About SB623

SB623 is a proprietary, cell-based investigational product made from modified and cultured adult bone marrow-derived mesenchymal stem cells that undergo temporary genetic modification. Implantation of SB623 cells into injured nerve tissue in the brain is expected to trigger the brain's natural regenerative ability to recover lost motor functions.

Target disease

Clinical trial results

STEMTRA was a 12-month, Phase 2, randomized, double-blind, surgical sham-controlled, global trial evaluating the efficacy and safety of SB623 compared to sham surgery in patients with stable chronic neurological motor deficits secondary to TBI. In this study, SB623 cells were implanted directly around the site of brain injury.

To be eligible for this trial, patients (ages 18-75) had to be at least 12 months post-TBI and had a Glasgow Outcome Scale extended (GOS-E) score of 3-6 (e.g., moderate or severe disability). Patients must also had to be able to undergo all planned neurological assessments and have had no seizures in the prior three months. The primary endpoint was mean change from baseline in Fugl-Meyer Motor Scale (FMMS) score which was used to measure changes in motor impairment at six months after treatment with SB623 cells. The STEMTRA trial enrolled 61 patients from 13 surgical and 18 assessment sites in the U.S., Japan and Ukraine.

In this study, SB623 met its primary endpoint, with patients treated with SB623 achieving an average 8.3 point improvement from baseline in the FMMS, versus 2.3 in the control group, at 24 weeks (p=0.040). Of patients treated with SB623, 18 (39.1%) reached a 10 or more point improvement of FMMS compared to one control patient (6.7%; p=0.039). No new safety signals were identified. The most commonly reported adverse event were headaches.


  • Mesenchymal Stromal Cells to Treat Brain Injury

    Tate CC and Case CC
    Chapter in "Neurological Disorders", InTech, 2012

  • Transplanted Mesenchymal Stem Cells Aid the Injured Brain through Trophic Support Mechanisms

    Tate CC and Case CC
    Chapter in "Stem Cells and Cancer Stem Cells, Vol 4", M.A. Hayat (Ed), 2012