Phase I/II Study of Pacritinib, A JAK2/IRAK1/CSF1R Inhibitor, in Refractory Chronic Graft-Versus-Host Disease (cGVHD) After Allogeneic Hematopoietic Stem Cell Transplantation (HSCT)

Background: Chronic graft-versus-host disease (cGVHD) is an immune system disorder that can occur in people who have had a stem cell transplant. cGVHD can affect multiple organs and increase risk of disability and death. New treatments are needed to treat cGVHD after stem cell transplant. Objective: To test a drug (pacritinib) in people with moderate or severe cGVHD that has not responded to previous treatment. Eligibility: People aged 18 years and older with moderate or severe cGVHD that has not responded to 2 or more lines of previous treatment. Design: Participants will be screened. They will have blood and urine tests. They will have tests of their heart and lung function. They may also have a CT scan. Some may have other specialized tests. Participants will take the study drug at home every day. Pacritinib is a capsule taken by mouth. The study doctor will determine the dosage and schedule. Participants will keep a medication diary. They will record the date and time of each drug dose and any missed doses. Participants will visit the clinic every 2 weeks for the first 4 months. Then they will visit the clinic once every 4 weeks. They will have blood and urine tests. During some visits, other screening tests will be repeated, and participants will fill out questionnaires about their quality of life. Photographs may be taken of skin rashes and joints affected by cGVHD. Participants will give saliva samples. Optional biopsies may be taken of the skin and mouth. Participants will take pacritinib for 6 to 12 months if no side effects develop. Follow-up visits will continue for up to 2 years. ...