Intra-Arterial Bevacizumab as an Adjunct to Middle Meningeal Artery Embolization for Chronic Subdural Hematoma

This is a Phase 1, open-label, single-center, dose-escalation study evaluating the safety and tolerability of intra-arterial bevacizumab (IA-BEV) given as an adjunct to middle meningeal artery embolization (MMAE) in adults with non-surgical chronic subdural hematoma (cSDH). Up to 18 participants who are already scheduled to undergo MMAE as standard of care will receive a single dose of bevacizumab, delivered directly into the middle meningeal artery immediately before embolization, during the same procedure. Three dose levels (2.0, 3.5, and 5.0 mg/kg) will be tested using a standard 3+3 dose-escalation design to identify the maximum tolerated dose. The study will also collect imaging and blood biomarker data to help understand which patients may benefit most from this combined treatment approach.

Inclusion Criteria: * Age 18-85 years * Scheduled to undergo MMAE as standard of care for cSDH, no concurrent surgical evacuation planned (prior surgery for the target cSDH allowed if ≥14 days elapsed) * Radiographically confirmed cSDH meeting specified unilateral/bilateral density criteria * cSDH volume 20-100 cc * Midline shift \35s, platelets \220 or DBP \>120, or IV antihypertensive need within 24h pre-procedure) * Thromboembolic event within 6 months (DVT, PE, TIA, stroke) * Contraindication to VTE prophylaxis * eGFR \