Ruxolitinib for Immune Effector Cell Associated Hemophagocytic Lymphohistiocytosis-like Syndrome (RISE)

This is a pilot study to gather information about safety and efficacy of using ruxolitinib (RUX) to treat Immune Effector Cell Associated Hemophagocytic Lymphohistiocytosis-like Syndrome (IEC-HS) occurring after CAR-T therapy. In addition, correlative studies will be done to 1) estimate the optimal duration of RUX therapy, 2) to identify immunological biomarkers associated with response (3) To evaluate the dynamics of CAR T expansion following RUX treatment. Oral RUX will be administered twice daily, with dosing determined by the participant's baseline platelet count. Treatment will continue for up to 8 weeks unless significant adverse events occur or the treating physician concludes that the therapy is no longer providing clinical benefit. The study expects to accrue 16 evaluable patients diagnosed with IEC-HS over 2 years.