People waiting for advances in Parkinson’s treatment often hold two hopes: “I want to move a little more comfortably today,” and “I hope there will be a way to stop the disease getting worse.”
This issue looks at new clinical results in those two directions. One study added a new drug to existing treatment to reduce periods when medication was not working well. The other tested treatment in a high-risk stage before Parkinson’s was diagnosed. We explain both the promise and the remaining uncertainties.
A once-daily drug reduced the time when medication was not working well
🔍 What the study found
Even while taking medication, some people become stiff or find walking and hand movements difficult again before their next dose. These periods, when medication does not adequately control symptoms, are called OFF timePeriods when medication does not adequately control symptoms and movement becomes harder. ON time refers to periods when medication helps movement.Learn more. Periods when medication helps a person move more comfortably are called ON time.
Investigational solengepras is being developed for people who still experience OFF time despite their existing medication. Cerevance announced results from a Phase 3 trialA stage of clinical testing that gathers more evidence on effectiveness and safety in larger groups. Positive results still require separate regulatory review.Learn more involving 341 participants. Phase 3 studies provide important evidence for an application for approval by testing effectiveness and safety in a relatively large group.
Participants continued their usual Parkinson’s medication and received either solengepras 75 mg, 150 mg, or a placeboA comparison treatment without the active ingredient of the investigational drug. Differences between groups help researchers evaluate the drug's additional effect.Learn more, which contained no active trial drug. Neither participants nor assessors knew which treatment each person received. Outcomes were compared over 12 weeks. At the start, participants averaged about 5 hours and 39 minutes of OFF time a day.
The key result came from the 150 mg group. Daily OFF time fell by about 94 minutes from baseline, while the placebo group improved by about 57 minutes. The additional reduction compared with placebo was therefore about 37 minutes a day on average.
That distinction matters. Saying the drug itself reduced OFF time by 94 minutes would leave out the change also seen with placebo. The between-group difference of about 37 minutes is the relevant measure of the additional effect. It is an average, not a promise that every participant improved by the same amount.
ON time without troublesome dyskinesiaUnwanted writhing or other involuntary movements. These need to be distinguished from tremor and from periods when medication is wearing off.Learn more also increased by about 36 minutes a day more than with placebo. These are movements that happen without the person’s intention. The study assessed not just how much time movement was possible, but whether that time was free of troublesome involuntary movement. Scores assessing difficulties in everyday activities also improved more than with placebo.
Solengepras is designed to inhibit GPR6A receptor protein involved in brain signalling. Solengepras inhibits GPR6 through a pathway different from directly stimulating dopamine receptors.Learn more, a protein involved in signalling in the brain. Its pathway differs from existing dopamineA chemical messenger involved in movement control. Parkinson's treatments may replace deficient dopamine or act on related signals.Learn more-based therapies, potentially offering another option. A different mechanism does not mean no side effects: headache, nausea, insomnia and dyskinesia were reported in the 150 mg group.
The company plans to discuss a future approval application with the US Food and Drug Administration. This is a Phase 3 results announcement, not an approval or confirmation of availability in South Korea. A 12-week symptom study also does not establish that the drug slows disease progression.
✅ For people with Parkinson’s
The encouraging point is that another option is being developed to reduce periods not adequately controlled by existing medication. Extending useful medication coverage is an important treatment goal for people whose movement becomes difficult repeatedly during the day.
This study added a drug rather than replacing existing medication. It is not a reason to reduce your current medication or change the interval between doses.
At your next appointment, explain how long after a dose stiffness returns and which times of day are most difficult. Apart from waiting for a new medicine, this can help your clinician consider whether anything in your current treatment needs adjustment.
🙋 For family and care partners
When someone says “the medication is not working,” try to distinguish difficulty moving when it wears off from excessive unwanted movement while it is working. Both can look uncomfortable, but they can represent different problems.
Alongside dose times, separately note when stiffness begins and when unwanted movements appear. This can support a useful question at an appointment: “Can we reduce difficult periods while also managing involuntary movements?”
Researchers explored treatment before Parkinson’s develops
🔍 What the study found
Parkinson’s research includes not only symptom-control medicines, but attempts to find out whether changes can be slowed before the disease becomes fully apparent.
