Abstract 147: First-in-human Phase 1/2a Study Of Intracerebral Transplantation Using Embryonic-derived Neural Stem Cells (NR1) For Chronic Ischemic Stroke

Abstract

Introduction: Currently, no treatment exists to restore function in chronic stroke patients. Several prior intracerebral stem cell trials showed safety, but are not being further developed. Objective: NR1 is a human embryonic derived neural stem cell that improved motor-sensory function in rodent stroke models, and was expanded to produce GMP cryopreserved Cell Lots (P18). The aim is to assess the safety, tolerability and efficacy using intracerebral transplantation of NR1 cells in chronic stroke patients (NCT04631406). Methods: Inclusion Criteria: 18-75 yo; 6-60 months post-ischemic subcortical MCA stroke; mRS 3-4. Subjects are transplanted with NR1 (2.5M, 5M, 10M or 20M). Primary Outcomes: Adverse events 0-6 mos; Change in Fugl-Meyer (FM) motor score (maximum FM 100) compared to baseline at 6 months (≥10 points improvement considered “clinically meaningful”). Other outcomes: Barthel Index, NIHSS, Gait Speed test, mRS, MRI DTI, FLAIR, Resting State fMRI and [18F] FDG PET. Results: Six patients have been transplanted. Adverse events included headache and worsened speech, all resolving spontaneously. At 6 mos post-transplant: FM improved 15, 13 and 9 points in patients 1, 2 and 3 (all with faster gait); Barthel Index improved 5, 10 and 15 points. At 3 months FM improved 15 points (with faster gait) in patient 4. NIHSS improved 2 points in 2 patients and worsened 1 point in 1 patient. There was no change in mRS. All 6 patients demonstrated a new transient FLAIR signal in premotor cortex at d7, that resolved by 2 mos, which in prior studies was highly correlated with sustained neurologic recovery. An increase in regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuations (fALFFs) was observed in the sensorimotor network ipsilateral to the chronic infarction in patients with clinical improvement. Six additional patients are scheduled in the next 6 months. Conclusions: Intraparenchymal transplantation with NR1 cells in chronic stroke patients appears safe and well tolerated. Early results suggest improved motor function at 1-6 months post-implant.