There's been a second case of progressive multifocal leukoencephalopathy (PML) with dimethyl fumarate (Tecfidera) for multiple sclerosis, a Biogen spokesperson confirmed.
The company said it reported the case -- which wasn't fatal -- to regulators including the FDA but would not specify where the case occurred.
It occurred in a patient with primary progressive MS who had prolonged severe lymphopenia, which is on the drug's label as a risk factor for PML, according to Biogen spokesperson Catherine Falcetti.
"It's very similar to what we saw with the other case," Falcetti told 番茄社区. "It's within the risk profile, and the risk-benefit ratio remains favorable."
The other PML case with Tecfidera, reported in the New England Journal of Medicine earlier this year, occurred in a 54-year-old woman with MS, who had severe lymphopenia for 3.5 years.
Another case of PML was reported at that time, but it occurred in a patient who was taking a compounded formulation of dimethyl fumarate for psoriasis.
Biogen had also reported cases of PML with its branded oral dimethyl fumarate product Fumaderm, which is available on the European market as a treatment for psoriasis.
Tecfidera has been available on the U.S. market as a treatment for MS since 2013. Falcetti said the company does not anticipate any changes to the drug's label at this time, and she urged physicians not to change their practice with the drug but to be vigilant about prolonged severe lymphopenia as the label indicates.
Biogen is very experienced with PML -- it's the firm that introduced natalizumab (Tysabri) in 2004, only to discover a few months later that the drug raised the risk of PML in patients with latent JC virus infection.