A Pilot Study of Ruxolitinib in Secondary Hemophagocytic Syndrome

Inclusion Criteria: * Patients, or their legally authorized representative, must voluntarily provide written IRB-approved informed consent. * Males and females, 18 years of age or older at the time of enrollment. * Patients must meet the diagnostic criteria for HPS (at least 5 of the following): fever, splenomegaly, cytopenia involving ≥2 cell lines (Hemoglobin \<9 g/dL; platelets \<100,000/μL; absolute neutrophil count \<1000/μL), hypertriglyceridemia or hypofibrinogenemia, tissue demonstration of hemophagocytosis, low or absent NK (Natural Killer) cell activity, serum ferritin ≥3000 ug/L, soluble IL-2 receptor (CD25) \>2400 U/mL. * In the investigator's opinion, the patient has the ability to participate fully in the study, and comply with all its requirements. Exclusion Criteria: * CNS (Central Nervous System) involvement * Malabsorption * Known secondary HPS (Hemophagocytic Syndrome) that is otherwise treatable (e.g. non-Hodgkin's lymphoma). * Pregnant or lactating female: all females of child-bearing potential must have a negative serum pregnancy test within 7 days of treatment; lactating females must discontinue breast feeding. * Estimated creatinine clearance \<15mL/min * Has received any prior systemic therapy, excluding corticosteroids, within 7 days (or 5 half-lives) of treatment. * No active malignancy at the time of enrollment, except nonmelanoma skin cancers or carcinoma in situ. Patients with a prior history of malignancy are eligible if their malignancy has …