Cell therapy for chronic TBI: interim analysis of the randomized, controlled, double-blind STEMTRA trial

Objective: To determine if chronic motor deficits secondary to traumatic brain injury (TBI) can be improved by implantation of allogeneic modified bone marrow-derived mesenchymal stromal/stem cells (SB623).

Methods: This 6-month interim analysis of the 1-year double-blind, randomized, surgical sham-controlled, Phase 2 STEMTRA trial (NCT02416492) evaluated safety and efficacy of the stereotactic intracranial implantation of SB623 in patients with stable chronic motor deficits secondary to TBI. Patients in this multi-center trial (N=63) underwent randomization in a 1:1:1:1 ratio to 2.5x106, 5.0x106, 10x106 SB623 cells or control. Safety was assessed in patients who underwent surgery (N=61), and efficacy in the modified intent-to-treat population of randomized patients who underwent surgery (N=61; SB623=46, control=15).

Results: The primary efficacy endpoint of significant improvement from baseline of Fugl-Meyer Motor Scale score at 6 months for SB623-treated patients was achieved. S...