InterMune will focus on developing pirfenidone, its second Phase III candidate for idiopathic pulmonary fibrosis, after halting development of Actimmune (interferon gamma-1b) for the lung disease when a Phase III trial failed to show a statistically significant benefit in mortality over placebo, the company announced March 5.

The Brisbane, Calif., company said it was discontinuing the Phase III trial, INSPIRE, based on the recommendation of the study's independent data monitoring board following a planned interim analysis. The analysis included 115 deaths in the 826-patient trial, with mortality among the Actimmune treatment arm (14.5 percent) similar to that of patients treated with placebo (12.7 percent).

Last April, InterMune announced that it had begun enrolling patients in CAPACITY, the company's program to evaluate pirfenidone, a small molecule p38-gamma inhibitor, for the treatment of IPF. The program, which will enroll 580 patients, includes two Phase III trials in patients with mild to moderate lung impairment, both with lung function as the primary endpoint.

Japanese drug maker Shionogi & Company, which holds the rights to pirfenidone in Japan, terminated a Phase II study of the drug in IPF early after a positive treatment effect was reported, according to InterMune.

"The Shionogi study authors reported that pirfenidone significantly reduced the rate of decline in lung capacity and decreased the frequency of acute exacerbations in patients with IPF," the firm reported.

Although InterMune no longer plans to study Actimmune for the treatment of IPF, the company said it has not determined whether it will halt interferon gamma-1b research altogether. It has explored using the therapy against ovarian cancer and liver disease.

Actimmune is already approved for severe, malignant osteopetrosis and chronic granulomatous disease, both of which primarily affect children. InterMune's Actimmune patent protection extends out to 2022, with one earlier composition of matter patent expiring in 2014.

The company has faced criticism for its marketing practices for Actimmune related to IPF. The company settled charges with the Department of Justice in October, agreeing to pay $36.9 million related to alleged off-label promotions for IPF patients despite the fact it wasn't approved for the indication (¹ Also see "InterMune Settles Medicaid/Medicare Fraud Charges For $36.9 Mil." - Pink Sheet, 27 October, 2006.).

Those promotions came in spite of the fact that an earlier Phase III study of Actimmune also failed to meet its endpoints.

In November, InterMune announced an exclusive licensing agreement with Roche for worldwide development and commercialization of its hepatitis C virus protease inhibitor program.

The company received an upfront payment of $60 million from Roche, which also is now funding 67 percent of the global development costs of the company's lead HCV candidate ITMN-191. InterMune could eventually earn $470 million in milestones from the deal, including a potential $35 million in 2007, the company said.

-Shirley Haley (s.haley@elsevier.com)

InterMune Halts Phase III Actimmune Lung Disease Trial

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