JAK1/2 Inhibitor Ruxolitinib for Relapsed/Refractory Immune Bone Marrow Failure

Background: Immune bone marrow failure is a condition that occurs when a person s immune system attacks the cells of the bone marrow. This can lead to diseases including different types of anemias and blood cancers. Some of these diseases can be deadly. Better treatments are needed. Objective: To test a drug (ruxolitinib) in people with different types of immune bone marrow failure. Eligibility: Adults aged 18 and older with an immune bone marrow failure. Design: Participants will be screened. They will have a physical exam. They will give samples of blood and saliva. They will have a bone marrow biopsy: A large needle will be inserted into a small cut to remove a sample of the soft tissue inside the bone. Some participants may have a skin biopsy: A small piece of skin will be removed. Some may have a computed tomography (CT) scan: They will lie on a table that slides into a donut-shaped machine that uses X-rays to make pictures of the inside of the body. Ruxolitinib is a tablet taken by mouth. Participants will take the drug twice a day for up to 6 months. Participants will have blood tests every week while they are taking the drug. These tests can be done by the participant s own physician and the results sent to the researchers. Participants will have clinic visits after taking the drug for 3 months and 6 months and then after 1, 2, and 3 years. The blood tests and bone marrow biopsy will be repeated. Participants who improve while taking the drugs may go on to an extension phase of the study.

NCT Number	NCT05998408
Lead Sponsor	National Heart, Lung, and Blood Institute (NHLBI)
Conditions	Severe Aplastic Anemia, Single Lineage Cytopenias, T-LGL, Hypoplastic MDS
Enrollment	13 participants
Start Date	2024-02-20
Primary Completion	2025-07-22 (estimated)
Study Completion	2032-06-03 (estimated)
Updated on ClinicalTrials.gov	2026-07-15