This study is a phase II study, which means the investigational drug is continuously being tested for safety and effectiveness. The purpose of this study is to help Researchers find out if an investigational drug, called daxibotulinumtoxinA (DAXI) for injection, is safe and useful to treat ULS in adults after stroke or major brain injury and if the effects last longer than the placebo. An investigational drug is one that is not approved by the United States (US) Food and Drug Administration (FDA) for use by the general public.
In this research study, the investigational drug will be tested in study subjects with ULS and will be compared to placebo. Placebo is a substance that looks like the investigational drug but has no active drug in it.
DAXI for injection is composed of purified botulinum toxin type A, and it is formulated with the novel stabilizing peptide RTP004, and it is injected. The placebo is identical to the investigational drug, except that it does not contain the botulinum toxin type A or any other active ingredient.