The news that the USA’s InterMune is to halt development of Actimmune in patients with idiopathic pulmonary fibrosis has done major damage to the company’s share price.

A Phase III clinical trial, called Inspire, which was evaluating Actimmune (interferon gamma-1b) in patients with IPF, a disease of inflammation that results in scarring or fibrosis of the lungs, halted upon the recommendation of the study's independent data monitoring committee. In an interim analysis that included a total of 115 deaths, the committee found the overall survival result crossed a predefined stopping boundary for lack of benefit of Actimmune relative to placebo and among the 826 randomised patients, there was not a statistically significant difference between treatment groups in overall mortality (14.5% in the Actimmune group as compared to 12.7% in the placebo group).

Dan Welch, Intermune’s chief executive, said that although the firm was disappointed by this result with Actimmune, which is approved for chronic granulomatous disease and severe, malignant osteopetrosis, “we remain committed to addressing the significant unmet medical need in IPF with pirfenidone,” which is has generated impressive data in several Phase II studies and in a Phase III trial run by partner Shionogi.

Since the halting of the Actimmune IPF trial, Intermune stock has slumped and finished down 22% to $22.15 at the close of trading on Tuesday. Nevertheless, some analysts argue that all is not doom and gloom at the firm.

Brian Abrahams, an analyst at CIBC World Markets, lowered his price target for InterMune to $31 from $46, and he now expects the company to rake in $40 million in Actimmune sales in 2011, down from $615 million. However, he believes the stock is still a good buy due to the potential of ITMN-191 for hepatitis C which is in Phase I and is being developing with Roche.