Disease-modifying Efficacy of Sitagliptin Therapy in Early-stage Parkinson's Disease

Summary

Parkinson's disease (PD) is a progressive neurodegenerative disorder pathologically characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of α-synuclein (α-syn) aggregates. To date, all approved treatments, including levodopa, are primarily limited to symptomatic relief, and no disease-modifying therapy (DMT) has been established to fundamentally slow or halt disease progression. Large-scale epidemiological cohort studies conducted in Taiwan, Sweden, the United Kingdom, and other countries have consistently reported that, among patients with diabetes, DPP-4 inhibitor users had an approximately 30%-40% lower risk of developing Parkinson's disease compared with non-users. This study aims to evaluate whether 72 weeks of treatment with sitagliptin (100 mg once daily), compared with placebo, delays the time to confirmed motor progression in patients with early-stage PD receiving stable levodopa monotherapy. Confirmed motor progression is defined as an increase of ≥5 points from baseline in the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part III score assessed in the OFF state.

Timeline

Start

2026-12-15

Primary completion

2029-03-01

Completion

2029-04-01

Drugs

Indications