Study of Ruxolitinib for Acute and Chronic Graft Versus Host Disease

While hematopoietic stem cell transplant (HSCT) is an effective therapy, graft versus host disease (GVHD) is the most significant complication after HSCT. Both acute GVHD and chronic GVHD are leading causes of non-relapse morbidity and mortality. Patients with solid organ transplants may participate in this study as well because these patients occasionally develop acute GVHD, which is biologically similar to acute GVHD after an HSCT. Acute graft versus host disease usually occurs within the first 100 days of transplant and can involve the skin, gut, or liver. Chronic graft versus host disease usually occurs after the first 100 days of transplant and can involve skin, eyes, mouth, joints, liver, intestines commonly. These two diseases are different, but both happen due to the imbalance of the donor immune system in the host. The purpose of this research is to learn more about ruxolitinib as a treatment for both acute and chronic GVHD. Specifically, the investigators would like to learn more about the pharmacokinetics (PK - the process of absorption, distribution, metabolism, and elimination from the body - meaning how the drug moves through the body) and the pharmacodynamics (PD - the body's biological response to the drug) of ruxolitinib.