Strategy for Improving Stroke Treatment Response
Recruiting now Phase 2 NCT05948566
Run by Translational Sciences, Inc. · for 18 and older · All sexes
What this study is about
SISTER is a Phase-II, prospective, randomized, placebo-controlled, blinded, dose finding trial that aims to determine the safety and preliminary efficacy of TS23, a monoclonal antibody against the alpha-2 antiplasmin (a2-AP), in acute ischemic stroke.
Who can join (things the study team will check)
✅ You may be able to join if…
- Age 18 years and older
- Suspected anterior circulation acute ischemic stroke
- NIH Stroke Scale score ≥4 prior to randomization a. The participant must have a clearly disabling deficit if NIHSS is 4-5.
- Favorable baseline neuroimaging consisting of all of the following: i. Mismatch ratio of penumbra: core >1.2 ii. Mismatch volume >10 cc iii. Core <70 cc c. If CT hypodensity is present, then in the investigator's visual assessment, the total acute infarct volume combined area of (a) the CT hypodensity and (b) the perfusion-based core volume (CBF<30%) should be smaller than perfusion-based volume (area of Tmax>6s minus CBF<30%).
- ASPECTS of 6 or more on CT (or ASPECTS of ≥7 on MRI)
- Favorable perfusion imaging on CT perfusion (CTP)/MR-perfusion weighted imaging (PWI) consisting of all of the following:
- Able to receive assigned study drug within 4.5 to 24 hours of stroke onset or last known well.
- Able to receive assigned study drug within 120 minutes of qualifying perfusion imaging. *
- Informed consent for the study participation obtained from participant or their legally authorized representatives.
- Study drug administration is encouraged within 90 minutes after qualifying perfusion image but is allowed up to 120 minutes. After 120 minutes, another perfusion image to ensure that inclusion criteria are met is required.
🚫 You may not be able to join if…
- Received endovascular treatment with clot engagement.
- Patients who undergo groin puncture but clot engagement is not attempted due to spontaneous distal migration are permitted to be enrolled in the trial if all other eligibility criteria are met.
- Patients who undergo groin puncture but clot is not engaged due to reasons other than spontaneous distal migration are NOT permitted.
- Received or planned to receive intravenous thrombolysis.
- Pre-stroke modified Rankin score >2.
- Previous treatment with TS23 or known previous allergy to antibody therapy.
- Known pregnancy, women who are breastfeeding or plan to breastfeed within 3 months of receiving TS23 or have a positive urine or serum pregnancy test for women of childbearing potential.
- Known previous stroke in the past 90 days.
- Known previous intracranial hemorrhage, intracranial neoplasm, subarachnoid hemorrhage, or arterial venous malformation.
- Known active diagnosis of intracranial neoplasm.
- Clinical presentation suggestive of a subarachnoid hemorrhage, even if initial CT scan was normal.
- Surgery or biopsy of parenchymal organ in the past 30 days.
- Known trauma with internal injuries or persistent ulcerative wounds in the past 30 days.
- Severe head trauma in the past 90 days.
- Persistent systolic blood pressure >180mmHg or diastolic blood pressure >105mmHg despite best medical management.
- Serious systemic hemorrhage in the past 30 days.
- Known hereditary or acquired hemorrhagic diathesis, coagulation factor deficiency, or oral anticoagulant therapy with International Normalized Ratio (INR) >1.7.
- Platelets <100,000/mm3.
- Hematocrit <25 %.
- Elevated aPTT above laboratory upper limit of normal.
- Creatinine > 4 mg/dl, or patients receiving renal dialysis, regardless of creatinine.
- Received the following within the previous 24 hours:
- If patient received unfractionated heparin within the last 24 hours, the patient must have an aPTT within normal range prior to enrollment.
- Low molecular weight heparins such as Dalteparin, enoxaparin, tinzaparin in full dose within the previous 24 hours.
+ 6 more criteria — see the full checklist in the app.
Where this trial is running
- University of Alabama Hospital, Birmingham, Alabama, United States
- Banner University Medical Center, Phoenix, Arizona, United States
- Mayo Clinic Phoenix, Phoenix, Arizona, United States
- Banner University Medical Center - Tucson, Tucson, Arizona, United States
- UCSD Health La Jolla, La Jolla, California, United States
- Kaiser Permanente Los Angeles, Los Angeles, California, United States
- Sutter Medical Center, Sacramento, California, United States
- UCSD Medical Center- Hillcrest Hospital, San Diego, California, United States
- Hartford Hospital, Hartford, Connecticut, United States
- Yale New Haven Hospital, New Haven, Connecticut, United States
- Christiana Hospital, Newark, Delaware, United States
- UF Health Shands Hospital, Gainesville, Florida, United States
+ 40 more sites.
Who to contact
Rebeca Aragon Garcia, BS, CCRC · 9736688644 · aragonra@ucmail.uc.edu
It's completely normal to call and ask questions before deciding anything. Mention the study ID: NCT05948566.
Verify everything on the official ClinicalTrials.gov record. Page updated July 2026.
Beacon is an information tool, not medical advice. Whether a trial is right for you is a decision for you, your doctor, and the study team. Trial details come from the official registry, ClinicalTrials.gov, and may change — always confirm with the study team. Beacon collects no data about you: this page has no cookies, no accounts, and no tracking.