‘Overwhelming’ patient interest
Participants in the study are screened for variants in seven genes known to be involved in Parkinson’s disease risk: GBA, LRRK2, PRKN, PINK1, SNCA, PARK7, and VPS35.
In less than 3 years, the study has already produced what is thought to be the largest genetic data bank of sequenced sets of Parkinson’s disease-risk genes made accessible to patients. Since the end of 2020, the first year of patient enrollment, the number of participants has increased from 676 to 10,515 and the number of participating clinical sites rose from 12 to 101.
The foundation has spent nearly $20 million on the project so far and plans to spend another $10 million to reach a goal of 15,000 patients. The study, which is funded by private donors, is so successful that the foundation has had to scale back enrollment.
“When we were at a peak, we had over 700 participants enrolling each month,” Dr. Beck said. Beginning in April, the program capped new sign-ups to 200 patients per month and created a waiting list for future enrollment. The waiting list is hundreds of patients long.
“The participants’ response to enroll in PD GENEration demonstrates there is an overwhelming interest by people with Parkinson’s disease to learn more about their genetic risk factors,” Dr. Alcalay said.
A research driver
Nearly 60% of participants enrolled so far are male and close to 80% are White. The average age is 69 years and 44% were diagnosed in the past 5 years. Close to 75% had never participated in a clinical trial.
Nearly 13% have tested positive for mutations on at least one of the seven target genes. Previous studies had suggested genetics were involved in only about 10% of cases.
The majority of those with positive results had early-onset Parkinson’s disease, high-risk ancestry, or a first-degree relative with the disease. However, 9% of people who tested positive weren’t in any of those categories.
Genetic information collected by the project is shared with the Global Parkinson’s Genetics Program (GP2), a resource program of the Aligning Science Across Parkinson’s initiative that is focused on the disease’s genetic architecture. Researchers around the world have access to GP2 data to study known gene variants and identify new ones.
PD GENEration participants can choose to be notified if they are carriers of gene variants discovered in the future.
“All DNA samples shared by participants are undergoing research-grade testing,” Dr. Beck said. “Not only do we want to be able to inform people with Parkinson’s disease about their genetic status, but we also want to be able to use this precious resource to further drive research into the genetics of Parkinson’s disease.”
Early success
Patient recruitment has long been one of the biggest challenges to any clinical trial’s success. Research suggests that 90% of all clinical trials fail to reach recruitment milestones in their allotted time frame and two-thirds of multicenter trials fold because too few patients sign up. Data from the Parkinson’s Foundation show that only about 1% of all patients with Parkinson’s disease participate in clinical trials.
Increasing those numbers is the primary goal of PD GENEration, Dr. Beck said. And there’s evidence it’s already paying off.
Earlier this year, one of the program’s participating clinical sites, Intermountain Health, in Salt Lake City, Utah, joined a phase 2 clinical trial of an experimental drug that targets a mutation on the GBA1 gene.
“One of the reasons we were able to participate was when we got the call about joining, we were able to say that we had patients with that specific gene mutation, and we could only say that because the patients had been genotyped through PD GENEration,” said Kathleen E. McKee, MD, director of movement disorders, associate medical director of neurosciences research, and PD GENEration principal investigator at Intermountain Health.
Since 2021, Dr. McKee has enrolled hundreds of patients in the foundation’s gene study and hopes to enroll even more. Few patients turn down the opportunity to participate, she added. Knowing their genotype has proven empowering for her patients, most of whom could not afford genetic testing on their own.
“Previously I would tell patients this is not going to change your immediate management,” Dr. McKee said. “Now I tell my patients that these trials are out there, it may actually change how I treat you and what I recommend.”
A version of this article appeared on Medscape.com.