Sirolimus for Focal Segmental Glomerulosclerosis

This study will determine the safety and effectiveness of sirolimus (Rapamune® (Registered Trademark)) in treating focal segmental glomerulosclerosis (FSGS), a disease involving kidney scarring and increased protein in the urine. About one-half of patients with FSGS go on to develop end-stage kidney disease within 6 years, requiring dialysis or kidney transplant. Therapies to reduce urine protein are likely to stop the progression of renal scarring and reduce the chance of developing kidney failure. However, current treatments for FSGS, such as prednisone, cyclophosphamide, and cyclosporine, are not effective in many patients and can cause serious side effects. This study will see if sirolimus, a drug with both anti-scarring and immune suppressing properties, can lower the amount of protein in the urine and slow or stop the kidney disease. Patients 13 years of age and older with FSGS who have had at least one standard treatment for FSGS may be eligible for this 24-month study. Pregnant and nursing women may not participate. Candidates will be screened with a medical history and physical examination, review of medical records and kidney biopsy, 24-hour urine collection, and blood tests. Participants will take sirolimus tablets once a day for 1 year. Three 24-hour urine collections will be done before starting treatment. Blood will be drawn to measure drug levels every week for the first month after starting treatment, then every other week for 1 month, and then every 2 months until treatment stops. Patients who do not have a complete response to the drug at low levels will have their dose increased. Patients will be seen at the NIH clinic in Bethesda, Md., for the screening visit and then at 1, 4, 8, 12, and 15 months for blood and urine tests. Additional urine collections and blood tests will be done periodically throughout the 24-month study period by the patient's local physician. Patients whose urine protein decreases on therapy will be asked to wait 3 months