This trial studied people with REM sleep behaviour disorderA sleep disorder in which normal muscle relaxation during dreaming is impaired, allowing dream-related movements or sounds. Diagnosis requires medical assessment.Learn more. During dreaming, their muscles do not relax sufficiently, so actions in dreams can become actual movements or sounds. When no other neurodegenerative diseaseConditions involving progressive loss of nerve-cell function or damage to nerve cells. Diagnoses and courses differ between conditions.Learn more has been diagnosed, this is called isolated REM sleep behaviour disorder.
This condition is associated with a higher future risk of Parkinson’s and some other neurodegenerative diseases, making it relevant to earlier-treatment research. However, not everyone who moves during dreams has this disorder, and not everyone with the disorder develops Parkinson’s.
Syntara conducted a Phase 2 trialClinical testing that gathers preliminary evidence of effectiveness while continuing to assess safety. Small exploratory findings require further confirmation.Learn more of investigational SNT-4728 in 41 people with isolated REM sleep behaviour disorder. Participants were assigned to the drug or placebo in an approximately 3:1 ratio. They received treatment for 12 weeks and were observed for another 12 weeks after treatment stopped.
The drug is designed to inhibit enzymes involved in brain inflammation. Researchers assessed brain imaging as well as movement, cognition, quality of life and other measures.
The newly released finding concerns movement scores assessed by clinicians. The MDS-UPDRS Part IIIA scale used to assess Parkinson's symptoms in several domains. Part III evaluates motor signs through a clinician's examination.Learn more assesses slowness, stiffness, tremor, walking and postural stability together.
After 12 weeks of treatment, scores in the drug group improved slightly while those in the placebo group worsened. A difference was also observed 12 weeks after treatment stopped, and at that point it was statistically significantUnder a specified analysis, an observed result is difficult to explain by chance alone assuming no difference between groups. This does not establish a large or useful clinical benefit.Learn more. In the analysis used, chance alone was an unlikely explanation for the observed difference.
A difference persisting after treatment stopped provides a reason for further study. But this does not establish prevention of Parkinson’s or slowing of disease progression. The trial did not demonstrate fewer people developing Parkinson’s or a longer time before diagnosis.
There are clear limitations. Only 41 people participated, and motor assessment was one of several outcomes. The announcement did not provide the numerical difference in motor scores, making it difficult to judge whether people would notice a meaningful change in daily life.
Smartphone-based movement measures showed a similar direction but no statistically significant between-group difference. Other assessments, including cognition and quality of life, did not show marked changes. Even when considered alongside previously reported brain-inflammation imaging, these findings need confirmation in larger, longer trials.
✅ For people with Parkinson’s
The significance is that research is expanding beyond treating symptoms that have already appeared, towards intervening earlier.
This trial cannot tell us whether people already diagnosed with Parkinson’s would experience the same effect, because it studied a different population. SNT-4728 is still an investigational drug, not an available standard treatment.
It was not a study of ordinary insomnia or sleep talking. Do not decide that your sleep symptoms make you eligible for this research, or take existing medicines or supplements on your own to prevent Parkinson’s.
🙋 For family and care partners
If discussing nighttime behaviour with a clinician, go beyond “sleeping badly” and describe what you actually observed: shouting during dreams, large limb movements, falling from bed or injuries. Specific observations can make the conversation more useful.
Do not read this news as a prediction that a family member will develop Parkinson’s. Nighttime behaviour can have different causes. The research explores a treatment possibility in a high-risk group; it does not predict an individual’s future.
What you can do now
The first study moves closer to reducing difficult periods today. The second explores whether treatment might begin earlier. Their stages of development and meanings are different.
The immediate step is not changing medication, but noting changes to discuss at appointments. Distinguish medication wearing off, unwanted movements and nighttime behaviour, and share your questions with your care team.
We can welcome new treatment possibilities while looking carefully at who was studied and what was actually established.
ParkinON has explained clinical results released by the developers in plain language. This is distinct from reviewing full peer-reviewed papers and does not replace medical diagnosis or treatment. Discuss treatment decisions with your clinician.