Chronic Graft vs. Host Disease

Chronic graft-versus-host disease (cGVHD) is a condition that can develop after a stem cell transplant. It occurs when donor immune cells attack the body's tissues. In many people, cGVHD affects the skin, causing inflammation, thickening, and scarring that can limit movement and reduce quality of life. Axatilimab is a medicine approved by the U.S. Food and Drug Administration (FDA) to treat adults with cGVHD after at least two previous treatments have not worked well enough. Although axatilimab can improve cGVHD, researchers do not fully understand how it changes immune cells in the skin. The purpose of this study is to learn how axatilimab affects immune cells in the skin and blood of people with cGVHD. Researchers will study skin and blood samples collected before and after participants start axatilimab. The goal is to better understand how the medicine reduces inflammation and scarring and to identify biological changes that occur during treatment. This is an observational research study. The study does not decide whether participants receive axatilimab, when treatment starts, or what dose they receive. All treatment decisions are made by the participant's treating physician as part of routine medical care. About 15 adults with cGVHD involving the skin will participate. Ten participants who are starting axatilimab as part of their usual care will have three study visits: before treatment begins, about 2 weeks after starting treatment, and about 12 weeks after starting treatment. At each visit, participants will provide a small skin biopsy and a blood sample. Five participants with cGVHD who are not receiving axatilimab will serve as a comparison group and will complete one study visit with one skin biopsy and one blood sample. Researchers will also review participants' medical records and collect information about their skin disease over time. Information from this study may help researchers better understand how axatilimab works in people with cGVHD. The findings may also help improve future research and guide the development of treatments for cGVHD and other diseases that cause tissue scarring.

Background: * Chronic graft-versus-host disease (cGVHD) is a multi-organ alloimmune and autoimmune disorder that occurs following allogeneic hematopoietic stem cell transplantation (alloHSCT). It is characterized by immune dysregulation, immunodeficiency, impaired organ function, and decreased survival. * Each year about 8000 patients receive allogeneic hematopoietic stem cell transplant (alloHSCT) in North America and about 50% of patients who are transplanted develop cGVHD. * Chronic GVHD is also a disorder that simultaneously affects many organ systems in highly variable fashion and requires complex and coordinated medical management by multiple medical specialties. There is an urgent need for progress in understanding and effective treatments for cGVHD as it is one of the most serious complications of cancer therapy and hematopoietic stem cell transplantation. Objectives: * To establish a multidisciplinary clinic infrastructure for study of the pathogenesis and natural history of cGVHD. * To prospectively identify clinical and biological prognostic markers in patients with cGVHD * To develop clinically relevant cGVHD grading scales * To identify novel biological characteristics of cGVHD and to describe them in the context of clinical history and presentation * To identify potential clinical and biological markers of cGVHD activity * To improve understanding of the biology of cGVHD-associated graft-versus-tumor effects * To identify potential patients for cGVHD treatment protocols at the NCI and NIH Eligibility: -Patients age 1 and older referred by the primary transplant physician for the evaluation of chronic graft-versus-host disease independent of underlying diagnosis. Design: * Patient undergoes initial clinical and laboratory multispecialty work-up at the NCI cGVHD clinic. * Minimally invasive biopsies and rarely, deep tissue biopsy may be obtained to confirm the diagnosis and/or rule-out other pathologic process (in adults only). * Long tem data collection for evaluation of long-term outcomes will be conducted anually as feasible

The purpose of the study is to assess the efficacy and safety of ruxolitinib in Chinese adult and pediatric participants aged 12 years or older with corticosteroid-refractory chronic graft vs. host disease (SR-cGvHD).