By Debbie Strickland

Though Cambridge NeuroScience Inc. is not yet closing the door entirely, prospects for its lead product, the ion-channel blocker Cerestat, are looking gloomy.

A Phase III stroke trial in which enrollment was temporarily halted at 628 patients six months ago will not resume, though the Cambridge, Mass., company and partner Boehringer Ingelheim GmbH said they will continue to analyze data from the trial, along with findings from an abandoned Phase III brain injury trial, to decide whether continued development is justified, and, if so, just who the best patients are likely to be.

"I do expect we will find some positives in the data," said Elkan Gamzu, president and CEO. Final data analysis is expected around February.

Cerestat, a small molecule, is an N-methyl D-aspartate (NMDA) ion-channel blocker that prevents nerve cell death and brain damage following head injury or stroke by preventing excessive entry of calcium into those cells. In animal models, the drug saved up to 80 percent of tissue that would otherwise die.

The stroke trial first hit the skids when a June interim analysis raised safety questions that remain undisclosed. A few months later, an interim analysis of data from a Phase III brain injury trial failed to demonstrate efficacy.

As for the relationship with Boehringer Ingelheim, "it's the same as it was before," said Gamzu. "They, like we, want to see the data."

Their collaboration is a one-product agreement, with the Ingelheim, Germany-based big pharma company providing up-front fees and milestones of up to $43 million in exchange for widespread marketing rights to Cerestat. As of the end of 1996, the biotech firm had received $25 million of the payments. Boehringer Ingelheim also is paying 75 percent of development expenses.

The latest bad news about Cerestat barely nudged Cambridge NeuroScience's stock (NASDAQ:CNSI), which closed Tuesday at $1.719, down $0.063.

The bulk of the share shock — a loss in value of some 80 percent — hit earlier this year, following the June decision to pause the stroke trial and the September abandonment of the brain injury trial. (See BioWorld Today, June 25, 1997, p. 1; and Sept. 17, 1997, p. 1.)

The shares traded as high as $14 in February, the same month Cambridge NeuroScience closed a public offering of 2.4 million shares at $11 per share.

Firm's Cash Position Strong

The company is not planning to downsize, although some clinical group employees who prefer to work on advanced-stage projects resigned voluntarily in the wake of the Cerestat setbacks, Gamzu said.

Cambridge NeuroScience has enough cash — $41.8 million as of Sept. 30 — to last more than three years and possibly as long as five, said Gamzu.

Up next in Cambridge NeuroScience's pipeline is a molecule that also came out of the NMDA ion-channel-blocker program — CNS 5161, targeted at neuropathic pain and now wrapping up Phase I trials.

"We're finishing a concept study in volunteers, with the last dosing being done this week or next week," said Gamzu. "We hope to have data available toward the end of the year."

The next study of CNS 5161 will be a Phase II trial, said Gamzu.

The company will seek a partner over the next six months for its most advanced growth factor product candidate, recombinant human glial growth factor 2 (rhGGF2), a potential treatment for degenerative diseases of the nervous system, including multiple sclerosis and peripheral neuropathies. That product is slated to enter the clinic in early 1999. *