Safety, Tolerability and Efficacy of Adjunctive TBO-309 in Reperfusion for Stroke With Tandem Occlusion

Inclusion Criteria: 1. Patient aged 18 years or more 2. Patient has an AIS due to tandem occlusion, including large vessel occlusion (LVO) within the intra-cranial anterior circulation and presumed atherosclerotic occlusion of the cervical internal carotid artery origin 3. CT perfusion indicates the presence of salvageable brain tissue, defined as ischaemic core \<70mL with a mismatch ratio \>1.8 and absolute mismatch \>15mL. 4. Patient has at least a mild grade of neurological impairment (NIHSS \>4) 5. Patient has an estimated pre-stroke mRS of less than 4 Exclusion Criteria: 1. Patient is considered unlikely to benefit from study intervention defined by one of the following: 1. Advanced dementia 2. Severe pre-stroke disability (mRS score 4-5) 3. Glasgow Coma Score (GCS) 3 to 5 4. Evidence of a large well-defined ischaemic lesion measuring more than one third of the middle cerebral artery (MCA) territory 2. Uncontrolled hypertension (SBP \>180 or DBP \>110, refractory to medical therapy) 3. Intracranial haemorrhage within the last 90 days 4. Myocardial infarction or stroke within the last 30 days 5. Patient has an underlying disease process with a life expectancy of \<90 days 6. Known treatment with anticoagulants 7. Known severe liver disease 8. Known bleeding disorder 9. Cardiopulmonary resuscitation or arterial puncture at non-compressible site or lumbar puncture within 7 days 10. Another medical illness or social circumstance that may interfere with outcome assessments and follow-up 11. Known or suspected pregnancy 12. Patients currently participating in another interventional clinical trial 13. Informed consent unable to be obtained from the patient or their Person Responsible/Medical Treatment Decision Maker prior to study interventions