By Charles Craig

SAN FRANCISCO — While most migraine drugs treat the blood vessel dilation thought to cause the severe headache pain, CoCensys Inc. is taking a different approach based on recent research showing inflammation also may play a role in the disabling order.

David Lee, CoCensys’ vice president of research and development, said the Irvine, Calif., company expects to begin in March 1997 a Phase II trial of its synthetic epalon, ganaxolone (CCD 1042), for treatment of migraines.

Results of the 250-patient study are expected in late 1997 or early 1998. Lee said if the data are positive, CoCensys would move immediately into a Phase III trial.

CoCensys’ fast-track development line for ganaxolone is made possible by demonstration of the drug’s safety in Phase I trials for epilepsy.

The company has two Phase II studies under way in childhood and adult epilepsy. Data from the childhood trial is expected by mid-1997 and results from the adult trial are scheduled for release by the end of 1997.

Lee said Phase III studies of ganaxolone for epilepsy also would begin in early 1998 along with the trials for migraine headaches, which represent a much larger market for CoCensys.

Lee discussed the start of the company’s migraine program at the 15th Annual Hambrecht & Quist Healthcare Conference.

Lee said CoCensys is launching development of ganaxolone based on research at Massachusetts General Hospital in Boston showing that the inflammation, which follows blood vessel dilation in the brain, plays a role in migraine and that ganaxolone suppresses the inflammation.

Ganaxolone is a synthetic epalon, which is a naturally occurring molecule in the brain. Epalons modulate gamma-amino butyric acid (GABA) receptors, activating release of GABA neurotransmitters, which calm excited brain cells.

Low levels of GABA in the brain are associated with anxiety and convulsions, while high levels of the neurotransmitter can result in sedation and sleep.

Migraines, which affect 10 million people in the U.S., are believed to be caused by dilated blood vessels in the brain. Current treatments, such as Imitrex sold by London-based Glaxo Wellcome plc, are serotonin receptor agonists that constrict blood vessels to relieve the pain.

However, serotonin receptors also are present in heart blood vessels and the drugs cannot be used by people with heart disease. In addition, they also don’t affect inflammation, which is a source of pain. Ganaxolone would not have the side effects associated with Imitrex and would treat the inflammation.

ConCensys stock (NASDAQ:COCN) closed up $0.625 to $7.75 on Tuesday.