Shares in Pozen (Nasdaq: POZN) surged Tuesday after the drug development firm said new test results addressed regulatory concerns about a migraine drug it is developing with Glaxo.

Pozen said the proposed migraine drug Treximet produced no genotoxic “aberrations” in human volunteers. The Food and Drug Administration rejected the drug last year, citing genotoxic impact on hamsters that had been used in tests. The drug had been called Trexima.

The FDA concurred with Pozen on the format for the new trial. Pozen has been trying to win approval for the drug since 2005.

GlaxoSmithKline (NYSE: GSK) is working with Pozen in development of Treximet.

Pozen shares traded up more than 6 percent to close at $12.85 Tuesday. In August, Pozen shares plunged 46 percent after the FDA declined to approve Trexima and asked for additional information.

The FDA expressed concerns about genotoxicity, or damage to DNA, that was “seen for the combination of naproxen sodium and sumatriptan,” Pozen said in a letter in August. Those are the ingredients Pozen has combined in one pill. The genotoxicity was observed in one of four studies, Pozen said.

In an earlier review of the drug, the FDA expressed concern about cardiovascular side effects.

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

According to the American Medical Association, migraines affect an estimated 28 million people.

GSK has paid Pozen more than $35 million to develop the compound.