CIRTEN-Simultaneous Pancreas-Kidney Transplant Recipients

Inclusion Criteria: * Adult, 18-70 years of age * Participant must be able to understand and provide consent * History of Diabetes Type 1 or Insulin-Dependent Diabetes Type 2 with Chronic Kidney Disease (CKD) * Recipient of a Simultaneous Pancreas Kidney (SPK) transplant, 3- 60 months prior to screening, per Principal Investigator's discretion. * Have a history of tremors following transplantation * Stable pancreas allograft function as evidenced by no requirement of exogenous insulin or oral anti-diabetic agents and stable pancreatic enzymes * Stable kidney allograft function * Currently taking Immediate-Release (IR) tacrolimus * Women of child-bearing potential (WOCP) must have a negative pregnancy test at the time of study entry Exclusion Criteria: * Currently maintained on an extended-release tacrolimus immunosuppressive regimen * Previous history of tremors prior to transplantation * Solitary pancreas transplant recipients * History of solid organ transplant other than a kidney or pancreas * Uncontrolled concomitant infection at the discretion of the investigator * Presence of Donor Specific Antibodies