Hemophilia Drug Fights Most Lethal Form of Stroke
It's the first agent to prove effective against hemorrhagic attack, experts say
WEDNESDAY, Feb. 23, 2005 (HealthDay News) -- Positive results from a major international trial suggest a drug used to treat hemophilia may cut deaths and disability from a particularly lethal type of stroke.
Patients given the drug, called recombinant activator factor VII (rFVIIa), within four hours of a hemorrhagic stroke had a significantly increased chance of survival and suffered less disabling brain damage than those not given the treatment, according to a report in the Feb. 24 issue of the New England Journal of Medicine.
"These results are to be celebrated because, with future studies, we are on the brink of the first targeted therapy for cerebral hemorrhages," said Dr. Lewis B. Morgenstern, director of the stroke program at the University of Michigan Health System and co-author of an accompanying editorial in the journal.
Burst blood vessels are responsible for just 10 percent to 15 percent of strokes; the rest are caused by clots that block blood vessels in the brain. However, more than 60 percent of patients who suffer hemorrhagic strokes die within a year, despite the best treatments available now. Many of those deaths occur within the first hours following the stroke.
It was the memory of such deaths that prompted this trial, said Dr. Stephan A. Mayer, an associate professor of neurology and neurosurgery at Columbia University Medical Center, in New York City.
"I would be called to the emergency room to see a patient with an acute cerebral hemorrhage," Mayer said. "I would sit and watch them go down the drain before my eyes, vomiting and sweating before they went into a coma. It was clear that many were experiencing active bleeding into the brain."
Mayer's attention was caught by reports of rFVIIa, marketed in the United States for treatment of hemophilia under the brand name NovoSeven by the Danish pharmaceutical giant, Novo Nordisk. The drug helps fight the blood disorder because it improves blood's clotting ability, stanching the uncontrolled bleeding that imperils hemophiliacs.
Mayer had the idea that the drug "could take a normal coagulation system and supercharge it, so I saw the potential as an ultra-early treatment to arrest active bleeding in the brain."
He called Novo Nordisk to propose a trial, "and they flew someone over from Copenhagen right away," Mayer said. He described what followed as "an ideal example of how academia and industry can work together."
The trial included 399 stroke patients treated at 73 sites in 20 countries. Some were given a placebo, while others received different doses of the rFVIIa added in with their treatment.
By 90 days post-stroke, patients who got rFVIIa benefited from a 38 percent drop in mortality compared to patients who did not receive the drug. Furthermore, close to three times more patients using rFVIIA (24 percent) survived their stroke with no major neurological damage, compared to those on placebo (8 percent).
In general, patients who got the largest dose of rFVIIa did best, although there was an increased risk of heart attack and blockage of brain arteries in high-dose patients. Those problems call for further trials before the treatment can be approved for general use, Morgenstern said.
Still, the possibility of an effective treatment for hemorrhagic stroke may soon give physicians a new, viable option when it comes to treating these patients, he said. Right now, "physicians tend to give up early on patients with intracerebral hemorrhage," according to Morgenstern. "Doctors say there is a lot of blood in the brain, and families agree to withdraw care."
"The whole idea of trying to treat patients with stroke is relatively new," Mayer said. "In 30 years of research trying to find treatments we had only one success -- tissue plasminogen activator (tPA) for ischemic stroke," he said.
Timely use of tPA has improved survival of individuals who suffer strokes caused by ischemia (blocked arteries) by about a third, Mayer said.
A new trial aimed at getting U.S. approval of routine use of rFVIIa will soon begin, he said. It is expected to take about two years, but there is nothing to prevent physicians from using the drug "off label" to treat hemorrhagic strokes, Mayer said.
Mayer and Morgenstern agreed that stroke treatment is in a revolutionary period, with more medical centers establishing units devoted to the problem. The key issue, they said, is that treatment must start as quickly as possible. As Morgenstern said, "time is brain."
"This is a real struggle to end decades of therapeutic nihilism," Mayer said. "That is what is changing."
The warning signs and treatment of stroke are explained by the American Stroke Association.