Biogen Idec has posted second-quarter results which show that sales of its oral multiple sclerosis drug Tecfidera have comfortably passed analyst forecasts, pushing net profits up 46%.

Earnings came in at $714.5 million, while revenues increased 40% to $2.06 billion. The biggest earners were the MS drugs Avonex (interferon beta-1a), which were pretty flat at  $773.7 million and Tysabri (natalizumab), which contributed $533.4 million, up 38%.

However, the performance of Tecfidera (dimethyl fumarate), caught the eye again, bringing in $700.4 million, up from around $192 million a year earlier, and $585 million of that came from the USA.

As for Biogen's other products, rheumatoid arthritis and cancer drug Rituxan (rituximab) and the recently-approved chronic lymphocytic leukaemia treatment Gazyva (obinutuzumab) partnered with Roche brought in $303 million, up 5%. Fampyra, a prolonged-release formulation of fampridine to improve walking in adults with MS, climbed 33% to $22.3 million, while the psoriasis treatment Fumaderm (fumaric acid) inched up 1% to just under $16 million.

The strong performance of Tecfidera means that for the full year, Biofen’s revenues are now expected to grow 38%-41%, up from previous guidance of 26%-28%.