After its experimental drug for lupus cleared a pivotal hurdle to authorization, shares in GlaxoSmithKline rose on Wednesday.

There were restrictions recommended and post-launch there were tough scrutiny by an expert advisory committee of the Food and Drug Administration that voted by 13 to 2 in favor of approving Benlysta for use in the US.

The recommendation of its arthritis advisory committee is not required to be followed by the US regulator but generating annual sales for GSK estimated potentially to reach £1bn ($1.6bn) by 2015, assessments were raised by analysts that it would make it to market.

As it attempts to find new drugs to replace existing high-margin treatments that are losing their patents, the move would mark a significant boost for the UK pharmaceutical company.

The US-based company that brokered an unusual deal with GSK to retain equal ownership, it is also an endorsement of Humane Genome Sciences.

The first new class of drug in 50 years to treat lupus, a chronic autoimmune disease that affects the skin Benlysta, will be a monoclonal antibody known generically as belimumab. It would also treat body organs causing pain, joints and inflammation and damage.