Trial of EXenatide in Acute Ischaemic Stroke

Overview: Elevated blood glucose levels are common in many acute diseases, resulting in worse clinical outcomes. Hyperglycaemia in acute ischaemic stroke (post-stroke hyperglycaemia [PSH]) occurs in up to 50% patients, reduces the efficacy of stroke thrombolysis with increased risk of haemorrhage, increases infarct size, and results in worse clinical outcomes and death. Insulin-based therapies have not proved beneficial in treating PSH: they are difficult to implement and maintain, cause frequent hypoglycaemia, may cause increased infarct size, and do not reduce mortality or improve clinical outcomes. An alternative, simple to use, treatment for PSH may therefore have a significant impact not only for acute stroke care, but in other acute diseases.

Pilot data: Exenatide is a commonly used diabetes drug (a synthetic glucagon- like peptide-1 receptor agonist) that increases insulin secretion. Importantly, this action is glucose dependent - as blood glucose levels decrease, its stimulatory effect on insulin secretion subsides, with a very low risk of hypoglycaemia. A small randomised pilot study of 17 consecutive, unselected patients (ie. regardless of their admission glucose level) with acute ischaemic stroke compared subcutaneous exenatide 5μg for 5 days with routine standard of care. Overall, blood glucose levels remained consistently lower (and less variable) in the exenatide group, and most noticeably in those stroke patients with known diabetes. Exenatide was safe and well tolerated by all patients, with no symptomatic hypoglycaemia.

Trial design: TEXAIS is a 3 year Phase 2, multi centre, prospective, randomised, open label, blinded end-point (PROBE) trial comparing Exenatide to Standard of Care. The sample size is 528 patients (264 in each arm).

Intervention: Treatment arm will receive Exenatide (Byetta) 5μg subcutaneously twice daily for five days, commencing within 9 hours of symptom onset. Stroke onset time for wake-up strokes is taken as mid-point between going to bed, and waking up. Antiemetic therapy (metoclopramide or ondansetron) will be commenced with the first dose of Exenatide. In patients receiving tPA, Exenatide will be given alongside, or as soon as possible, following tPA administration (within 60 minutes). Diabetic patients already on oral agents and/or insulin may continue these (as per standard practice) in addition to Exenatide. Continuous glucose monitors (CGMs) will track the intra-day dynamic variability of glucose in acute stroke.

Translation: TEXAIS is a simple, practical, study that can enrol all patients with ischaemic stroke, regardless of admission blood glucose level, regardless of stroke severity, with no target glucose level, and with low risk of hypoglycaemia.