Study to Evaluate the Efficacy of Ruxolitinib 1.5% Cream in Adult Subjects with Discoid Lupus Erythematosus

Inclusion Criteria: * Male or female subject 18 years of age or older at the time of consent. * Confirmed DLE diagnosis. * Subject has moderate to severe DLE, as defined by an overall CLA IGA score of 3 (moderate) or 4 (severe) at screening and Day 1. * Female subject of childbearing potential must have a negative urine pregnancy test at screening and negative urine pregnancy test at Day 1. * Subject has no known history of latent or active tuberculosis (TB) infection. * Subject is willing to participate and is capable of giving informed consent. Note: Consent must be obtained prior to any study-related procedures. * Subjects must be willing to comply with all study procedures and must be available for the duration of the study. Exclusion Criteria: * Female subject who is breastfeeding, pregnant, or who is planning to become pregnant during the study. * Subject has a history of skin disease or presence of skin condition that would interfere with the study assessments. * Subject has unstable or fluctuating use of nicotine-containing products within 4 weeks prior to screening. * Subject is known to have immune deficiency or is immunocompromised. * Subject is ≥ 50 years old AND has a history of heart attack, other clinically significant heart problems, stroke, or blood clots. * Subject has a known history of chronic infectious disease (e.g., hepatitis B, hepatitis C, or human immunodeficiency virus \[HIV\]). * Subject is known to have hepatitis B or hepatitis C viral infection. * Subject has used any topical medicated treatment that could affect DLE within 2 weeks prior to Day 1, including, but not limited to, topical corticosteroids, retinoids, calcineurin inhibitors, antimicrobials, and medical devices. * Subject has received any marketed or investigational biological agent within 12 weeks or 5 half lives (whichever is longer) prior to Day 1, including but not limited to ustekinumab and rituximab. * Subject is currently receiving a nonbiological investigational product or device or has received one within 4 weeks prior to Day 1. * Subject has a known or suspected allergy to ruxolitinib. * Subject has used ruxolitinib cream (OpzeluraTM). * Subject has used JAK inhibitors for conditions other than DLE or other forms of lupus within 4 weeks prior to Day 1. * Subject has a known history of clinically significant drug or alcohol abuse in the last year prior to Day 1.