The asthma drug Zyflo fails to help patients with severe acne, according to a mid-stage trial carried out by the company Critical Therapeutics Inc. The drug, also known as zileuton, was neither better at controlling the number of inflammatory lesions than placebos under the company statistics.

Over the 12-week trial, patients treated with Zyflo had an average reduction of 11.5 inflammatory lesions. That compared with a reduction of 9.1 lesions in a group of other patients taking placebos far short of achieving statistical significance.

Patients treated with placebo showed a reduction of 16.4 lesions in the placebo group, but patients treated with Zyflo showed a mean reduction in the total number of lesions of 25.3.

The company stated the medicine showed a trend of potential benefit to some patients although the drug failed the primary goal of the trial.

Linda Lennox, the company spokeswoman, told the company will probably conduct a larger trial testing the medicine as an acne treatment, using information gleaned from the small recent "proof of concept" trial.

The company based in Lexington, Massachusetts, said that it is continuing to analyze the data and is working with the investigators to further interpret the results.

Zyflo blocks an inflammation-causing enzyme called 5 lipoxygenase (5-LO). It was approved by U.S. regulators in 1996 for treating asthma patients 12 years of age and older. At the time, the drug was owned by Abbott Laboratories Inc., which sold it for a number of years before licensing it to Critical Therapeutics in late 2003.