A Study to Evaluate Safety and Efficacy of KM-819 in Healthy Adults and Participants With Parkinson's Disease

The overall study will consist of three parts (Part 1a, Part 1b and Part 2).Part 1 of this study will evaluate the safety, tolerability and plasma PK of multipleascending doses (MAD) of KM‐819 in healthy older adults (Part 1a) and participants withParkinson's disease (Part 1b). ‐ Part 1a is a randomized, double‐blind, Multiple Ascending Dose (MAD) study inhealthy older adults that will include 3 cohorts. ‐ Part 1b is a randomized, double‐blind, MAD study in participants with Parkinson'sdisease that will include 3 cohorts.Part 2 of the study is a randomized, double‐blind, multiple dose study in participantswith Parkinson's disease that will include 2 cohorts. It is designed to test the safety,tolerability, plasma PK and pharmacodynamic effects of KM‐819 in participants withParkinson's disease. The study will also assess the degree to which those treated withKM‐819 will experience gains in overall daily function within the context of improvedParkinson's disease motor and non‐motor symptoms in comparison to placebo. Participantswill be randomized to receive KM‐819 or matching placebo at doses to be determined basedon the findings from Part 1 in a 2:1 ratio.