International Stroke Conference
February 6–8, 2019
Burton J. Tabaac, MD
Presenter: Mark Parsons, MD, PhD, FRACP — “tNK Is Ready for Prime Time”
This speaker argued that tenecteplase is the future of IV lysis. Tenecteplase is a genetically modified version of alteplase with an increased half life. Notably, tNK has been successfully used for myocardial infarction for decades, essentially replacing tPA. A phase II randomized trial comparing tNK and tPA (NEJM 2012) identified patients with LVO (large vessel occlusion) who benefited from reperfusion with tNK as compared to a relative lack of reperfusion with tPA. A phase 3 study currently being completed, TASTE, is comparing tNK and tPA. There is evidence to show that tNK has been more useful in drip and ship cases because tenecteplase does not require an hour long infusion following a bolus dose (as is required with tPA). Notably, using tNK instead of tPA will significantly reduce cost and decrease the risk of hemorrhage, and is more effective prior to thrombectomy.
Presenter: James C. Grotta, MD — “Stick with the Tried and True rtPA for Now”
Defending tPA, the presenter suggested evidence that the time to initiate bolus of tNK is longer than the time to initiate tPA. The only FDA-approved thrombotic is tPA given IV within 3 hours of symptom onset. The speaker suggested that instead of implementing a new thrombolytic, practitioners should aim to deliver and treat with the current therapy faster. “We don’t need something as good as tPA. … We need something better than tPA.” The NOR-TEST trial showed non-superiority of tNK over tPA. The most potent way to improve tPA outcomes is to give it faster. The presenter argued that ultra-early treatment should be our main goal.
Presenter: Shelagh B. Coutts, MD — “tNK Is Ready for Prime Time – Rebuttal”
The AHA stroke guidelines 2018 detail that tenecteplase might be considered as an alternative to alteplase in patients with minor neurological impairment. The speaker highlighted arguments for tNK: Single bolus is much easier to administer, there are better recanalization rates, lower ICH rates, and it is cheaper in most of the world. A formal meta-analysis of tNK vs tPA showed non-inferiority of tNK, with similar disability free rates (mRS of 0-1) at 90 days. There is most evidence for administering a dose of 0.25mg/kg. The presenter suggested that tNK may be safer and more efficacious, is just as good as tPA, and is easier to use.
Presenter: Christopher A. Lewandowski, MD — “Stick with the Tried and True rtPA for Now – Rebuttal”
In a final rebuttal, this speaker highlighted the perspective of an emergency medicine physician. Treating both patients with acute MI and acute stroke, the presenter pointed out that the two pathologies are not the same. A theme of this talk aimed to underscore than tNK is non-superior (and non-inferior) to tPA in terms of efficacy. Being equivalent, the EXTEND-IA tNK trial showed there is no difference in IV to IA time. However, the dose of tNK is not yet established, and emergency medicine physicians prefer medications with short half lives. The speaker asked if a patient deteriorates, and there is no infusion to turn off, with no reversal agent available, what is the next course of action? Offering a concession, it is suggested that tNK may be useful for patients presenting later than 4.5 hours from last known normal, and for patients with LVO. The future may trend towards implementing tNK over tPA, but we will have to wait and see!