Shares in InterMune will soar today after advisors to the US Food and Drug Administration voted in favour of recommending Esbriet for approval as a treatment for lung scarring.

The FDA’s Pulmonary-Allergy Drugs Advisory Committee has voted 9-3 to recommend approval of Esbriet (pirfenidone) for the treatment of patients with idiopathic pulmonary fibrosis to reduce decline in lung function in terms of its safety. However the panelists only voted 7 to 5 that it provides a “clinically meaningful benefit” for IPF patients.

One panellist, Michael Foggs, chief of allergy, asthma and immunology at the Advocate Health Centers’ Department of Medicine in Chicago, was quoted by Bloomberg as saying that “it’s not a perfect therapy but it helps fill the void and stem the tide”. Karen Gottesman, the panel's patient representative, told the Associated Press that "IPF is a fatal disease and you have to offer your patients hope. If this drug can offer your patients even a smidgen of hope, it's worth approving”.

IPF is characterised by inflammation and scarring in the lungs and comes with a median survival time from diagnosis of two-five years. It affects 200,000 people in Europe and the USA and there are no medicines approved in those territories for the treatment of IPF although Shionogi already sells pirfenidone in Japan as Pirespa.

InterMune, which filed Esbriet in Europe at the beginning of this month, said the FDA is expected to make its final decision by May 4. Analysts believe that the drug could be a blockbuster.