A Study of Ibrutinib + Obinutuzumab in Patients With Relapsed or Refractory Chronic Lymphocytic Leukemia

This research study is a Phase I clinical trial, which tests the safety of an investigational intervention and also tries to define the best order of administration of these two drugs. "Investigational" means that the intervention is being studied. The FDA (the U.S. Food and Drug Administration) has approved ibrutinib and obinutuzumab individually for the treatment of patients with Chronic Lymphocytic Leukemia, your type of cancer. However, the FDA has not approved the combination of these two drugs as a treatment for any disease. Ibrutinib is a type of drug called a kinase inhibitor. It is believed to block a type of protein called a kinase that helps leukemia cells live and grow. By blocking this, it is possible that the study drug will kill cancer cells or stop them from growing. Obinutuzumab is a type of drug called a monoclonal antibody. It is believed to attach to a protein called CD20 on the outside of a Chronic Lymphocytic Leukemia cell. By attaching to the cell, the antibody can cause the Chronic Lymphocytic Leukemia cell to die. In this research study, the investigators are assessing the safety of various dosing regimens of ibrutinib and obinutuzumab. The investigators are trying to determine whether it is better to give one drug before the other or if they can be started at the same time.