Study of VQ-101 to Slow Progression in Adults with GBA1‑Associated Parkinson’s Disease

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What is this study about?

The study focuses on individuals with Parkinson’s disease who carry a single‑copy change, called a GBA1 mutation, in a gene that can affect the disease’s course. Participants will receive either the investigational tablet known as VQ-101 or a matching placebo pill, both taken by mouth.

The purpose of the trial is to determine whether VQ-101 can slow the progression of this form of Parkinson’s disease compared with placebo. After enrollment, participants will be followed for a period of about one and a half years, during which they will attend regular clinic visits to have their safety checked, report any side effects, and complete simple questionnaires and short tests that evaluate movement, thinking and daily function. Disease changes will be measured using a standard rating tool called the Movement Disorder Society – Unified Parkinson’s Disease Rating Scale, which scores the severity of motor and non‑motor symptoms.

1 enrollment and consent

you agree to take part in the study after receiving a clear explanation of the purpose, procedures, and possible risks.

your written consent is recorded before any study activities begin.

2 screening assessments

a series of medical examinations are performed to confirm that you have Parkinson’s disease with a heterozygous GBA1 mutation.

tests may include blood work, brain imaging, and questionnaires that evaluate movement and cognition.

3 randomization

after successful screening, you are randomly assigned to receive either v q-101 or a placebo tablet.

the study is double‑blind, meaning neither you nor the study staff know which product you receive.

4 baseline visit

you undergo initial measurements that include a movement rating scale (the MDS‑UPDRS), vital signs, electrocardiogram (ECG), and laboratory tests.

these results serve as the reference point for all future comparisons.

5 start of study medication

you begin taking an oral tablet each day as directed by the study protocol.

the tablet may contain v q-101 or be a matching placebo; both look identical.

the exact dose is defined by the study and is taken once daily for the entire treatment period.

6 regular follow‑up visits

you return to the clinic at scheduled intervals, typically every 12 weeks, for up to week 78.

during each visit, the study team repeats the movement rating scale, checks vital signs, performs ECGs, and repeats laboratory tests.

you also complete cognitive tests and questionnaires that measure daily functioning and quality of life.

7 safety monitoring

throughout the study you are asked to report any new symptoms or side effects, known as treatment‑emergent adverse events.

the study team evaluates the frequency, severity, and seriousness of any reported events.

8 final assessment and end of treatment

at week 78, you complete a final set of assessments that include the movement rating scale, cognitive testing, laboratory evaluations, and ECG.

the study medication is stopped, and you receive a summary of the study results that pertain to your participation.

Who Can Join the Study?

Be able to sign a written document that shows you understand the study and agree to take part (informed consent).
Be between 35 and 80 years old, male or female.
Have a doctor’s diagnosis of Parkinson’s disease for less than 5 years, using the standard guidelines from the Movement Disorder Society (MDS).
Have a score of 2.5 or lower on the Modified Hoehn and Yahr scale at screening and at the start of the study (this scale measures how severe Parkinson’s symptoms are; a lower score means milder disease).
Be a known carrier of a single altered copy (heterozygous mutation) of the GBA1 gene, confirmed by a qualified laboratory.
If you take Parkinson’s medicines such as levodopa or other symptom‑relieving drugs, you must have started them at least 90 days before screening and keep the same dose for at least 30 days (at least 60 days if the medicine is rasagiline).
Be able to swallow medication taken by mouth (oral medication).
Be able to complete all parts of the study on your own, as judged by the study doctor.
Agree to follow strict birth‑control rules during the study: men with female partners who could become pregnant must use condoms (or another highly effective method) during treatment and for at least 28 days after the last dose; men must not donate sperm during this time, and women must use a method that prevents pregnancy with a failure rate of less than 1 % per year. Methods such as periodic abstinence are not allowed.

Who Cannot Join the Study?

