A missed milestone cost Neurex Corp. investors Thursday after thecompany pushed back the timeline for completing a study of SNX-111, a drug for chronic pain.

The Menlo Park, Calif., company said it will not complete a PhaseII/III study of the neuron-specific calcium channel blocker by the endof the year as previously estimated. But Neurex said it intends to beready for filing a new drug application (NDA) for SNX-111 in amalignant pain indication and also for non-malignant pain, a newindication for which pivotal trials already are under way.

Neurex Chairman and CEO Paul Goddard said the company neverspecified when it would file the NDA but had disclosed theexpectation that enrollment in the 200-patient study would becompleted this year. Analysts following Neurex expected the NDAfiling to come in the second half of 1997, he said.

Neurex's stock (NASDAQ:NXCO) lost 14 percent, or $2.75,Thursday to close at $17.25.

Scott Sacane, an analyst at Montgomery Securities in San Francisco,said Thursday's news essentially pushed back the malignant painfiling by six months in his model and accelerated the non-malignantstudy about six months.

Sacane said Neurex stock had gained momentum in anticipation of anumber of events expected in the fourth quarter. "Some of the fastmoney blew out," he said of the Thursday decline. But he said themomentum is expected to return as other milestones are met. Thestock had gained $1.75 on Wednesday, Sacane noted.

SNX-111 is a chemically synthesized peptide based on calciumchannel blockers found in the venom of cone snails. The drug isbeing developed for pain indications in collaboration with MedtronicInc., of Minneapolis, and uses Medtronic's implantable pump todeliver drug to the spine. The goal is to stop pain sensations fromreaching the brain.

Patients, already on medication to control their pain, also take SNX-111 or placebo. If they don't respond in a given period they crossover to the other regimen. Patient assessment is used to evaluateresults.

Goddard attributed the enrollment delay of the SNX-111 trial incancer and AIDS patients mostly to difficulty in patient recruitment.Many oncologists were reluctant to refer patients from the cancercenters to pain-management centers, he said. Patients in theneuropathic, or non-malignant, study, on the other hand, are morereadily identifiable, he said.

Neurex also is beginning two additional, smaller studies formalignant and non-malignant pain, Goddard said, adding that theywill involve simpler protocols resulting in easier enrollment.

Separately Neurex is developing SNX-111 in collaboration withWarner-Lambert Co., of Morris Plains, N.J., to prevent brain damagefollowing head trauma or coronary artery bypass graft surgery. PhaseIII trials in the head trauma indication are expected to begin earlynext year.

Neurex in June filed a new drug application for another product,Corlopam, a dopamine receptor antagonist. The NDA was for controlof blood pressure during and after surgery, as well as hypertensivepatients for whom oral medication is not feasible or desirable.

Sacane said additional near-term events at Neurex include anannouncement of a European marketing partner for Corlopam, theinitiation of Phase II studies with Corlopam in kidney patients, and anew trial of SNX-111 for management of post-operative pain. n

-- Jim Shrine

(c) 1997 American Health Consultants. All rights reserved.