By Mary Welch

CoCensys Inc.'s tablet formulation of ganaxolone failed in a Phase II trial to reduce migraine headache pain in a statistically significant way.

"It just didn't work," said F. Richard Nichol, president and CEO of the Irvine, Calif.-based company. "It's very disappointing, because it would have created a whole set of exciting opportunities. We had some success in the liquid formulation, but we thought we could improve on it — and make it more commercial — with the tablet formulation. We are dropping our work in ganaxolone for acute migraine, but will continue to go forward in other areas."

The double-blind, placebo-controlled study involved 325 patients at 19 sites throughout the country. Endpoints were pain relief at two and four hours after dosing. The only statistically relevant side effects were somnolence, dizziness and fatigue. Ganaxolone did achieve statistically significant results in pain relief at two hours in a subset of 45 women who were given ganaxolone or a placebo within five days following the state of menses.

"In that subgroup, ganaxolone achieved a 25 percent better result than the placebo," said Joann Data, executive vice president, product development and regulatory affairs. "A large percentage of migraine sufferers are women who experience the problem around their periods. But these results are just not enough to go forward on."

Ganaxolone is a synthetic version of naturally occurring neuroactive steroids known as epalons, which suppress inflammation in the lining of the brain.

CoCensys is seeking a partner to develop ganaxolone for epilepsy, for which the drug has shown promising results in previous clinical trials. In a Phase II trial, the company tested ganaxolone in 52 epilepsy patients who no longer responded to antiseizure medications and were suffering from such debilitating seizures they were scheduled for surgery to remove the portion of their brains that was instigating the seizures. Prior to surgery, patients were given either oral ganaxolone or a placebo. Patients receiving the placebo were twice as likely to suffer a seizure. (See BioWorld Today, Nov. 10, 1997. p. 1.)

Talks Under Way With Prospective Epilepsy Partners

"We had put ganaxolone for epilepsy on hold — even though we had received very positive results — because the market for acute migraine is so much larger. After these results, we're at Plan B, which is to go forward with epilepsy," said Data. "We had been in talks with potential partners and we are having talks with two fairly significant parties interested in it for epilepsy."

The company can quickly go into Phase III trials for the epilepsy indication, she said.

It is also looking at ganaxolone for migraine prophylaxis and seeking a partner for that program.

Another potential partnership project centers on the development of backup water-soluble compounds for acute migraine therapy.

Despite the setback, CoCensys has $15 million in cash, enough to keep the company going well into 1999.

CoCensys' stock (NASDAQ:COCN) closed Friday at $0.625, down $0.469. *