Evaluating the Safety, Tolerability and Efficacy of SYN120 in Parkinson’s Disease Dementia

Study Rationale:
Cognitive impairments — common in Parkinson’s disease — are associated with an imbalance in neurotransmitters (substances that allow nerve cells to communicate with one another) such as serotonin. Drugs that block certain types of serotonin receptors have been shown to improve cognition in studies, but no medications are currently FDA-approved with this mechanism of action. Biotie Therapies is developing SYN120 as an orally administered drug that blocks two serotonin receptors in the brain (5-HT₆ and 5HT_2a) to treat Alzheimer’s disease and Parkinson’s disease.

Hypothesis:
This study seeks to determine if SYN120 is safe and tolerable and can improve cognition in Parkinson’s disease patients with dementia.

Study Design:
This is a Phase IIa, multicenter, randomized, double-blind, placebo-controlled, two-arm, 16-week study in Parkinson’s disease dementia patients taking a cholinesterase inhibitor. This includes a screening period of up to six weeks, a 16‑week treatment period and a two-week safety follow-up period. Eligible volunteers will be randomized to receive placebo or SYN120. Participants will return for evaluation at the study site at weeks four, eight and 16.

Impact on Diagnosis/Treatment of Parkinson’s Disease:
An effective therapy for cognitive dysfunction and dementia in Parkinson’s disease would greatly improve quality of life for patients and their loved ones.

Next Steps for Development:
Assuming this pilot study is positive, the next step will be to conduct a six-month dose-finding study (Phase IIb) comparing three to four doses of SYN120 to placebo in order to identify the optimal dose(s). At least one six-month, Phase III study comparing the optimal SYN120 dose to placebo would then be needed in order to request approval from the U.S. Food and Drug Administration.

Trial Phase: IIa