- A patient who had been treated with Biogen Idec's newest oral multiple sclerosis (MS) treatment, Tecfidera (dimethyl fumarate), died from pneumonia related to progressive multifocal leukoencephalopathy (PML) after 4.5 years of Tecfidera treatment.
- Although Biogen's MS drugs performed well in the third quarter (Tecfidera sales were up nearly 250% to $787.1 million, compared with Q3 2013), Biogen's stock was down 7% on the news on Wednesday, although it creeped up slightly on Thursday morning.
- According to Biogen Idec, the patient who died had been suffering from severe lymphopenia for more than three years.
Biogen's share price fell below $300 per share at one point on the news of a PML-related death in a Tecfidera patient. While there were no cases of PML in Tecfidera clinical trials, it is a potential side effect of oral MS medications.
In 2005, two patients treated with Tysrabi (natalizumab), another oral MS drug from Biogen, died from PML-related causes, causing the drug being withdrawn from the market. However, after patients advocated for access to the drug in 2006, the FDA allowed Tysrabi to re-enter the market with some restrictions.
Tecfidera is hailed as a breakthrough treatment for MS and has been targeted by Wall Street as a blockbuster drug with tremendous upside sales potential. Patients seem to like it, too. In the final analysis, it all comes down to risks versus benefits, and many patients are willing to take the risk associated with Tecfidera treatment.