Abstract Body: Background and Aims: Whether emergency angioplasty for progressive stroke (PS) with severe intracranial artery stenosis (ICAS) can improve functional outcomes is unknown. We aim to assess the efficacy and safety of emergency angioplasty in treating patients with PS-ICAS.

Methods: MAGIC II is an investigator-initiated, adaptive, multicenter, prospective, randomized controlled, open-label, blinded endpoint (PROBE) trial (ChiCTR2400088214). Patients with PS attributed to severe ICAS (70-99%) within 24-72 hours of symptom onset will be screened for eligibility. Eligible participants are randomly assigned 1:1 to receive emergency angioplasty (with or without stenting) or only standard medical treatment. The primary outcome is the proportion of the 90-day modified Rankin Scale of 0-2. MAGIC II was designed to test a 15% difference (43% vs 28%) in the proportion of functional independence with a planned sample size of 388 subjects. After 50% of the planned sample size completes the study, an interim analysis will be conducted to determine the continuation of the study, and the final sample size will be re-calculated.

Results: This study has been approved by the Ethics Committee of Shenzhen Hospital of Southern Medical University and will receive approval from all participating centers. MAGIC II is expected to be conducted at ~30 stroke centers in China. When submitting this abstract, no participant is randomized, and the study is expected to be completed by 2030.

Conclusions: MAGIC II will provide robust evidence of emergency angioplasty for PS-ICAS in improving functional outcomes.