Evaluation of Safety and Efficacy of Ruxolitinib in Patients with Pediatric Lymphoproliferative Disorders

Introduction. Pediatric lymphoproliferative disorders (PLPD) encompass a wide spectrum of immune dysregulation conditions with heterogeneous clinical presentation and lab abnormalities. The underlying mechanisms of PLPD are diverse, including dysregulated differentiation of immune cell populations, aberrant recruitment of lymphocyte populations, and/or retention and pathologic survival of lymphocytes. Many PLPD are associated with inborn or acquired genetic factors impacting immune function. Standardized measures to characterize clinical and biological factors in PLPD patients and responses to therapy are lacking. One common feature in PLPD patients is activating IFNg signaling. Ruxolitinib is a drug that blocks hyperactivated IFNg signaling through the JAK-STAT pathway. The goal of this study is to describe the clinical responses of PLPD patients to ruxolitinib.