Trial to Evaluate the Efficacy and Safety of KM-819 Treatment to Slow the Progression of Multiple System Atrophy (MSA)

This is a randomized, double-blind, placebo-controlled phase II trial. This trial will be performed in two part: Main study and Ancillary study.

Main Study: Following a 4-week screening period, subjects will be stratified by MSA subtype (MSA-P, -C \[MSA-Parkinsonian type, MSA-cerebellar ataxia\]) and randomly assigned in a 1:1 ratio either to KM-819 or Placebo groups.

During a treatment period of 36 weeks, subjects will receive pills of either KM-819 or Placebo for oral administration every day from baseline visit. Following this, there will be a safety follow-up period at Week 40.

Ancillary Study: This ancillary study will provide additional information on the continuing efficacy and safety of KM-819. Subjects in either treatment group in the main study who complete the study are eligible to participate in a follow-up, all-subjects-on-treatment (KM-819), open-label ancillary study.

All subjects in the ancillary study will receive KM-819 for additional 36 weeks regardless of their treatment allocation during the main study. During a treatment period of 36 weeks, subjects will receive pills of KM-819 for oral administration every day from visit at Weeks 40.