Shares of Pozen (Nasdaq: POZN) skyrocketed 25 percent after the company reported favorable results of a two-year rat carcinogenicity study for its oral migraine drug MT 100.

In late morning trading, POZN stock was priced at $14.36, an increase of $2.86 over Tuesday’s close of $11.50. It approached the $15 mark earlier on, but is still short of a 52-week high of $19.40 achieved in September. POZN has climbed back from a low of $2.25 it hit in March 2003.

Pozen closed the day at $14.54, a gain of $3.04, or 26 percent.

Pozen says results from the carcinogenicity study show no evidence that the administration of the maximum tolerated doses of metoclopramide and naproxen, the two active components in MT 100, produced any “statistically significant” differences in findings from those seen with metoclopramide alone.

None of the tumors observed in the study were considered to be directly related to the administration of metoclopramide or naproxen, according to the Chapel Hill-based company, and all were considered to be secondary to metoclopramide-induced increases in the levels of the growth hormone prolactin in the affected rats.

Pozen submitted the study report Tuesday to the FDA, thus completing the MT 100 New Drug Application (NDA) submission initially made in last July. The FDA accepted the NDA for filing in October and is expected to complete its review by May 31.

“We are very pleased with the outcome of the study, and we are grateful to the FDA for allowing us to submit these data during the NDA review process without affecting the date by which the FDA should complete its review of the NDA–,” said John Plachetka, chairman, president and chief executive officer of Pozen.

One of the company’s other migraine treatments, MT 300, initially received a “not approvable” letter from the FDA last October. Pozen continues to work with the agency on further review of the drug.