PMDC joins landmark trial for stem cell-based Parkinson’s disease therapy

By John Battiston 

The VCU Parkinson’s and Movement Disorders Center (PMDC) is participating in one of the most ambitious Parkinson’s disease studies ever conducted in the United States: the exPDite-2 clinical trial. 

exPDite-2 is a phase 3, double-blind, simulated surgery-controlled clinical trial evaluating an investigational cell therapy called bemdaneprocel. Developed by Massachusetts-based company BlueRock Therapeutics, bemdaneprocel is designed to replace dopamine-producing neurons that are lost in Parkinson’s disease, targeting an underlying cause of the condition rather than managing symptoms. In doing so, it may dramatically improve motor symptoms associated with Parkinson’s and replace the need for dopamine-boosting oral medications. 

“One of the largest areas of research right now in Parkinson's disease therapeutic development is cell-based therapy, specifically stem cell-based therapy,” says Leslie Cloud, M.D., director of the PMDC’s Parkinson’s disease program. As she explains, Parkinson’s disease progresses as dopamine-producing neurons die off, leading to worsening movement and balance problems over time. “Stem cell therapies like bemdaneprocel seek to take stem cells and turn them into dopamine-producing neurons in a lab.” 

What sets exPDite-2 apart is both its promise and its rigor. It is the only U.S. study that has made it all the way through phase 1 and phase 2 clinical trials with sufficient safety and efficacy data to begin phase 3 trials. If it passes phase 3 trials, bemdaneprocel can be submitted to the Food and Drug Administration for approval. “exPDite-2 is the pivotal study that's going to make it or break it for this therapy,” Cloud says, “and the early data look very promising.” 

Participants in the trial are randomly assigned to receive either a one-time surgical implantation of bemdaneprocel into the brain or a simulated (“sham”) surgery. Neither patients nor most of the research team know which procedure a participant has received, preserving the integrity of the results. 

This double-blind design is especially important in Parkinson’s research. “In Parkinson's disease specifically, the placebo effect is quite robust, so it's important in a Parkinson's disease therapeutic trial to have a placebo arm,” Cloud says. “Every patient who leaves the operating room leaves with the same external stitches, but they have no way of knowing if anything happened inside or not.” 

At trial locations including the PMDC, maintaining that blind requires careful coordination. Cloud says she and her team divide responsibilities between blinded and unblinded staff, “making sure that nobody knows what they’re not supposed to.” The PMDC enrolls participants locally and will follow them closely for years after surgery, monitoring their safety, symptoms and quality of life. 

For patients, the study is a high-risk, potentially high-reward opportunity that Cloud says “is not for the faint of heart — they’re consenting to having a foreign cell line infused in their brain.” Yet interest has far exceeded expectations, reflecting decades of unmet need and a widespread desire for a new kind of treatment. 

“Parkinson’s patients have been waiting for a long time for a real groundbreaking solution to be offered to them; it’s always just more pills that basically do the same thing,” Cloud says. “Because bemdaneprocel might be able to do more, people seem less focused on the risk than the potential reward. They want to help get it across the finish line to make it available for others.” 

Looking ahead, Cloud is excited at the prospect of giving individuals with Parkinson’s disease an unprecedented intervention. “To offer something that has the potential to change the progression of their symptoms from a downward-trending line to a stable or even upward-trending one — we’ve never had anything like that before,” she says. “We could keep them from ever having to go through what patients today live with.” 

Patients or care partners interested in learning more about participation in the exPDite-2 study can contact the PMDC research team for additional information and screening details.