Eltrombopag for Fanconi Anemia

Background: Fanconi anemia is a genetic disease. Some people with it have reduced blood cell counts. This means their bone marrow no longer works properly. These people may need blood transfusions for anemia (low red blood cells) or low platelet counts or bleeding. Researchers want to see if a new drug will help people with this disease. Objective: To find out if a new drug, eltrombopag, is effective in people with Fanconi anemia. To know how long the drug needs to be given to improve blood counts. Eligibility: People at least 6 years old with Fanconi anemia with reduced blood cell counts. Design: Participants will be screened with blood and urine tests. They will repeat this before starting to take the study drug. Participants will take eltrombopag pills by mouth once a day for 24 weeks. They will be monitored closely for side effects. Participants will have blood tests every 4 weeks while on eltrombopag. Participants will visit NIH 3 months and 6 months after starting eltrombopag. At these visits, participants will: Answer questions about their medical history, how they are feeling, and their quality of life Have a physical exam Have blood and urine tests Have a bone marrow sample taken by needle from the hip. The area will be numbed. If participants blood cell counts improve, they might join the extended access part of the study. They may continue eltrombopag for up to 3 years, with dose adjustment, taper, interruption, discontinuation, or re-initiation according to protocol criteria. After 24 weeks of treatment, if there is no improvement in blood cell counts, participants will stop taking eltrombopag. They will return for an optional follow-up visit that repeats the study visits.