Mitchell S.V. Elkind, M.D., is American Heart Association president-elect, chair of the Advisory Committee of the American Stroke Association — a division of the American Heart Association and professor of neurology and epidemiology at Columbia University New York. 

copyright American Heart Association

"I think that the extend IATMK part two trial really extends, if you will the results of other trials from the extend group of investigators, which is largely a group from Australia and New Zealand. The extend trials, the extend IA trial was one of the first to show the benefits of using endovascular therapy on top of intravenous thrombolytic therapy for patients with stroke. And in fact, the initial trial showed such a big benefit that they only needed about 70 patients to demonstrate and effect and in that trial, they use TPA or alteplase but in a subsequent trial, the extend IATMK trial, they substituted tenecteplase for alteplase in half the patients and did a randomized trial of that comparison. 

And they found that there was a big benefit to using tenecteplase instead of alteplase for patients who are undergoing endovascular therapy with a stem retriever. So the dose of tenecteplase used in that trial was point two five milligrams per kilogram. And in this trial that's being presented at the ISC now, they tested whether a higher dose of tenecteplase would be even more effective at improving recapitalization and outcomes after acute stroke in patients with large vessel occlusion who are undergoing endovascular treatment. 

And essentially what they found what was that, there was no clear benefit of using a higher dose of tenecteplase, so the point four milligram dose patients did not do better than those who got point two five milligrams, and there in fact, may have been an increase in risk of bleeding as well. So I think the study really kind of settles the dose that might be used of tenecteplase, when used together with endovascular therapy, at point two five milligrams per kilogram. 

It's interesting that this trial is being published and, you know, finds these results for tenecteplase. Tenecteplase is an exciting drug because it's easier to use in many ways than alteplase. It's a modified form of TPA, and can be given in a single bolus, you know, at one point in time, instead of the extended period of one hour, that we use for intravenous TPA. It's not used much in the United States though, we still, I think most gastroenterologists in the US still use alteplase and that's because other trials have been a little bit more equivocal, about whether tenecteplase is in fact better than TPA. And so, although there does seem to be evidence here of its benefit in this particular setting together with endovascular therapy, it's not clearly going to be used routinely in at least in the United States."