Biogen Idec (BIIB 0.87%) announced today that its drug Tecfidera has been approved for the treatment of patients with multiple sclerosis in European Union nations. It's been approved as a first-line oral treatment for people with relapsing-remitting multiple sclerosis (RRMS), the most common form of multiple sclerosis, according to the company.

"TECFIDERA exemplifies our commitment to deliver innovative therapies that help people living with serious diseases," Biogen Idec CEO George Scangos said in a press release.

Biogen Idec announced last March that Tecfidera had been approved as a first-line oral treatment of multiple sclerosis in the U.S. It is now the most prescribed treatment in the United States for forms of MS that involve relapsing after six months. The capsule was also approved in 2013 for use in both Canada and Australia.

Biogen Idec said today that the European Commission's approval was based on Tecfidera's clinically proven results, including one study in which patients have been tracked for six and a half years. It noted that the drug has been "shown to significantly reduce important measures of disease activity, including relapses and the development of brain lesions, as well as to slow disability progression, while demonstrating a favorable safety and tolerability profile."

When Biogen Idec reported third-quarter earnings in October 2013, it highlighted a 32% rise in revenue year over year to $1.8 billion. It attributed this gain largely to addition of Tecfidera to its portfolio of prescription drugs, as the MS drug had $286 million in revenue in the quarter.

When the earnings results were announced, Scangos said in a prepared statement that Tedfidera was valuable to patients and physicians and "we are pleased with how it has complemented our robust portfolio of MS therapies."

Scangos noted in today's announcement, "We already have seen TECFIDERA's significant impact on transforming the standard of care for MS where it is available and are excited to quickly bring its benefits to patients in the EU as well."