European regulators have recommended approval of two new multiple sclerosis pills from Biogen and Sanofi, both of which are expected to become major sellers.

Friday's decision by the European Medicines Agency (EMA) was particularly significant for Biogen, since the U.S. biotech company is still awaiting a verdict on Tecfidera, or BG-12, in the United States.

Biogen's Tecfidera is one of the most highly anticipated new drug approvals for the pharmaceuticals industry in 2013, with analysts predicting billions of dollars a year in sales.

It will compete in the oral MS drug market against Novartis's existing Gilenya and Aubagio, but many investors already see it as best in class.

"We believe Tecfidera will raise expectations for what people living with MS can achieve with their therapy," Biogen CEO George Scangos said in a statement welcoming the news.

Oral drugs are changing the MS market dramatically, by offering patients a highly effective alternative to traditional injections, which can be painful and may cause flu-like symptoms.

Tecfidera and Sanofi's Aubagio were both endorsed for treating relapsing remitting multiple sclerosis (MS), though the EMA decision still needs to be finalised before the drugs can be launched.

Aubagio was approved by the U.S. Food and Drug Administration (FDA) for the same use in September, while an FDA decision on the Biogen product is due by March 28.

Mark Schoenebaum, an analyst with ISI Group, said the European decision on Tecfidera was reassuring since the EMA only flagged up two safety issues.

The agency's press release merely highlighted as side effects flushing, or redness of the skin, and gastrointestinal events, such as diarrhoea and nausea.

Four-in-one HIV tablet

The London-based agency also gave a green light to Gilead Sciences's four-drug combination pill to treat HIV/AIDS, called Stribild, and recommended wider use of Bayer and Johnson & Johnson's anti-clotting drug Xarelto for treating acute coronary syndromes.

The flurry of positive recommendations for new medicines, each of which analysts believe will become multibillion-dollar-a-year sellers, underscores a recent pick-up in research productivity by the pharmaceutical industry.

Sales of the Biogen MS drug are expected to reach $3.0 billion a year by 2017, outstripping revenues by the same time of $2.5 billion for Gilenya and $1.1 billion for Aubagio, according to consensus forecasts compiled by Thomson Reuters Pharma.

Tecfidera will add an important new leg to Biogen's multiple scelorisis business, which already includes the injectable drugs Avonex and Tysabri.

Ariad Pharmaceuticals also won a recommendation for its drug Iclusig for chronic myeloid leukaemia, while Baxter International and Halozyme Therapeutics secured EMA backing for HyQvia as a treatment for immunodeficiencies.

Recommendations for marketing approval by the European Medicines Agency's Committee for Medicinal Products for Human Use, or CHMP, are normally endorsed by the European Commission within a couple of months.