Treatment of endometriosis with a potent agonist of gonadotropin-releasing hormone (nafarelin)*

FERTIUTY AND STERILITY Copyright" 1985 The American Fertility Society

Vol. 44, No.5, November 1985 Printed in U.8A.

Treatment of endometriosis with a potent agonist of gonadotropin-releasing hormone (nafarelin)*

Eldon Schriock, M.D.H Scott E. Monroe, M.D.+ Milan Henzl, M.D.§ Robert B. Jaffe, M.D.+II University of California, San Francisco, and Syntex Research, Palo Alto, California

Administration of superactive agonistic analogs of gonadotropin-releasing hormone (GnRH) has been shown to induce a paradoxic and reversible suppression of gonadotropins, resulting in suppressed gonadal steroid concentrations. Because there currently is no uniformly successful and acceptable medical therapy for endometriosis, we examined the effects of 6 months of nasal administration (500 jLg every 12 hours) of the agonistic analog of GnRH, nafarelin, on clinical signs and symptoms and hormonal profiles in eight women with endometriosis. All patients had prompt and near-complete relief from their painful symptoms of endometriosis. Laparoscopy or laparotomy, performed both before and after treatment in seven of the women, revealed complete resolution of active endometriotic lesions in five patients and only a single, small cul-de-sac implant in a sixth woman. A large ovarian endometrioma decreased slightly in response to treatment in the seventh woman. Serum luteinizing hormone and follicle-stimulating hormone concentrations, after a transitory stimulation at the onset of treatment, declined and were suppressed (P < 0.001) during the remainder of treatment. Serum estradiol concentrations fell to approximately menopausal levels « 30 pg/mlJ after 1 to 4 weeks. Reversibility of drug effect was prompt, with ovulatory menses returning 47 ± 8 days (± standard deviation) after treatment. Thus, nasal administration of agonistic analogs of GnRH may represent a new treatment modality for endometriosis. Fertil Steril44:583, 1985

Received June 3, 1985; revised and accepted July 30, 1985. *Supported in part by contract 1-HD-0-2811 of the National Institute of Child Health and Human Development, Bethesda, Maryland. tPostdoctoral Fellow. Present address: Department of Obstetrics and Gynecology, University of Tennessee College of Medicine, Memphis, Tennessee. :j:Reproductive Endocrinology Center, Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco. §Syntex Research, Section on Reproductive Medicine. IlReprint requests: Robert B. Jaffe, M.D., Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, San Francisco, California 94143. Vol. 44, No.5, November 1985

Endometriosis is a common disease often associated with dysmenorrhea, dyspareunia, pelvic pain, and infertility. There is no uniformly successful treatment for endometriosis when the potential for future fertility must be maintained. Present therapeutic options include conservative surgery or ovarian suppression with progestogens (with or without estrogen) or danazol. Although significant improvements in pregnancy rates and regression of symptoms have been reported with the use of danazol, not all women respond favorably to the medication and some have troublesome side effects. 1, 2 Schriock et aI. GnRH analog therapy for endometriosis

583

Administration of potent long-acting agonistic analogs of gonadotropin-releasing hormone (GnRH) suppress gonadotrope responsiveness to endogenous GnRH, resulting in decreased secretion of luteinizing hormone (LH) and folliclestimulating hormone (FSH) and, secondarily, reduced ovarian steroid production. Long-term administration of GnRHagonists can inhibit ovulation effectively and at higher doses can reduce serum estrogen concentrations to approximately menopausal levels. 3 - 5 This paradoxical action of GnRH agonists can be used for achievement of a temporary and reversible pseudomenopause for the treatment of endometriosis. 6 , 7 In the present study, we report the effects of intranasal administration of a potent agonistic analog of GnRH, nafarelin ([6-D-(2-naphthyl)-alanyl]-GnRH)8 on endometriosis in eight women treated for 6 months in whom laparoscopic evaluation of the endometriosis was performed before and after treatment. MATERIALS AND METHODS PATIENTS

