BlueRock clears key hurdle in Parkinson's stem cell trial

stem cells

It's a case of so far, so good for BlueRock Therapeutics' first clinical trial of Parkinson's disease therapy bemdaneprocel, with no major safety issues reported after a year in patients who received the transplanted cells.

The Bayer subsidiary presented results from the ongoing phase 1 study at the International Congress of Parkinson's Disease and Movement Disorders (MDS) in Copenhagen, which showed no serious adverse events in 12 patients treated with low and high doses of bemdaneprocel (BRT-DA01), as well as preliminary evidence from PET imaging that the transplanted cells were surviving and growing in the brain.

Bemdaneprocel is administered by surgical transplantation into a part of the brain known as the putamen, in the hope of grafting dopamine-producing cells that can bolster the depleted levels of the neurotransmitter seen in Parkinson's.

Patients in the study also took immune-suppressing drugs to prevent rejection of the transplant for a year and will be followed for two years to check safety and see if the therapy has an impact on symptoms.

Two patients had serious adverse reactions in the trial, one a case of COVID-19 and one seizure that was thought to result from the surgery to implant the cells and was resolved without further complications.

While the data is still very early, the company said patients showed signs of clinical improvement, measured using the MDS-Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS Part III) and patients' own symptom diary records.

There was a greater effect in the higher dose group, pointing to a dose-response relationship, with a 13-point reduction from baseline in MDS-UPDRS Part III scores for the higher dose and a 7.6-point decline in the low-dose group.

With the initial readouts looking positive, BlueRock has said it plans to move ahead with a phase 2 trial that will examine the efficacy of bemdaneprocel more closely, with recruitment of patients due to start in the first half of next year.

The results were described as "extremely encouraging" by Claire Henchcliffe of the University of California, Irvine, one of the principal investigators in the trial.

"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," she said.

"The hope now is that these trends continue and translate into meaningful benefit for people with Parkinson's disease in controlled clinical trials."

The results put BlueRock among the leaders in the quest to develop stem cell-based therapies for Parkinson's. Other groups operating in this area include International Stem Cell Corp, which completed a phase 1 trial of its ISC-hpNSC candidate in 2021, and a team at Lund University in Sweden which got a green light to start a phase 1/2 study of their candidate last year.

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