rapidly increasing because of Tecfidera, “our case raises important questions with respect to safety monitoring,” the Dutch doctors wrote.
The new report isn’t likely to change use of Tecfidera, said Karen Blitz, director of the North Shore-LIJ Multiple Sclerosis Center in East Meadow, New York. The drug helps patients remain functional and many are willing to take risks for that benefit, she said. The danger is exceptionally rare, she said.
“If there is another case in a patient taking the currently recommended dose of Tecfidera, that would be interesting,” said Blitz, who wasn’t involved in the reports and has served as a Biogen consultant. “Unless there is more data indicating a risk, I’m going to continue to use the drug and monitor white blood cell counts.”
It’s not appropriate to extrapolate the risks of a pharmacy-mixed drug to Tecfidera, said Catherine Falcetti, a Biogen spokeswoman. The pharmacy-made drug containing dimethyl fumarate, called Psorinovo, is an unregulated product and differs from Tecfidera based on the amount and nature of the active substances, as well as the specific formulation and doses, she said.
There has been only one case of PML in a Tecfidera patient, out of more than 135,000 who have received it. Doctors are told to monitor patients’ blood to detect low white cell counts, a known risk for PML, Falcetti said.