Buspirone Treatment of Iatrogenic Dyskinesias in Advanced Parkinson’s Disease. Multicenter, International, Placebo-controlled, Randomised, Double-Blind Trial

The study is a phase 3 multicenter, randomized, placebo-controlled, double-blind trial looking at the efficacy of buspirone in reducing dyskinesia in PD participants. They aim to enrol 100 clinically diagnosed PD participants between 35 to 80 years of age. The dyskinesia is required to be moderately disabling and to be present more than 25% of the waking time. The participant should be able to identify dyskinesia, ON and OFF periods. They should be on stable antiparkinsonian medications and be considered optimally treated at the time of inclusion. Standard exclusionary criteria are applied. Participants with DBS can be included if the procedure was done 12 months before inclusion and they are on stable stimulation parameters for at least 4 weeks prior to the first visit. The study will randomly assign participants to two study arms. Arm 1 will receive buspirone orally in escalating doses. For the first two weeks, they will be on 10mg daily morning dose followed by 10mg twice a day for the next two weeks to finally build up to 10mg three times a day from week 5 to 12. Arm 2 will receive capsules of placebo and administered in escalating doses to match the arm 1. Assessments will be done every 2 weeks and at the end of the study.