NCT05948566 · Translational Sciences, Inc.
Strategy for Improving Stroke Treatment Response
(SISTER)
What this study is about
SISTER is a Phase-II, forward-looking, randomly assigned, compared against an inactive treatment, blinded, dose finding trial that aims to determine the safety and preliminary effectiveness of TS23, a monoclonal antibody against the alpha-2 antiplasmin (a2-AP), in acute ischemic stroke.
View original scientific description
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.
Interventions
BIOLOGICAL
TS23
Monoclonal antibody
Primary outcome measures
The proportion of patients with ANY intracerebral hemorrhage (ICH)
Time frame: At 30 (+/- 4) hours after study drug
Any ICH visualized on the follow-up CT scan
Stroke severity as measured by the National Institutes of Health Stroke Scale (NIHSS)
Time frame: At 30 (+/- 4) hours after study drug
NIHSS is a stroke severity score that ranges from 0 to 42, with higher numbers indicating a more severe stroke. The NIHSS will be adjusted for the baseline value in analysis.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Age 18 years and older 2. Suspected anterior circulation acute ischemic stroke 3. NIH Stroke Scale score ≥4 prior to randomization a. The participant must have a clearly disabling deficit if NIHSS is 4-5. 4. Favorable baseline neuroimaging consisting of all of the following: a. ASPECTS of 6 or more on CT (or ASPECTS of ≥7 on MRI) b. Favorable perfusion imaging on CT perfusion (CTP)/MR-perfusion weighted imaging (PWI) consisting of all of the following: i. Mismatch ratio of penumbra: core \>1.2 ii. Mismatch volume \>10 cc iii. Core \<70 cc 5. Able to receive assigned study drug within 4.5 to 24 hours of stroke onset or last known well. 6. 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
Where
- Birmingham, Alabama
- Phoenix, Arizona
- Tucson, Arizona
- La Jolla, California
- Los Angeles, California
- Sacramento, California
- San Diego, California
- Hartford, Connecticut
- New Haven, Connecticut
- Newark, Delaware
- Gainesville, Florida
- Miami, Florida
And 36 more locations — see the full list below.
Collaborators
University of Cincinnati, National Institute of Neurological Disorders and Stroke (NINDS), Medical University of South Carolina, University of Arizona
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jun 2, 2026 · Source of record for eligibility and locations