Abstract A070: Human Neural Stem Cell Line NSI-566 Provides Years of Stable Motor Gain from Chronic Hemiparesis due to Ischemic Stroke

NSI-566 is a primary allogeneic human neural stem cell line derived from a single fetal CNS. Here we present 7 years of follow-up data from a double-blind, randomized, sham-surgery controlled Phase 2a clinical study of NSI-566 intracerebral transplantation in chronic ischemic stroke patients with stable hemiparesis for 6-24 months. Method: A total of 23 patients were randomized into 2 groups where one received 7.2x10 7 NSI-566 cells in about 45 cell deposits around the 3D perimeter of MRI-defined stroke cavity in a single surgery (n=12) and the other received sham surgery (n=11) who were offered NSI-566 transplantation 12 months later. Changes in their upper and lower motor functions were assessed by Fugl-Meyer Motor Score (FMMS, normal=100) by independent blinded stroke rehabilitation specialists. Final follow-up of all available patients was carried out at 48-84 months after the NSI-566 transplantation. Results/Conclusions: Altogether 19 patients received a single dose of NSI-566 of whom 18 completed at least 12 months of follow-up. The degree of motor improvement by FMMS highly correlated with the degree of stroke cavity filling by new tissue from the 566 transplantation. Eight 566 patients showed no filling of the cavity in MRI and no significant change in FMMMS scores for the entire duration. Seven patients had the new tissue primarily within the cavity itself with little merging/integrating with the brain tissues surrounding the cavity. These patients gradually gained partial motor function with clinically meaningful 14-23 points of change from baseline several years after the transplantation. The slow motor gain presumably corresponds to the period for the new tissue from transplantation to integrate with the host brain circuitry. The remaining three patients showed almost complete filling of their cavity with new tissue by 12 months and gained 25-51 FMMS points from baseline of motor improvement that reached 76-87% of normal motor function in combined lower and upper limb movements. The upper extremity function improved up to 36 points and reached up to 89% of normal. The lower extremity function improved up to 8 points and reached up to 82% of normal. The motor improvement of patients who received NSI-566 (n=18) were statistically significant by 2-way ANOVA analysis (p<0.001) against the blinded Sham (n=11). The maximum motor improvement gained remained stable at their final follow-up visit, 74-84 months since the cell transplantation.