Treatment of endometriosis with a delayed release preparation of the agonist D-Trp⁶-luteinizing hormone-releasing hormone: Long-term follow-up in a series of 50 patients

Fifty patients with proven endometriosis were treated for 6 to 9 months with a delayed release preparation of microcapsules of the luteinizing hormone-releasing hormone (LH-RH) agonist D-Trp⁶-LH-RH, injected intramuscularly at monthly intervals. After a transitory ovarian stimulation at the onset of treatment, serum estradiol was suppressed to menopausal levels (50 pg/mL). This state of hypogonadism was reversible after the discontinuation of treatment, and menses resumed within 4 months after the last injection. Pelvic pain was relieved during treatment in 87.5% of patients. After a follow-up period of up to 37 months, 24 patients are in clinical remission and 9 experienced recurrence of endometriosis 7 to 14 months after completing treatment. One patient failed to respond to therapy with the agonist and 7 patients were lost to follow-up. Among 16 previously infertile patients with no other factors contributing to infertility, 7 became pregnant; 2 of these pregnancies were the result of gamete intrafallopian transfers. An eighth patient without documented infertility also conceived spontaneously. Side effects due to hypoestrogenism were reported by nearly all patients. In conclusion, D-Trp⁶-LH-RH microcapsules are effective and easily-administered agents for the treatment of endometriosis.