This clinical research study is evaluating an investigational treatment for people with cutaneous lupus erythematosus (CLE), a condition that causes inflammation and rashes on the skin. The purpose of the study is to learn whether the study treatment can help improve lupus-related skin symptoms and to better understand its safety. Participants will receive either the study treatment or a placebo (inactive treatment) in addition to their usual lupus care. All participants will be closely monitored by the study team throughout the study. Taking part is voluntary, and participants may leave the study at any time.