Ibrutinib is an effective drug that can extend the lives of CLL patients but it is not curative as a single agent and may eventually select for more aggressive disease. Survival of CLL cells in the presence of Ibrutinib may be enabled by signals from the microenvironment where the leukemia cells originate. These signals are transmitted into the cells by Janus Kinases (JAKs) such as janus kinase 1 (JAK1) and janus kinase 2 (JAK2). According, JAK inhibitors may overcome the cytoprotective properties of the CLL microenvironment and help to improve outcomes with Ibrutinib.~The JAK2 inhibitor Ruxolitinib is licensed for use in myelofibrosis and polycythemia rubra vera and its toxicity and efficacy as a single agent in CLL has been studied in two previous clinical trials. As a single agent, Ruxolitinib was inferior to Ibrutinib. However, Ruxolitinib was shown to cooperate with Ibrutinib and increase killing of CLL cells in vitro. Based on these observations, it is hypothesized that Ruxolitinib will significantly improve the therapeutic efficacy of single-agent Ibrutinib.~This is a single center phase I/II trial to determine the efficacy and safety of ruxolitinib tablets in CLL patients being treated until progression with Ibrutinib and considered at risk to progress on the basis of persistent lymphocytosis and lymphadenopathy after 1 year of Ibrutinib or elevated beta-2-microglobulin (b2M) levels after 6 months of Ibrutinib. Ruxolitinib will be administered for 21 days of a 35-day cycle to be repeated 6 more times.
This study involves adding the kinase inhibitor Ruxolitinib to Ibrutinib to treat Chronic Lymphocytic Leukemia (CLL).