Endometriosis was documented and photographed by laparoscopy before treatment in eight patients who were 25 to 37 years of age. The severity of the endometriosis in each patient was staged according to The American Fertility Society classification (Table 1).9 No operative therapeutic procedures were performed during the laparoscopy. Three patients had no previous treatment for their endometriosis. Five patients had had previous treatment with danazol, which had been terminated at least 3 months before the staging laparoscopy. Three patients had undergone previous conservative surgery for their endometriosis. All patients except one had painful symptoms of endometriosis. Two patients had rectal bleeding. A control group of untreated patients was not included in this study because both pretreatment and posttreatment diagnostic laparoscopy were required for clinical staging. Because endometriosis during the reproductive years is a progressive disease and does not spontaneously resolve, a second general anesthetic and surgical procedure could not be justified. PROTOCOL

Informed consent was obtained from all patients before enrollment in the study, which had 584

Schriock et al. GnRH analog therapy for endometriosis

been approved by the Committee on Human Research. Pretreatment evaluation included complete history and physical examination, Papanicolaou smear, complete blood count, blood chemistries, and urinalysis. All patients recorded their daily basal body temperatures and any vaginal bleeding and had blood drawn for progesterone (P), estradiol (E 2), LH, and FSH determinations weekly during 1 control month. All women were treated with 500 f.Lg of nafarelin by intranasal administration every 12 hours beginning during the first 3 days of their menstrual cycle. Hormonal analyses and measurements for nafarelin concentrations were performed on blood samples obtained before drug administration and 2, 4, and 8 hours after drug administration on treatment days 1, 15, and 30, and then monthly during treatment. Hormonal analyses also were performed on blood samples obtained every other day for 2 weeks, twice weekly for 2 weeks, and weekly thereafter for the remainder of the study. Complete blood count, serum chemistry, and urinalysis were monitored throughout the study. Patient compliance was monitored further by weekly assessment of serum nafarelin concentrations and periodic observation of the patient self-administering the drug. Women were examined and interviewed monthly for assessment of symptoms, and a severity profile of symptoms and physical findings was recorded (Table 1). Laparoscopy or laparotomy, with photography, and endometrial biopsy were performed after 6 months of treatment. Hormonal analyses were performed biweekly after completion of treatment until the first menstrual period. Serum LH and FSH concentrations were measured by radioimmunoassays (RIA) similar to those previously described.lO Gonadotropin concentrations are expressed in terms of milli-International Units of the Second International Reference Preparation for human menopausal gonadotropin (mIU-2nd-IRP-hMG). E2 concentrations were determined by RIA after purification by Celite chromatography.11 Serum concentrations of P were measured by RIA after hexane extraction. 11 Nafarelin was measured by RIA in the Department of Analytical and Metabolic Chemistry, Syntex Research, Palo Alto, California. 12 The antiserum used in this nafarelin RIA did not crossreact with native GnRH. The significance of changes in staging and severity profile was evaluated with the use of the nonparametric Wilcoxon t-test. Hormonal data Fertility and Sterility

Table 1. Clinical Findings During and After Treatment with Nafarelin Patient no. 1 2 3 4 5 6 7 8

Stage of disease" Before At termination treatment of treatmentd Extensive (34) Severe (16) Mild (3) Mild (2)e Moderate (7) Severe (28) Moderate (10) Mild (1)

Extensive (31) Moderate (6) Mild (1) Mild (2) Severe (22) Mild (5) Absent (0)

Active endometriosis b (implants only) Before At termination treatment of treatmentd 7 4 3 2e 4 5 9 1

4 0 1 0 0 0 0

Severity profile' Before At termination treatment of treatmentd 8 8 2 11 8 4 7 2

2 3 1 4 3 3 1 0

aStages within The American Fertility Society (AFS) classification are mild (1 to 5), moderate (6 to 15), severe (16 to 30), and extensive (31 to 54). The score is based on the size of the endometriomas and implants of endometriosis and the severity of adhesions involving the peritoneum, the ovary, and the fallopian tube. bPoints are based on the AFS classification considering only active disease as reflected by implants of endometriosis. cDerived by grading and assigning a numerical value to the symptoms of dysmenorrhea, dyspareunia, and pelvic pain and the physicaJ findings of pelvic tenderness and induration: absent = 0; mild = 1; moderate = 2; or severe = 3. The numbers were summed to create the severity profile (maximum score = 15). dpretreatment and posttreatment scores are significantly different: staging, P < 0.02; active endometriosis, P < 0.02; severity profile, P < 0.01. Residual adhesions accounted for most of the posttreatment staging scores and residual induration for most of the posttreatment severity profile scores. "Treatment was discontinued after only 2 months, and follow-up laparoscopy was not performed.

