MS Drug Linked to Two Cases of PML
(HealthDay News) — An active ingredient in some psoriasis and multiple sclerosis medications, dimethyl fumarate, has been linked to two cases of progressive multifocal leukoencephalopathy (PML), according to two letters published in the April 9 issue of the New England Journal of Medicine.
One case involved a 54-year-old woman with multiple sclerosis. She died in October 2014 from complications related to PML and pneumonia, following 4.5 years of treatment with a time-delayed form of dimethyl fumarate carrying the brand name Tecfidera, researchers reported. The second case was a 64-year-old woman with psoriasis. She died in August 2014 from PML after being treated with a delayed-release dimethyl fumarate compound with the brand name Psorinovo for two years.
These cases follow reports linking other drugs containing dimethyl fumarate with PML, including Tysabri and Fumaderm, the researchers said. Based on these reported cases and other studies, doctors believe that dimethyl fumarate may affect a person's immune system if taken for an extended period, potentially opening the door to PML.
More than 135,000 MS patients in the United States have been treated with Tecfidera since its approval in March 2013, according to the second NEJM letter, which was coauthored by a doctor from the drug's maker, Biogen. "This is the single case of PML associated with Tecfidera," Biogen said in a written statement. "Based on experience in over 135,000 patients with MS treated with Tecfidera, there is no overall increased risk for serious infections, including opportunistic infections, for Tecfidera."