Glovadalen Shows Potential to Ease Parkinson’s Motor Fluctuations

A new drug called glovadalen, developed by UCB Biopharma in Belgium, has shown encouraging results in reducing motor fluctuations in people with advanced Parkinson’s disease. These are the times when medication stops working properly and symptoms like stiffness or slowness return, often several times a day. The results come from the Phase 2 ATLANTIS trial, which involved more than 200 participants across several countries. Everyone in the study had been living with Parkinson’s for at least five years and was already taking levodopa, the standard treatment. Over ten weeks, patients took either glovadalen or a placebo alongside their usual medication. Those taking glovadalen spent less time in the “off” state each day, meaning their medication worked more consistently. The reduction averaged nearly an hour per day, which researchers said was statistically significant. Importantly, patients themselves reported feeling better, with twice as many people on the active drug saying their symptoms had improved compared to those on placebo. Glovadalen works differently from current dopamine-based drugs. It is what’s known as a D1 receptor positive allosteric modulator (D1 PAM). In plain terms, instead of flooding the brain with dopamine or directly stimulating its receptors, it subtly enhances how the brain’s own dopamine works when it is naturally released. This fine-tuning approach aims to improve motor control without triggering common dopamine-related side effects such as hallucinations, confusion, or extreme sleepiness. According to Dr Milton Biagioni, senior medical director at UCB and the trial’s lead investigator, one of the surprises was the low dropout rate of only 7% and the absence of serious side effects. Mild issues like headache or slight worsening of involuntary movements (dyskinesias) were reported, but these occurred at similar rates in the placebo group. The trial tested two doses of glovadalen, and both showed benefit. However, researchers emphasised this was an early proof-of-concept study, meaning the goal was to confirm that the drug’s mechanism works safely in humans rather than to establish the best dose. Future studies will likely explore higher doses to see whether the benefits can be strengthened without compromising safety. Glovadalen is part of a new wave of drugs designed to target dopamine more precisely. Unlike older dopamine agonists, which can overstimulate the brain and cause long-term side effects, D1 PAMs act only when dopamine is present and needed. This may help avoid problems like excessive movement or mood changes. Another drug with a similar focus, tavapadon by AbbVie, recently completed late-stage testing and has been submitted for approval to the US Food and Drug Administration. Both compounds belong to what scientists expect could become a new class of Parkinson’s treatments targeting the D1 and D5 dopamine receptors. Dr Julie Pilitsis, a neurosurgeon at the University of Arizona who was not involved in the study, described the results as “promising.” She noted that even a modest reduction in “off” time made a noticeable difference to how patients felt. She also praised the researchers for asking participants directly about their experiences rather than relying solely on clinical scores. Pilitsis added that longer studies will be needed to confirm whether glovadalen remains effective over time and whether subtle side effects, like dyskinesias, might appear later. For now, the findings point towards a potential new tool for managing the ups and downs of Parkinson’s symptoms. While it won’t replace current treatments yet, glovadalen’s unique mechanism may one day help people achieve smoother, more stable control of their movement throughout the day.