Study to Compare the Outcome of Receiving Continued Immunosuppression Versus Stopping Immunosuppression at 6 Months to Safely Prevent Human Leukocyte Antigen (HLA) Sensitization in Patients With Late Renal Graft Failure

The goal of this clinical trial is to compare the degree of HLA sensitization at 2 years in patients with late renal graft failure (\> 3 months) when receiving reduced immunosuppressant treatment versus stopping immunosuppression at 6 months. The main question this study aims to answer is: Does maintaining long-term immunosuppression in patients with a late renal graft failure (\> 3 months) safely reduce the risk of HLA sensitization? To answer this question, patients will be assigned to a control arm or investigational arm: * Patients assigned to the control arm will receive standard treatment, in which immunosuppressant treatment is withdrawn after 6 months. * Patients assigned to the investigatonal arm will continue immunosuppressant treatment at low doses for 2 years. Patients recruited in this clinical trial will be followed for up to 2 years. During this time, patients will visit the clinic every 3 months for checkups and tests.