were analyzed by analysis of variance for repeated measures and the Neuman-Keuls rank order test. 13 All data, unless otherwise indicated, are expressed as mean ± 1 standard deviation.

RESULTS RESOLUTION OF ENDOMETRIOSIS

Seven of the eight women who completed the 6-month treatment course were examined surgically, five by laparoscopy and two by laparotomy. All women had a decrease in their clinical staging and active disease scores after therapy (P < 0.02, Table 1). Residual adhesions and a residual ovarian endometrioma accounted for most of the posttreatment staging scores. No endometrial implants were found after therapy in five of the seven patients. Patient 3 had a single, small endometriotic implant in the cul-de-sac after treatment. Patient 1 had persistent, active disease involving one fallopian tube and was the only woman with an ovarian endometrioma. The endometrioma, 6 cm in diameter, persisted throughout the study but decreased somewhat in size based on ultrasonic examination. In one patient (2) there was a significant decrease in the extent of adhesive disease after therapy. In two patients (5 and 6) there may have been a slight improvement in the degree of adhesive disease, although this apparent change may have been only a result of the error Vol. 44, No.5, November 1985

inherent in the clinical scoring procedure. All patients had complete loss or marked decrease in the painful symptoms of endometriosis during treatment (Table 1). Most women had significant symptomatic relief by 4 weeks of treatment, and improvement was maximal in all women by 12 weeks of treatment. Rectal bleeding completely resolved in the two patients with this complaint. HORMONAL RESPONSES

All women remained anovulatory during treatment. Vaginal bleeding during treatment was limited to spotting during the first month in six women and during the sixth month in one woman. Endometrial tissue obtained by biopsy at the conclusion of treatment was atrophic in one woman and proliferative in three women. In the remaining three women, sufficient tissue could not be obtained for histologic diagnosis. All women demonstrated marked increases in serum concentrations of LH and FSH after nafarelin administration on day 1 of treatment. LH reached mean peak concentrations of 169 ± 75 mIUlml (range, 102 to 354 mIUlml) 4 hours after 500 f.Lg of nafarelin, and FSH reached peak concentrations of 40 ± 12 mIUlml (range, 26 to 68 mIUlml) 4 to 8 hours after the medication. When reexamined after 2 weeks of treatment, the release of LH and FSH in response to nafarelin administration had decreased markedly and reSchriock et al. GnRH analog therapy for endometriosis

585

40

tions of nafarelin after intranasal administration were 0.45 ± 0.12 ng/ml after 2 hours, 0.26 ± 0.05 ng/ml after 4 hours, and 0.11 ± 0.01 ng/ml after 8 hours. Weekly assessment of basal concentrations of nafarelin drawn immediately before administration averaged 0.01 ± 0.03 ng/ml. The one patient (1) in whom serum E2 levels did not decline to the same degree as the other patients also had decreased basal concentrations of nafarelin (0.09 ± 0.11 ng/ml). Plasma concentrations of nafarelin in each patient were maintained throughout the study and decreased appropriately when the dosage of nafarelin was reduced.

20

ADVERSE REACTIONS

1

188 288 148

120

1

.....

e.....