Having a type of Parkinson’s disease that is not the usual form, such as progressive supranuclear palsy, cortico‑basal syndrome, or multiple system atrophy, or Parkinsonism caused by medicines, toxins, or strokes.
Having other serious brain or nervous system diseases (e.g., Huntington’s disease, Alzheimer’s disease, stroke, frontotemporal dementia, normal pressure hydrocephalus).
Having unstable heart problems, such as a heart attack in the past year, unstable chest pain, heart failure, irregular heart rhythms, very slow (100 beats per minute) resting heart rate.
Having uncontrolled high blood pressure.
Having liver test results (bilirubin, ALT, AST) more than twice the normal limit.
Having kidney test results (creatinine) more than 1.5 times the normal limit.
Planning or having had major surgery within the past 60 days that could affect the study.
Having any other significant abnormal lab results that the doctor thinks are important.
Regularly experiencing motor complications from L‑dopa (the main Parkinson’s medicine) or showing signs of L‑dopa dysregulation syndrome.
Having psychosis (hallucinations or delusions).
Having freezing of gait and severe drop in blood pressure when standing up (orthostatic hypotension).
Carrying a known LRRK2 genetic risk variant or having two copies (homozygous) or mixed copies (compound heterozygous) of GBA1 mutations.
Having Gaucher disease (GD), which shows up as an enlarged liver or spleen, low blood cell counts, or bone problems.
Scoring less than 22 on the Montreal Cognitive Assessment (MoCA), a test of thinking and memory abilities.
Taking medicines for memory problems (such as cholinesterase inhibitors or memantine) within 30 days (or five drug half‑lives) before randomization.
Using ambroxol at doses higher than 120 mg per day (lower doses are allowed after a two‑week washout).
Having had any brain surgery for Parkinson’s disease, such as deep brain stimulation, pallidotomy, thalamotomy, or cell transplant.
Currently participating in, or having recently taken part in, another experimental drug study (within five drug half‑lives or two weeks after the last dose).
Previously taking part in an experimental cell or gene therapy study.
Having a history of substance use disorder (including alcohol) in the past year, a positive drug test, or unwillingness to avoid these substances during clinic visits (marijuana and cannabinoids are allowed if not used for at least 24 hours before visits).
Having a significant risk of suicide, as measured by the Columbia‑Suicide Severity Rating Scale (C‑SSRS), or having attempted suicide in the past year.
Having conditions that make a lumbar puncture (spinal tap) unsafe, such as bleeding problems, use of blood‑thinning medicines (except low‑dose aspirin), low platelet count, or other clotting issues.
Other criteria listed as “CCI” (unspecified clinical conditions) that the investigator deems exclusionary.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name	City	Country	Status
Oncopole Claudius Regaud	Toulouse	France

Other Sites

Site Name	City	Country
Suyckobso Rkrltju Uphdczsakl Mwmdmci Cnirzn	Nijmegen	The Netherlands
Jgkgttrkrslmjklvfvjzlnrnao Gssoyzd	Giessen	Germany
Hbhozirg Vhjg dlnubcyi	Barcelona	Spain

Trial status

Country	Status	Recruitment Start
France	Not yet recruiting	13.11.2026
Germany	Not yet recruiting	13.11.2026
Spain	Not yet recruiting	13.11.2026
The Netherlands	Not yet recruiting	13.11.2026

Trial locations

VQ-101 is an experimental oral tablet being studied to see if it can slow the progression of Parkinson’s disease in people who have a specific genetic change called a heterozygous GBA1 mutation. In the trial, participants take the tablet while researchers watch for any changes in their Parkinson’s symptoms, using a standard rating scale, and also monitor for any side effects to evaluate safety.

GBA1-associated Parkinson’s disease – This is a form of Parkinson’s disease that occurs in people who carry mutations in the GBA1 gene. It begins with typical motor signs such as tremor, stiffness, and slow movements, and may also include non‑motor features like sleep changes and mood swings. Over time the motor symptoms usually become more pronounced, and difficulties with balance and walking can increase. Cognitive abilities may gradually decline as the disease advances.

Trial ID:

2026-525848-15-00

Protocol code:

VQ101-201

Trial Phase:

Therapeutic exploratory (Phase II)

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Study of VQ-101 to Slow Progression in Adults with GBA1‑Associated Parkinson’s Disease

What is this study about?

Who Can Join the Study?

Who Cannot Join the Study?