On 14 March, the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) authorised the use of the recombinant tissue plasminogen activator (rt-PA) alteplase (Actilyse, Boehringer Ingelheim) for the thrombolytic treatment of acute ischaemic stroke up to 4.5 hours after symptom onset, and after prior exclusion of intracranial haemorrhage. Previously, alteplase was authorised for a 3 hour treatment window.
The extended treatment window from 3 to 4.5 hours will allow a greater number of eligible patients to receive thrombolysis. Data from Rudd AG et al (Journal of Neurology, Neurosurgery and Psychiatry 2011; 82: 14-19) and Bembenek J et al (International Journal of Stroke 2010; 5: 430) suggest that extension of the licence has the potential to make alteplase treatment available to between 2–4.7% more people with acute stroke.
Paul Guyler, lead stroke clinician, Southend University Hospital NHS Trust and lead for Acute Stroke, Essex Cardiac and Stroke Network, UK, said: “The 4.5 hour approval will allow clinicians to treat more patients and therefore improve their clinical outcomes. We have made great strides in improving stroke services in the UK, but we must now consider the extended treatment window and adjust protocols so they continue to apply best practice for prompt diagnosis, assessment for eligibility, and delivery of thrombolysis.”
Martin James, consultant stroke physician, The Royal Devon and Exeter NHS Foundation Trust, and former president, British Association of Stroke Physicians, said: “Extending the licensed time window for thrombolysis treatment with alteplase to 4.5 hours from onset represents a major step forward in the treatment of acute ischaemic stroke. However, excitement at this significant advance is moderated by the widely held concern that by having more time in which to deliver treatment, clinicians may lose some of the sense of urgency that came with the previous tight 3 hour window. Our research has shown that if the time window extension results in even a small general delay for all treated patients, then the benefits from extension could be lost (James M et al, International Journal of Stroke, 2011; 6 (suppl 2): 4). Eliminating in-hospital delays to treatment, for example by using pre-alerts to stroke teams and radiology departments and rapid assessment protocols, is the most effective way to increase the number of patients who survive stroke free of disability.”
The revised alteplase licence indication is based on the results of the European Cooperative Acute Stroke Study (ECASS 3), a randomised, double-blind, placebo controlled trial published in the New England Journal of Medicine in 2008. ECASS 3 demonstrated that Actilyse can increase favourable outcomes with only minimal or no disability after an acute ischaemic stroke when administered in an extended time-window from 3 to 4.5 hours after symptom onset.