ABSTRACT NUMBER: ESOC2026A419 FINAL RESULTS OF THE PHASE II ARG-007-002 SEANCON TRIAL OF ARG-007 IN ACUTE ISCHAEMIC STROKE PATIENTS UNDERGOING ENDOVASCULAR THROMBECTOMY

Abstract Background and aims The Phase II SEANCON study aimed to evaluate the safety, tolerability, and preliminary efficacy of a single intravenous dose of ARG-007 (a cationic poly-arginine peptide with cerebroprotective effects in preclinical models) in patients with AIS undergoing revascularisation by endovascular thrombectomy. Methods SEANCON was a multicentre, randomized, double-blind, placebo-controlled trial conducted at 10 Australian stroke centres. Large vessel occlusion AIS patients, eligible for endovascular thrombectomy within 24 hours of symptom onset, were enrolled and randomized 1:1 to ARG-007 or placebo. Enrolment criteria included baseline NIHSS > 5 and prestroke mRS 0–3, site-assessed ASPECTS 0–5 were excluded. All participants received standard-of-care thrombectomy with/without intravenous thrombolysis. The primary outcomes were measures of safety. The secondary outcome was infarct volume at 48 hours. Results 93 participants were randomized (ARG-007 n = 46; placebo n = 47). Follow-up to day 90 was completed by 77 (83%) participants; 16 (17%) participants died before day 90. There was no significant difference between treatment groups in treatment-emergent adverse events (risk ratio [RR]:1.02, 95% CI: 0.91-1.15; P = 0.72), mortality at day 90 (RR:1.70, 0.67-4.30, P = 0.26), symptomatic intracranial hemorrhage (RR:4.09, 0.47-35.2, P = 0.20), worsening of the index stroke (RR:2.04, 0.76-5.52, P = 0.16), or functional independence at day 90 (mRS 0-2: odds ratio 0.92, 0.36-2.37, P = 0.86). Infarct volume at 48 hours did not differ significantly between groups (ratio (adjusted): 1.65, 0.97–2.81, P = 0.065). A potential subgroup signal favoring ARG-007 was observed in participants with poor collateral circulation. Conclusions In AIS patients, ARG-007 was safe and well tolerated. Conflict of interest David Blacker: Shareholder in Argenica Therapeutics Ltd and is paid a consultancy fee as Chair of the Argenica Clinical Advisory Committee. All other authors have nothing to disclose.