New Drugs on Horizon for Prolonged Brain Damage
Pfeiffer, Naomi, Drug Topics
For the first time, there are drugs within sight to protect brain cells from the motor and cognitive damage that continues long after the impact of severe head injury, international trauma experts told a recent seminar for medical writers in New York City.
"With impressive research from laboratories now being made available to physicians, coupled with very innovative drug development by pharmaceutical companies, several substantial remedies should be ready in two to three years," said Lawrence H. Pitts, M.D., chief of neurosurgery, University of California in San Francisco.
The need is urgent, he and other speakers stressed. Some 75,000 Americans annually sustain disabling brain damage from car crashes, gunshot wounds, or falls. The cost: about $25 billion.
Two promising antioxidant drugs--designed to reduce the damage that spreads through the brain after the initial trauma--have completed clinical trials in Europe and the United States, and their results are being analyzed. The data should be available this fall, said Pitts.
Tirilazad (Freedox, Upjohn) blocks the effects of free radicals that pour into the brain cells for days, even weeks, after impact. Speaking to one benefit from the drug, Pitts noted: "Preclinical research showed that when vasospasm set in, due to compression from swelling or bleeding, treatment with tirilazad led to reopening of blood vessels and restoration of blood flow to the brain," thereby heading off irreversible damage. Thus "we're eagerly awaiting the data analysis from nearly 3,000 patients," he said.
Similarly, the antioxidant superoxide dismutase (PEG-SOD, Sanofi-Sterling), a free-radical scavenger that just completed phase III trials in thousands of patients here and abroad, is also being analyzed.
Perhaps even more promising, several speakers said, are the new glutamate blockers, also called excitatory amino acid inhibitors, which have passed U.S. phase II safety trials and are starting phase III trials in trauma centers here.
Pharmaceutical companies are racing to produce antiglutamate. Rhone-Poulenc Rorer and Burroughs Wellcome seem to be in the forefront at this time, according to Pitts.
A natural chemical, glutamate reaches levels up to 70% higher than normal in the traumatized brain, explained Tracy McIntosh, Ph.D., director of the head injury center, University of Pennsylvania, Philadelphia. …