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Hello. My name is Dr. Mark Alberts. I am Professor of Neurology at Northwestern University and head of the stroke program at Northwestern Memorial Hospital in Chicago, Illinois. Welcome to this Medscape stroke update.
Today I would like to update you about an important, very recent ruling from the US Food and Drug Administration (FDA). Genentech, the makers of tPA (tissue plasminogen activator) for stroke, went to the FDA to try to get an expanded label indication to use intravenous (IV) tPA in patients with ischemic stroke during the 3- to 4.5-hour period. This request was based on the ECASS-3 trial (the third European Cooperative Acute Stroke Study), which we have discussed previously, as well as pooled registry data from Europe and from other studies. We do not know in great detail why the FDA turned down Genentech's application to expand the label window to up to 4.5 hours for IV tPA. We have heard that the FDA did not think the data were "compelling." This may mean that there was only 1 large, prospective, randomized trial instead of 2, which they usually require. It may relate to the fact that ECASS-3 was essentially conducted in Europe and there was no US trial to compliment it; [the reasons behind the decision] are unclear.
At this point, however, I know that I and many of my colleagues around the country, and certainly around the world, continue to use IV tPA up to a 4.5-hour time window. We await professional groups such as the American Heart Association, perhaps the American Academy of Neurology, perhaps the Brain Attack Coalition, to digest the FDA's ruling to learn more about the data and the reasoning behind this and to come out with a statement or guidance about what to do for patients up to the 4.5-hour time limit. At this point, in my opinion, I think that if we are going to treat people with IV tPA beyond the 3-hour time window, it seems reasonable and prudent to have the patient or the next of kin sign an informed consent indicating that this is not currently an FDA-approved treatment but it is recommended in 1 or more guidelines. When we get more information, we will have to see the reasoning behind this decision and see whether we should go forward in terms of continuing this therapy.
The other practical thing to consider is that IV tPA at either a 3- or a 4.5-hour time window is relatively easy and straightforward to use. The only other practical treatment would be some type of endovascular therapy. This would require transportation of the patient to a comprehensive stroke center where endovascular therapy is available. It could mean sedation and intubation in many cases, and it could mean a time delay to get the patient to the endovascular suite, gain access, get the catheter into the brain, and then perform the procedure.
At the end of the day, IV tPA at [up to] 4.5 hours is certainly the most rapid therapy we can offer in the vast majority of settings. Whether it is the best, the safest, and the most effective treatment remains to be seen.
Thank you very much for attending this Medscape stroke update.
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