Different River

”You can never step in the same river twice.” –Heraclitus

June 15, 2005

New Treatment for Stroke

Filed under: — Different River @ 3:35 pm

Here’s something which looks to me like unalloyed good news. AstraZeneca has a drug called Cerovive in Phase III clinical trials which seems to have great promise for treating ischemic stroke. (An “ischemic stroke” is cause by a blood clot in the brain which cust off the flow of blood to a part of the brain, thus depriving it of oxygen. This is as opposed to a “hemorrhagic stroke,” in which a blood vessel in the brain ruptures, damaging the brain by internal bleeding. About 85% of strokes are ischemic.)

Right now, the best treatment for ischemic stroke is a drug called tPA, which can break up the blood clot and stop further damage. There are two drawbacks with tPA: First, to be effective it has to be given within 3 hours of the stroke. Second, while it’s great for ischemic strokes, it can make a hemorrhagic stroke worse by inhibiting the clotting necessary to stop the internal bleeding. This means doctors have 3 hours from the time of the stroke — which means even less time from the time the patient arrives in the emergency room — to both figure out that it’s a stroke and what type of a stroke it is, and administer the tPA.

It turns out, however, that much of the damage is cause not by the oxygen deprivation directly,

But much of the damage happens when brain cells, starved of oxygen, start churning out compounds that can actually be toxic.

If all goes well, Cerovive will be able to stop this type of damage. Furthermore, it seems to be effective up to six hours after a stroke, rather than three — and better yet, it seems to be as safe as a placebo. If my understanding of all this is correct, this means that Cerovive could be administered as soon as a patient shows up with stroke-like symptoms, since it wouldn’t do any damage if it turned out to be a non-ischemic stroke or something other than a stroke.

This all started in one lab over twenty years ago:

he work that led to Cerovive began almost twenty years ago, in the lab of Robert Floyd, a chemist at the Oklahoma Medical Research Foundation. Floyd discovered a compound that seemed to limit the damage from ischemic strokes in lab animals. But the medicine had a potential for toxicity, and he spent years refining it before founding a company called Centaur. Rights to the drug were eventually purchased by Renovis.

Matthew Herper of Forbes reports that doctors are enthusiastic:

Doctors with no financial relationship to the drug’s makers say the news is a welcome surprise, as no other drug has ever shown a statistically significant benefit in preventing such injuries. Says Steven Rudolph, director of the Stroke Center at Maimonides Medical Center in New York: “Everything has been negative until now.”

“I’m surprised and encouraged,” says Marc Fisher, a professor of neurology at the University of Massachusetts Medical School. “I didn’t think it was going to be positive. This is really a good thing for the acute stroke field because it’s clearly a safe drug, and it’s a step forward for providing additional therapy.”

“It’s a very exciting time in stroke now,” says Maimonides’ Rudolph. “Stroke is not being viewed by the medical community as something hopeless. It’s an area of active innovation, and it’s an area of progress. That’s very exciting for us.”

Of course, this being Forbes, he also points out that a lot of money could be made from this:

Shares in Renovis, which licensed the drug to Astra and will receive royalties should it reach the market, shot up 86% to $12.64 on the news, giving the little company a market value of $312 million. Astra shares rose slightly in mid-day trading. The results must be confirmed in a second big trial, which is already ongoing, but doctors and the companies are cautiously optimistic. Cerovive could produce $1 billion in annual sales once it wins Food and Drug Administration approval.

Then again, it’s not like they aren’t doing anything for the money. Renovis claims on its web site:

The annual cost of stroke-related care in the United States exceeds $51 billion. More than two million strokes occur each year in the world’s major industrialized countries, about 700,000 of which occur in the United States.

So, this is a drug that could help millions of people avoid or reduce the brain damage caused by stroke, saving their lives, avoiding or reducing their disabilities, and saving everybody money while doing it.

What was that again about the evil, profit-hungy drug companies? ;-)

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