William Niehaus, MD, Associate Professor of Physical Medicine & Rehabilitation at the University of Colorado Anschutz, is a co-researcher on a groundbreaking clinical trial aimed at giving stroke survivors a second chance at recovery long after the initial healing window has passed.

The trial, called SuNR1se II (NR1-03), is part of a multi-site Phase 2B study led by researchers at Stanford University. CU Anschutz is now joining the effort, which explores the use of engineered stem cells to “reboot” the brain’s healing process 6-9 months, or even years, after an ischemic stroke.

“Traditionally, stroke patients who still need therapy after six months are told there’s not much more that can be done,” says Dr. Niehaus. “This study challenges that idea.”

How It Works

Rather than using a patient’s own cells, researchers inject a pre-engineered stem cell mixture into the brain near the damaged area (not directly into the stroke site), but into a nearby “transition zone.” This is done through a small hole drilled into the skull by a neurosurgeon.

These stem cells don’t replace brain tissue. Instead, they act like biological messengers, releasing growth factors and signals that encourage the brain to clean up damaged cells, promote new cell growth, stimulate blood vessel formation, and spark the brain’s own repair mechanisms.

This process known as paracrine modulation helps “prime” the brain to heal itself, potentially improving blood flow and restoring neural circuits.

Why CU Anschutz?

CU Anschutz is being added to the Phase 2B portion of the trial due to promising early results. The goal now is to expand the study to more sites and more patients, ensuring the treatment’s effects are consistent and repeatable. If successful, this could pave the way for a full Phase 3 trial, with CU Anschutz playing a key role.

You can learn more about the SuNR1se II (NR1-03) study using the below links:

SuNR1se II Clinical Trial on ClinicalTrials.gov

Understanding Clinical Trial Phases (FDA)