The purpose of this study is to test the safety of triptorelin when used for the protection of the ovaries (pair of female reproductive organs) during cyclophosphamide therapy for systemic lupus erythematosus (SLE; lupus) and to see what effects (good or bad) it has on patients. The study will be done with female patients who have been diagnosed with systemic lupus erythematosus, are younger than 21 years of age, and require intravenous cyclophosphamide to control the disease. Each patient will be in the study for approximately 23 months, until 4 months after the intravenous cyclophosphamide treatment has been completed.