Study of the Safety and Efficacy of Ruxolitinib Cream for Non-Sclerotic Chronic Cutaneous Graft-Versus-Host Disease

Inclusion Criteria: * Patients (≥ 12 years) * History of allogeneic hematopoietic stem cell transplantation * BSA of at least 2% of clinically or histologically confirmed non-sclerotic cutaneous chronic graft-versus-host disease (diagnosed and BSA calculated in accordance with the National Institutes of Health Chronic Graft-versus-Host Disease Consensus for Clinical Trials: I. The 2014 Diagnosis and Staging Working Group Report) * Patients age ≥ 18 years must provide written informed consent; or patients age ≥12 years and \<18 years must provide assent and have at least one guardian provide written informed consent to participate in the study. * Able to self-administer topical interventions or provide for another person to apply the topical interventions (while wearing nitrile gloves) * If on systemic therapy for GVHD, systemic therapy must be stable for past 4 weeks; however, any planned systemic corticosteroid taper during the study will be permitted.Changes in systemic therapy during the study period will be allowed for the management of non-skin GVHD. * Any concurrent topical therapies including topical corticosteroids, topical calcienurin inhibitors, moisturizers, phototherapy (narrowband UVB or UVA1); or excimer laser therapy must be discontinued on Study Day 0. Exclusion Criteria: * Known history of allergy to any ingredient of the study medication * Patients with deep sclerotic cutaneous graft-versus-host disease including deep sclerotic subtypes of chronic cutaneous GVHD * Use of concurrent topical therapy including topical corticosteroids, topical calcienurin inhibitors, moisturizers, phototherapy (narrowband UVB or UVA1); or excimer laser therapy after Study Day 0 up to and including Study Day 28. * Changes in systemic therapy during study period for the purpose of treating skin GVHD. * Special populations: * vulnerable populations e.g. decisionally impaired (cognitive, psychiatric), terminally ill, prisoners * patients who, in the opinion of the investigator have a condition that precludes their ability to provide an informed consent * Concurrent participation in another topical trial of a drug(s) or medical device, or the subject is in an exclusion period after a previous trial of drug(s) or medical device * Pregnancy or lactation * Patients with inadequate liver function (ALT above 4 × upper limit of normal \[ULN\] for the patient's age or direct bilirubin 4 × ULN for the patient's age and the laboratory abnormalities are considered to be due to underlying liver dysfunction) unless attributed to GVHD (if direct bilirubin is not in the medical record, it is acceptable to use total bilirubin x4 ULN). * Active uncontrolled infection requiring systemic therapy. Subjects with a controlled infection receiving definitive therapy for 48 hours prior to enrollment are eligible.