1058 Long Term Follow Up of Stem Cell Transplantation for Thoracic Spinal Cord Injury

INTRODUCTION: We previously reported 2-year follow up, as well as safety and improvement in motor and sensory scores using neural stem cell line (NSC) NSI-566 in thoracic spinal cord injury (SCI) patients. METHODS: A total of four subjects received NSI-566 spinal cord implantation. Prospective data have been collected including ISNCSCI scores, functional and pain surveys, SCIM scores, electromyography (EMG), and Brain Motor Control Assessment (BMCA). RESULTS: Compared to neurological level of injury, motor score, and sensory score at two years after cell grafting, no further improvements occurred across all patients at 60-months. Subject 001 experienced a decline from two levels of improvement (two years) to one level of improvement at study completion (five years). While improvements in average motor zone of partial preservation (ZPP) was recorded across all patients at 18 months, the final average motor ZPP declined to pre-operative baseline across all patients. At five years, two patients had overall decreased pain scores post-operatively that was sustained from the 24-month data. In one subject (T8 injury), EMG showed improvement to T10 at 2 years, and improved further to T12 at 60-months. In another patient (T7 injury), BMCA showed newly developed muscle responsiveness in lower limbs at 60-months, new from 24-months. A third subject (T5 injury) achieved positive BMCA data at 42-months, which showed suggestion of newly developed muscle responsiveness in lower limbs to reinforcement maneuvers. CONCLUSIONS: Our current analysis of 60-month clinical data demonstrate that injection of NSI-566 in thoracic SCI patients is safe with no detectable side effects identified, as well as some further improvements from 24-months. This phase 1 data of proof of safety and positive data, albeit small, will continue into Phase 2 trial, poised to start in Q3 2024.