Human Genome Sciences will soar later today following the news that a US regulatory advisory panel has given the thumbs-up to Benlysta, partnered with GlaxoSmithKline, for lupus.

The Arthritis Advisory Committee of the US Food and Drug Administration has voted 13 to 2 to recommend approval for Benlysta (belimumab) for the treatment of autoantibody-positive patients with active systemic lupus erythematosus. The agency is scheduled to make a final decision by December 9, possibly making it the first new drug to be approved for lupus in more than half a century.

The panel voted 10-5 that there was substantial evidence Benlysta was effective in relieving pain and flares-up caused by lupus and 14 to 1 that it was safe, despite a slight rise in deaths and suicides among those on the drug compared to placebo. The near-unanimous vote was somewhat surprising given that before the meeting, FDA staffers had said that "various analyses of the data raise questions about the robustness of the efficacy findings".

The staffers also noted that the drug may not be effective in patients of African-American or African heritage, who "are known to have more aggressive SLE", and they added that the data demonstrated less effectiveness in the USA and Canada, compared with other regions. Indeed, one panel member David Blumenthal, a rheumatologist at Case Western Reserve University who voted against Benlysta, was quoted in the New York Times as saying "it’s unsettling to me to contemplate approval of a drug for patients in the USA, for practitioners in the USA, that does not seem to work for patients in the USA".  

His views were not shared by the majority of panellists nor by patients. Sandra Raymond, chief executive of the Lupus Foundation of America said the "historic vote" is "not only a victory for developers HGS and GSK, but also for the entire lupus research community and industry". The vote represents "a beacon of hope that new and improved treatments can be specifically developed for lupus", she added.

Under the terms of their agreement signed in 2006, the companies said they would share equally in Phase III/Vdevelopment costs, sales and marketing expenses, and profits. The latter are expected to be considerable and analysts believe Benlysta could be a $5 billion a year drug, in terms of peak sales.

In a research note on the UK major this morning, analysts at Collins Stewart said that "an almost unanimous recommendation for GSK’s first bona fide NME blockbuster prospect in living memory should herald the start of a new phase for the company".