A long-term follow-up of safety and clinical efficacy of NTCELL® [Immunoprotected (Alginate-encapsulated) porcine choroid plexus cells for xenotransplantation] in patients with Parkinson's disease

Introduction: In 2019, we published the results of a Phase IIb randomized controlled trial of putaminal encapsulated porcine chomid plexus cell (termed NTCELL) administration in patients with Parkinson's disease. This study failed to meet its primary efficacy end-point of a change in UPDRS part III score in the 'off state at 26-weeks post-implant. However, a number of secondary end-points reached statistical significance. We questioned whether with longer follow-up, clinically significant improvements would be observed. For this reason, we decided to follow-up all patients periodically to week 104. Herein, we report the results of this long-term follow-up. Methods: All 18 patients included in the original study were periodically re-assessed at weeks 52, 78 and 104 post-implant. At each time-point, motor and non-motor function, quality of life and levodopa equivalent daily dose was assessed using a standardized testing battery. Results: At week 104, no significant differences in UPDRS part III scores in the 'off state were observed in any of the treatment groups compared to baseline. Only a single serious adverse event - hospitalisation due to Parkinson's disease rigidity not responding to changes in medications was considered potentially related to the implant procedure. There was no evidence of xenogeneic viral transmission. Conclusion: Un-blinded, long-duration follow-up to week 104 post-implantation showed no evidence that putaminal NTCELL administration produces significant clinical benefit in patients with moderately advanced Parkinson's disease.

Automated summary

The long-term follow-up study of putaminal NTCELL administration in patients with Parkinson's disease showed no significant clinical benefit up to week 104 post-implantation. Only one serious adverse event potentially related to the implant procedure was reported in the study.