Abstract Number: Esoc2026lb177 Illuminate: A Randomized, Double-Blind Phase Ii Trial of Il-6 Receptor Inhibition With Tocilizumab in Acute Ischemic Stroke Undergoing Endovascular Thrombectomy

Abstract Background and aims Endovascular thrombectomy (EVT) has substantially improved outcomes in acute ischemic stroke (AIS); however, many patients do not achieve functional independence. Secondary brain injury related to post-ischemic and ischemia–reperfusion–associated neuroinflammation is increasingly recognized as a contributor to infarct expansion after EVT. Interleukin-6 (IL-6) is a central inflammatory mediator in AIS and is consistently associated with infarct growth and unfavorable outcomes. IL-6 receptor inhibition with tocilizumab has demonstrated neuroprotective effects in experimental stroke models and early clinical studies. The ILLUMINATE trial is designed to evaluate whether IL-6 receptor blockade reduces infarct growth in patients with AIS undergoing EVT. Methods ILLUMINATE is an ongoing multicentre, randomized, placebo-controlled, double-blind phase II trial. Adults with AIS scheduled for EVT are randomized 1:1 to receive a single intravenous infusion of tocilizumab or placebo administered before or during EVT. The primary endpoint is infarct growth, defined as the change in diffusion-weighted imaging lesion volume between MRI performed within 8 hours after EVT and at 72 hours. Secondary endpoints include NIHSS, functional outcomes, health-related quality of life, brain-derived tau, inflammatory biomarkers, and safety outcomes including symptomatic intracranial haemorrhage, infections, and mortality up to 90 days. Results Recruitment is ongoing at centres in Norway and Denmark. Updated enrollment numbers will be presented. Conclusions LLUMINATE addresses a mechanistically defined and clinically relevant target in AIS. By combining standardized MRI-based infarct growth assessment with clinical and biological endpoints, the trial aims to generate evidence on IL-6–mediated neuroinflammation and inform adjunctive strategies in patients undergoing EVT. Conflict of interest