Alexza Pharmaceuticals Inc said preliminary results from a mid-stage trial of its migraine drug showed it did not meet the primary goal of headache pain-relief at two hours post-dose.

The drug, AZ-104, was numerically superior to dummy drug in pain relief at two hours post-dose, but these differences were not statistically significant, the company said.

The study was designed to evaluate the treatment of a single migraine attack of moderate-to-severe intensity in each of the 366 migraine patients, with or without aura.

Two doses of AZ-104, 1.25 mg and 2.5 mg, and placebo were evaluated in the trial. There were no serious adverse events, and AZ-104 was generally safe and well tolerated, the company added.

Shares of Alexza closed at $2.90 Friday on Nasdaq. They were trading in low volumes at $2.43 before the bell. (Reporting by Jennifer Robin Raj in Bangalore; Editing by Aradhana Aravindan)