Cyclophosphamide (CYC) therapy for systemic lupus erythematosus (SLE), a disease predominantly affecting women of childbearing age, causes an unacceptably high incidence of irreversible premature ovarian failure (POF). This study was performed to evaluate the effectiveness of depot leuprolide acetate, a synthetic gonadotropin-releasing hormone analog (GnRH-a), for protection against POF during CYC therapy.

Young women with severe SLE treated in a standardized protocol of monthly intravenous bolus CYC were offered treatment with GnRH-a (depot leuprolide acetate; a 3.75-mg monthly injection during the standard CYC regimen). Patients treated with GnRH-a were compared with controls individually matched by age (+/-5 years) and by cumulative CYC dose (+/-5 gm). Reproductive status was determined after a minimum followup of 3 years after CYC therapy. The primary outcome was time to POF. Paired summary statistical analyses, Kaplan-Meier survival estimates, and Cox regression analyses were performed to assess differences in outcome between groups.

POF developed in 1 of 20 women treated with GnRH-a (5%) compared with 6 of 20 controls (30%) matched by age and cumulative CYC dose (matched odds ratio 0.09, P < 0.05). Kaplan-Meier estimates demonstrated improved cumulative ovarian protection over time in the GnRH-a-treated group (P = 0.04).

Treatment with GnRH-a during CYC therapy was associated with a significant reduction of POF in young women with severe SLE.