A Pilot Study to Evaluate Safety and Tolerability, Pharmacokinetics, and Preliminary Efficacy of Quercetin in Patients With XIAP (X-linked Inhibitor of Apoptosis) Deficiency

XIAP deficiency is a rare genetic immune disorder. XIAP usually suppresses inflammation and XIAP deficiency leads to increased inflammation. Patients may develop several inflammatory problems including hemophagocytic lymphohistiocytosis (HLH), a life-threatening syndrome of overwhelming inflammation characterized by fever, low blood counts (cytopenias), an enlarged spleen, liver problems, seizures, and other manifestations. Patients may develop milder symptoms such recurrent fevers or problems with low blood counts. Inflammatory bowel disease (IBD), arthritis or inflammation of the eyes (uveitis) can also occur, among other more rare complications. XIAP deficiency is often life-threatening and patients with severe disease require treatment with allogeneic hematopoietic cell transplantation (HCT), which is the only available curative treatment. Unfortunately, allogeneic HCT is associated with a high risk of mortality and significant side effects. Therefore, it's important to find other treatment options that are safe without major side effects.

The purpose of the study is to evaluate safety and tolerability of oral quercetin in reducing inflammation in male patients with XIAP deficiency. Quercetin is a naturally occurring antioxidant that has many properties including the ability to decrease inflammation in other diseases.