It is hoped that TAK-071 will help people with Parkinson's disease to walk with better balance. The main aim of the study is to check if there is a difference in how participants walk after treatment with TAK-071. Another aim is to check for side effects.
At the first visit, the study doctor will check who can take part. Participants who can take part will be picked for 1 of 2 groups by chance.
Both groups will have 2 treatments but in a different order. The treatments are TAK-071 tablets or placebo. In this study, a placebo will look like the TAK-071 but will not have any medicine in it.
One group will take TAK-071 for 6 weeks, have at least a 3-week break, then take a placebo for 6 weeks. The other group will take a placebo for 6 weeks, have at least a 3-week break, then take TAK-071 for 6 weeks. The participants will not know the order of their 2 treatments, nor will their study doctors. This is to help make sure the results are more reliable.
The participants will visit the clinic at the beginning and end of each treatment for a check-up. 14 days after the 2nd treatment, clinic staff will telephone the participants for a final check-up.
Criteria:- Is an outpatient of any sex aged between 40 and <=65 years, inclusive, at the time of consent. At a later date, participants up to age 85 years may be enrolled.
- Has a diagnosis of PD according to Movement Disorders Society (MDS) clinical diagnostic criteria for PD. Participants with DLB (ie, dementia diagnosed before onset of motor symptoms or up to 1 year after onset of motor symptoms) are also eligible, consistent with MDS clinical diagnostic criteria for PD.
- Has Hoehn and Yahr stage >=2 and <4 at the screening visit.
- Has elevated risk for falls as indicated by at least 2 falls in the last 6 months before the screening visit based on the Fall History Assessment where in the opinion of the investigator the falls were a consequence of PD.
- Has evidence of cognitive impairment as indicated by a Montreal Cognitive Assessment (MoCA) score between 18 and 24, inclusive.
- Can walk without aid for 2 minutes while doing serial 3 subtraction (with site staff ensuring participant safety in case of falls). Participants who require aids for walking can be included as long as they can complete the walk test without aid.