Gilead Ends Trial of Novel Drug for Rare Lung Disease on Lack of Efficacy

Gilead Sciences Inc., the world’s biggest maker of AIDS drugs, said it is stopping a late-stage study of an experimental lung-disease therapy because it didn’t help patients with the condition, idiopathic pulmonary fibrosis.

The drug, ambrisentan, was in the final stage of testing usually required for U.S. approval, the Foster City, California- based company said in a statement today. The decision to halt the study followed an interim analysis of data by a monitoring committee and the company’s review, according to the statement.

Gilead said on Dec. 20 that it had agreed to acquire Arresto Biosciences Inc., of Palo Alto, California, for $225 million. Arresto’s lead experimental drug is a monoclonal antibody being tested for cancer and idiopathic pulmonary fibrosis, the same fatal lung disease that Gilead’s now-canceled study for ambrisentan was targeting.

“Gilead is conducting a thorough review of the data and will communicate the full results of this analysis to the medical community when they are available,” Gilead said in the statement.

Nathan Kaiser, a Gilead spokesman, said there is no connection between the decision to stop the ambrisentan study and the company’s deal with Arresto.

“Gilead was just informed of the results of the data monitoring committee this week,” Kaiser said in a telephone interview today.

Ambrisentan received U.S. approval in 2007 as a treatment for pulmonary arterial hypertension, a narrowing of the arteries that causes shortness of breath and heart failure. It is marketed under the brand name Letairis.

Gilead shares fell 2 percent to $35.60 at 6:07 p.m. New York time in extended trading on the Nasdaq Stock Market after closing down 22 cents to $36.34.

To contact the reporter on this story: David Olmos in San Francisco at

To contact the editor responsible for this story: Reg Gale at

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