510 Dopaminergic Neuronal Cell Therapy for Parkinson’s Disease: Results From a Phase 1 Study of Bemdaneprocel

INTRODUCTION: None of the available therapies for PD directly address the loss of dopaminergic neurons. Bemdaneprocel is an investigational cellular therapy composed of midbrain dopaminergic neuronal cells derived from human embryonic stem cells. METHODS: In this open-label study 12 subjects have received 1 of 2 doses of bemdaneprocel to the putamen bilaterally, along with a 1-year immunosuppression regimen. Safety and tolerability have been assessed, along with assessments of engraftment and clinical impact. RESULTS: At screening, the average age was 66.4 yrs and the mean time since diagnosis was 9.1 yrs. All subjects presented at screening with a Hoehn and Yahr stage of 2 in the on-medication state. The mean MDS-UPDRS part III score was 46.6 (15-73) when assessed in the off-medication state, and patients presented with 4.3 (1.4-6.2) average daily hours of OFF time as assessed by PD diaries. In both cohorts, the safety profile is favorable with the vast majority of reported treatment-emergent AEs being mild to moderate. All but one AE deemed potentially related to the intervention were attributed to the immunosuppression regimen. There were no AEs reported as possibly related to the cell therapy. Patients enrolled in both cohorts to date have demonstrated clinical improvement as measured by the MDS-UPDRS, PD diaries, PDQ-39, and others. F-DOPA PET imaging supports evidence of engraftment, survival and functionality of the cells at 1 year. CONCLUSIONS: Results from at least 1 year of follow-up in this phase 1 study will be presented. An acceptable safety profile, evidence of sustained engraftment, and positive exploratory clinical outcomes in this study support further investigation of bemdaneprocel for the treatment of PD. Unpublished data, will be partly shown in a poster at MDS