Cohorts 2 through 5 will consist of 4 participants each who have burn scars with restrictive scar contractures. The purpose of these cohorts is to evaluate the ongoing safety of the investigational drug (ICX-RHY-013) in post burn scars with restrictive scar contractures. The investigational drug will be injected directly into these scar contractures. Each cohort is unique in that the dose and frequency of the investigational drug received will be different. We will evaluate the safety of the drug between each cohort by assessing all side effects that the participants may experience.