Tecfidera is said to be the world’s top-selling drug treatment for multiple sclerosis, and sales account for a third of Biogen’s total revenue, around $1.03 billion in the third quarter.
According to several news outlets, including Reuters Health News, there have been “clinically significant cases” of liver injury reported in patients who were treated with the drug in the postmarketing setting.
It is still unclear whether this new development will adversely impact Biogen sales of its blockbuster medicine brand in 2017.
Current Rates of Liver Injury Associated with Tecfidera
According to a Biogen spokeswoman, so far there have been 14 cases of liver injury reported out of roughly 230,000 patients, and while most of these cases were resolved after the patients stopped taking the medicine, some did require hospital care.
None of the cases reported were serious enough to directly result in liver failure, liver transplant or death, although any of these three could come from a combination of factors such as “serum aminotransferase elevations” and “increased levels of bilirubin” relating to Tecfidera symptoms.
Signs of injury which have been observed include elevation of serum aminotransferases to more than five times the normal limit and elevation of total bilirubin more than two times the normal limit.