TBO-309 added to thrombectomy and carotid stenting for tandem occlusion stroke

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

This trial will test whether giving intravenous TBO-309 during thrombectomy and carotid stenting helps keep stents open and lowers bleeding risk in adults with acute ischemic stroke from tandem occlusion.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 78 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: ThromBio Pty. Ltd. (Industry-sponsored)
• Locations: 2 sites (Newcastle, New South Wales and 1 other locations)
• Trial ID: NCT06813651 on ClinicalTrials.gov

What this trial studies

Co-STAR is a multicenter, prospective, open-label Bayesian Phase 2 trial of adjunctive intravenous TBO-309 in adults with acute ischemic stroke due to tandem occlusion undergoing intracranial endovascular thrombectomy and acute extracranial carotid stenting. Participants receive a bolus and infusion of TBO-309 at one of three dose levels (30, 60, 120 mg) in addition to standard EVT and stenting. The primary composite endpoint combines avoidance of intra-procedural GPIIb/IIIa rescue therapy and acceptable rates of symptomatic intracranial hemorrhage. Patients are selected using CT perfusion criteria for salvageable brain tissue and must meet clinical stroke severity and pre-stroke function thresholds.

Who should consider this trial

Good fit: Adult patients (≥18 years) with acute ischemic stroke due to tandem occlusion who are eligible for intracranial thrombectomy and acute cervical carotid stenting, have salvageable brain tissue on CT perfusion (core <70 mL, mismatch ratio >1.8, absolute mismatch >15 mL), NIHSS >4, and pre-stroke mRS <4.

Not a fit: Patients with large established infarcts (greater than one-third MCA territory), severe pre-stroke disability (mRS 4–5), very low consciousness (GCS 3–5), uncontrolled hypertension, or other exclusion criteria are unlikely to benefit or are excluded from this approach.

Why it matters

Potential benefit: If successful, TBO-309 could keep carotid stents open without frequent use of potent rescue antiplatelet drugs and reduce hemorrhagic complications after thrombectomy.

How similar studies have performed: This PI3Kβ-targeted antiplatelet approach is relatively novel with limited clinical data in stroke, while GPIIb/IIIa inhibitors and other antiplatelet strategies have been used previously but carry higher hemorrhage risk.

Eligibility criteria

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

Where this trial is running

Newcastle, New South Wales and 1 other locations

• John Hunter Hospital — Newcastle, New South Wales, Australia (Recruiting)
• Royal North Shore Hospital — St Leonards, New South Wales, Australia (Not_yet_recruiting)

Study contacts

• Principal investigator: Ferdinand Miteff - Interventional Neurologist, RACP, CCINR — John Hunter Hospital, Newcastle, NSW Australia
• Study coordinator: Ferdinand Miteff - Interventional Neurologist, RACP, CCINR

Conditions Ischemic Stroke; Tandem Occlusion; Ischaemic stroke; Stenting; Endovascular thrombectomy; tandem occlusion