Data from clinical trials of Neurex Corp.'s SNX-111, a drug derivedfrom the venom of cone snails for treatment of severe pain, showedmore than 66 percent of patients participating in the Phase II studieswere able to reduce use of other medications by 50 percent or more.
For some patients, investigators said, SNX-111 was substitutedcompletely for morphine and other narcotics.
Paul Goddard, Neurex's chairman and CEO, said the Phase II dataalso revealed SNX-111 significantly reduced pain intensity.
The drug, a chemically synthesized peptide, blocks neuron-specificcalcium channels, preventing transmission of pain sensations to thebrain.
Neurex, in collaboration with Medtronic Inc., of Minneapolis, isevaluating SNX-111 in two Phase III trials for malignant and non-malignant pain. A feasibility study for treatment of post-surgical painalso is under way. And two other 100-patient trials are expected tobegin early in 1997.
Menlo Park, Calif.-based Neurex is using Medtronic's implantablepump to deliver the drug to the spine.
The Phase II SNX-111 studies, whose results were reported lastweekend at a meeting of the American Pain Society in Washington,evaluated 24 patients who failed to achieve relief with currentlyapproved pain treatments, including morphine.
"Basically these patients were at the end of the road in gettingsymptomatic relief for their pain," Goddard said.
When enrolled in the trials, the participants had received a broadrange of pain medications, including narcotics, anti-depressants, anti-convulsants and anesthetics.
Following administration of SNX-111, about 16 of the 24 patientsreduced reliance on other medications from 50 percent to 100percent.
Goddard said the Phase II data supported treatment protocolsestablished for the on-going Phase III studies. The company expectsto file a new drug application for SNX-111 by the end of 1997.
Among SNX-111's advantages is lack of adverse events associatedwith narcotics. In the Phase II trials, patients experienced a number ofside effects as they withdrew from standard therapies, such asmorphine, but investigators did not attribute the reactions to Neurex'sdrug.
Neurex also is evaluating SNX-111 as a treatment for preventingbrain damage caused by head trauma, heart bypass surgery and strokein a collaboration with Warner-Lambert Co., of Morris Plains, N.J.
Neurex's stock (NASDAQ:NXCO) closed Monday down $0.875 to$14.75. n
-- Charles Craig
(c) 1997 American Health Consultants. All rights reserved.