Pozen’s proposed drug to treat migraine headaches demonstrated “superior headache relief” in two clinical trials, the drug development company said Tuesday after the markets closed.

The results were published in the Journal of the American Medical Association.

Wall Street reacted favorably, with Pozen (NASDAQ: POZN) shares trading up more than $1, or 8 percent, at $15.30 in after-hours trading.

The two studies involved more than 2,900 migraine sufferers.

Pozen is developing the drug, called Trexima, in partnership with GlaxoSmithKline. The test results were included in data presented by Pozen to the U.S. Food and Drug Administration, which has yet to grant approval for Trexima. Pozen resubmitted information to the FDA last month in another bid to gain approval.

GSK has paid Pozen more than $35 million thus far to develop the drug.

Pozen used its proprietary technology to combine an existing GSK migraine drug Imitrex with naproxen, a non-sterodial anti-inflammatory drug.

In the trials, Trexima proved more effective in providing relief at two hours and four hours when compared to a placebo and two through 24-hour sustained pain-free results when compared to solitary drug treatment from traditional triptan-based migraine drugs and naproxen.

"Recent research suggests that migraine is more complex than previously believed, consisting of multiple mechanisms that each contribute to migraine pain in different ways," said the lead author, Jan Lewis Brandes, M.D., in the JAMA article. He is an assistant clinical professor at Vanderbilt University School of Medicine and director of the Nashville Neuroscience Group.

"These studies found that Trexima, which is the first migraine-specific product designed to treat both inflammation and vasodilation [widening of the blood vessels] in a single tablet, provided superior efficacy compared to placebo and its individual components,” Brandes said in a statement released by Pozen.

Trexima combines 85 milligrams of sumatriptan and 500 mg of naproxen.

“Trexima was generally well-tolerated in these studies,” Pozen added. “No serious adverse events (defined as resulting in hospitalization or death) were reported in either study for patients taking Trexima.”

Last June FDA sent Pozen a so-called approvable letter in June that raised concerns about the safety of Trexima. Pozen and GSK teamed up to provide additional information in November.

Pozen received a $20 million milestone payment last fall from GSK following the submission of the new drug application for Trexima to the FDA.

GSK made as $15 million milestone payment to Pozen in May of 2004 based on reaching Phase III clinical trial milestones. At that time, the companies said they hoped to file the new drug application in the second half of 2005.

The FDA first asked for additional information from Pozen and GSK in June. The news sparked a sell-off in Pozen stock, dropping the price to $5.26 – a 52-week low – from $13.90 in one day. More than 25 million shares were traded.