Bayer AG and its subsidiary BlueRock Therapeutics announced positive data from their Phase I clinical trial of bemdaneprocel (BRT-DA01), an investigational stem cell-derived therapy for Parkinson's disease. The trial met its primary endpoint, demonstrating safety and tolerability of bemdaneprocel in all 12 participants across low and high dose cohorts over one year. The data were presented at the International Congress of Parkinson’s Disease and Movement Disorders in Copenhagen, Denmark.
Safety and Tolerability
The Phase I open-label study reported no serious adverse events (SAEs) related to bemdaneprocel. Two SAEs, one seizure attributed to the surgical procedure and one COVID case, were reported but resolved without complications. This outcome is crucial as it establishes the initial safety profile of this novel cell therapy in a patient population vulnerable to complications.
Evidence of Cell Survival and Engraftment
18F-DOPA PET imaging scans provided evidence of cell survival and engraftment in both the low and high dose cohorts. This imaging technique visualizes dopaminergic activity in the brain, confirming that the transplanted cells are surviving and integrating into the neural circuitry. At diagnosis, it is estimated that patients have already lost 50-80% of their dopaminergic neurons. Bemdaneprocel (BRT-DA01) is designed to replace the dopamine producing neurons that are lost in Parkinson’s disease.
Clinical Improvements
Exploratory clinical endpoints showed improvements in both cohorts, with the high dose cohort exhibiting greater gains. Using the Hauser Diary, participants in the high dose cohort showed a median improvement of 2.16 hours in time spent in the “ON” state without troubling dyskinesia compared to baseline after one year. Time spent in the “OFF” state showed a corresponding median decrease of 1.91 hours after one year. In the high dose cohort, a one-year measurement using MDS-UPDRS Part III (measured in the “OFF”-medication state) showed a median reduction of 13.0 points compared to baseline.
Expert Commentary
"The data from this Phase I open label study are extremely encouraging," said Claire Henchcliffe, MD, chair of the UCI School of Medicine Department of Neurology at the University of California, Irvine and one of the study’s Principal Investigators. "While this is a small open-label study, meeting the study’s primary objective for safety and tolerability along with initial improvements seen in clinical outcomes represents a great step forward. The hope now is that these trends continue and translate into meaningful benefit for people with Parkinson’s disease in controlled clinical trials."
Trial Design and Next Steps
The Phase I study was a multi-center, multi-site, open-label, non-randomized, non-controlled trial. Twelve subjects received surgical transplantation of either 0.9 million cells (Cohort A, 5 subjects) or 2.7 million cells (Cohort B, 7 subjects) of bemdaneprocel per putamen, bilaterally, along with a one-year immunosuppression regimen. Based on these results, planning is underway for a Phase II study that is expected to begin enrolling patients in H1 2024.
Parkinson's Disease Context
Parkinson’s disease affects more than 10 million people worldwide and is characterized by the progressive loss of dopaminergic neurons, leading to motor and non-motor symptoms. Current treatments offer symptomatic relief but do not halt disease progression, highlighting the urgent need for new therapeutic strategies. There is no cure and the effectiveness of current treatments decreases over time.
