Its shares have settled down since takeover rumours began earlier this week but InterMune is bracing itself for offers from suitors across the pharmaceutical industry.

A variety of unnamed sources have been reported as saying that InterMune is assessing its options and has hired Goldman Sachs and Centerview Partners to help. The biotech’s attraction is Esbriet (pirfenidone), which is already marketed in Europe and is expected to be approved soon in the USA for idiopathic pulmonary fibrosis.

The drug was rejected by the Food and Drug Administration in May 2010 but further promising data presented at the American Thoracic Society meeting in San Diego in May has formed the basis of a resubmission. Analysts believe approval will come soon, possibly around the same time as rival IPF product nintedanib from Boehringer Ingelheim.

Having an nearly-approved product in the USA in an area of unmet need makes InterMune extremely attractive and the rumour mill has thrown up a number of names, basically anyone in respiratory. These include Sanofi, AstraZeneca, GlaxoSmithKline, Actelion, Gilead Sciences, Merck & Co and Roche; InterMune's market capitalisation is in the region of $5 billion.