The purpose of this clinical research study is to look at an investigational study drug called lenrispodun. The study will investigate if lenrispodun can help to increase the time of good control of movement symptoms, that is, to reduce periods of slowness and difficulty starting movement, and reduce periods of involuntary, uncontrollable muscle movements, such as twitching, tremors, and jerking (called dyskinesia) in people with Parkinson’s disease (PD). Lenrispodun will be used alongside a standard-of-care (usual care) treatment with an approved drug called levodopa. The study will look at a 30 mg/day dose of lenrispodun compared with a placebo (a placebo looks the same as lenrispodun but contains no active ingredients) to see: If lenrispodun works to reduce involuntary muscle movements and how safe lenrispodun is.