What’s New in Parkinson’s Research: Disease-Modifying Trials Are Gaining Ground

Dr. Tanya Simuni, a leading neurologist and clinical trial expert, recently shared her take on how Parkinson’s clinical research is evolving — and why she believes we might be approaching a turning point. In a plenary session at 2025 International Congress of Parkinson’s Disease and Movement Disorders (MDS), held October 5-9, in Honolulu, Hawaii., she highlighted three key areas that stand out in the current wave of trials. First, she pointed out that therapies targeting alpha-synuclein — the protein that clumps in the brains of people with Parkinson’s — are progressing faster than before. One example she mentioned is a monoclonal antibody that has moved into phase-3 testing. While earlier trials missed their main goals, secondary signs of benefit were strong enough for the company to press on. This reflects a growing confidence in targeting fundamental biology, rather than just treating symptoms. Second, she emphasised the rise of GLP-1 based drugs — and even newer dual incretin agents — as potential disease-modifying therapies. These medications, originally used to treat diabetes, are now being repurposed to influence not just metabolic pathways but also brain health. Their popularity in the research world reflects their promise to affect disease progression in a more holistic way. Third, Dr. Simuni discussed genetically targeted therapies. These are drugs designed for people with specific genetic changes, offering a personalised treatment angle. While none of the latest genetic therapies have completed their final trials yet, the pipeline is becoming more sophisticated, and researchers are looking at how best to match people to the right drug based on their biology. One of the most encouraging parts of her discussion was her belief that the field has sharpened its tools. Unlike before, scientists can now more precisely pick who should join trials based on their genetic profile or disease subtype. We also now have better ways to verify whether a drug is hitting its target inside the brain. She described a kind of “golden triangle” for trial success: the right person, the right drug and the right biological target. If researchers can hit that mark, meaningful progress is more likely. That said, Dr. Simuni was realistic about the challenges. Even with these advances, it's not yet simple to prove in real time that a treatment is slowing the disease. Measuring progress in people is still hard, and tracking how drugs engage with specific mechanisms remains a technical hurdle. But she is clear that we are closer than ever to a meaningful shift — from managing Parkinson’s symptoms to actually changing the course of the disease. For people watching this from the sidelines — those living with Parkinson’s or supporting someone who is — the message is hopeful. These trials may not deliver a cure in the short term. But they represent a smarter, more personalised attempt to tackle what causes the disease, not just its effects. Over time, this could lead to treatments that preserve function, slow decline and offer new options based on each person’s biology. Photo: Tanya Simuni, MD, FAAN (Credit: Northwestern University)