Biogen Idec jumps on Techfidera approval

Moody’s Investors Service also raised Biogen Idec’s ratings outlook to positive.Suzanne Kreiter/Globe Staff/File/Globe Staff

It was a good week for Biogen Idec Inc. shares after US regulators OK’d its first pill to treat multiple sclerosis, cementing the Weston company’s dominance in MS treatments. The FDA approved Tecfidera as a “first-line” treatment, meaning doctors can prescribe it for newly diagnosed patients and those already taking MS drugs. Analysts say Tecfidera potentially could become one of the top-selling prescription drugs of all time by the end of the decade.