"We're very encouraged by our U.S. experience," Kingsley said. The approval was widely expected after the European Medicines Agency endorsed the drug in November. European health regulators typically follow EMA recommendations within a couple of months. Tecfidera will be the third oral multiple scelrosis drug available in Europe. However, if its impressive early performance in the United States is any indication, the Biogen drug is likely to surpass sales of Novartis' Gilenya and Aubagio from Sanofi. Tecfidera has consistently shattered Wall Street sales forecasts and is well on the way to racking up more than $1 billion in sales in its first year on the market. Biogen reported Tecfidera sales of $398 million for the fourth quarter of 2013, only the medicine's third full quarter since winning U.S. approval. It is also approved for sale in Canada and Australia. The introduction in Europe will start in the coming weeks, although its full roll-out will take place over the course of this year and next as Biogen must negotiate reimbursement for the treatment on a country by country basis. First up will be Germany, "where you can get pricing reimbursement rather quickly," Tony Kingsley, Biogen's head of global commercial operations, said in a telephone interview. "We're ready to go," said Kingsley, adding that Biogen's Germany sales force for the new drug has been in place for months. Tecfidera's prospects in Europe had been in doubt at one stage because of uncertainty about protection against generic copies. This issue was resolved in November when Biogen won 10 years of regulatory exclusivity. There are an estimated 400,000 people in Europe with multiple sclerosis. Biogen declined to comment on what type of market share Tecfidera was likely to seize in Europe.