Psychiatric Drug Mix disapproved for treatment of Migraine headaches

Pozen Inc. (POZN) on Tuesday said U.S. regulators rejected its experimental migraine drug because it was not more effective than an existing treatment, sending the company's stock down 40 percent. Pozen said the Food and Drug Administration issued a non-approval letter on its experimental drug MT100, a combination of naproxen and another treatment, because it did not prove substantially more effective than naproxen alone at sustaining pain relief.

The FDA was also concerned with the risk that patients could suffer from tardive dyskinesia, a neurological syndrome caused by the long-term use of certain medicines used for psychiatric disorders. The drug that Pozen combined with naproxen in MT100, called metoclopramide, has been associated with uncontrollable motions characteristic of tardive dyskinesia patients.

Tardive dyskinesia is characterized by repetitive, involuntary, purposeless movements, such as grimacing, tongue protrusion, lip smacking, puckering and pursing, rapid eye blinking and rapid movements of the arms, legs, and trunk. The FDA did not observe any raised risk of tardive dyskinesia in clinical trials of MT100, but was apparently still concerned by it.

``Given the number of patients exposed to MT 100 for at least one year in your database (about 300), the absence of any detected cases is consistent with a true rate of TD of about 1 percent, an unacceptably high risk in the absence of any demonstrated advantage of the product,'' the FDA said in its letter to the company.