100

CI

Q. ....,

...J

o

C 4( a: Ien

w

80 60

o

30

60

90

120

150

180

DA Y OF TREATMENT

Figure 1 Mean (± standard deviation) basal levels of E2 in eight women with endometriosis during treatment with nafarelin. For comparison, mean E2 concentrations in 12 postmenopausal women were 12.2 ± 4.1 pg/ml.

mained low throughout treatment. After the onset of treatment, concentrations of LH, determined in blood samples drawn immediately before nafarelin administration (basal concentrations), were elevated during the first 5 days of treatment but fell significantly within 2 weeks of treatment (P < 0.001), remaining low throughout the treatment regimen. Mean basal FSH concentrations during the initial treatment period were not significantly elevated and fell significantly (P < 0.001) within 2 weeks of treatment. After a transient increase in some patients during the initial month of treatment, mean E2 concentrations decreased to approximately menopausal concentrations « 30 pg/ml) by 4 weeks of treatment in all patients (Fig. 1). Once E2 concentrations decreased, there were no further elevations during treatment, with the exception of one patient (1) who had intermittent elevations of E 2 , which reached a maximum of 95 pg/ml during the sixth treatment month. This transient increase in E2 levels resulted in the only episode of bleeding after the first month of treatment. After minimal elevations of serum concentrations of P in some patients during the first few days of treatment, P levels remained < 0.5 ng/ml throughout the remainder of treatment. Mean serum concentra586

Schriock et al. GnRH analog therapy for endometriosis

All women developed symptoms of hypoestrogenemia. The major complaint was hot flashes, which became severe enough to necessitate decreasing the dose to 250 I-Lg twice daily in three women. Although decreasing the dosage resulted in subjective decreases in the severity of hot flashes in all three patients, E2 concentrations rose in only one patient. This elevation in E2 in response to one half the dose was transient, and E2 again fell to very low concentrations. Other complaints included vaginal dryness in four women, mild transient headaches in five, and mild transient depression in two. The effects of 6 months of hypoestrogenemia on bone density was not assessed. One patient was withdrawn from the study after 2 months of treatment because of the development ofleukopenia (nadir: 2500 white blood cells [WBC], with 55% polymorphonuclear leukocytes). This patient had become amenorrheic and had had a decrease in her painful symptoms of endometriosis before treatment was discontinued. Complete hematologic evaluation, which included bone marrow aspiration and biopsy, was normal. Subsequent WBC counts in this patient after treatment was discontinued remained at the lower limit of normal. The cause of her leukopenia could not be determined. REVERSIBILITY OF DRUG EFFECT

The mean number of days from discontinuation of treatment until the first ovulatory menses was 47 ± 8, with a range of 36 to 57. All symptoms of hypoestrogenemia resolved during the first month after treatment. All women except one reported decreased or absent dysmenorrhea immediately after treatment. However, either partial (n = 4) or complete (n = 2) recurrence of dysmenFertility and Sterility

orrhea occurred within 3 to 6 months after treatment. DISCUSSION

This study demonstrates that intranasal administration of a potent agonistic analog of GnRH can suppress gonadotropin secretion and thus inhibit ovulation and reduce ovarian E2 secretion to levels similar to those of postmenopausal women. This pseudomenopausal state produced prompt relief of the painful symptoms of endometriosis. Laparoscopy or laparotomy, performed both before and after 6 months of treatment, revealed complete resolution of active endometriotic lesions in five of seven patients and only a single, small cul-de-sac implant in the sixth woman. A large ovarian endometrioma in the seventh woman (patient 1) decreased only slightly after treatment, and there was persistent, active disease involving one fallopian tube. Dramatic changes in hormonal profiles were observed during nafarelin administration. Pituitary responsiveness to the agonist decreased markedly, and after a transition period in which basal LH levels were elevated, serum concentrations of FSH and LH were suppressed during treatment (P < 0.001) relative to pretreatment follicular phase levels. The most likely mechanism by which the analog inhibits ovarian function appears to be suppression of gonadotropin secretion, leading to decreased ovarian steroidogenesis. However, stimulation of the secretion of LH fragments with decreased bioactivity,14 ovarian desensitization to gonadotropin, or a direct inhibitory effect of the agonist on the ovary also is possible. 15 Variation ofE2 concentrations in individual patients was observed during the first few days after initiation of nafarelin treatment. A marked rise in E2 concentration during the first treatment month in one patient may have represented stimulation of early follicular development. This variable ovarian response to the transitory increase in gonadotropin secretion, however, did not result in ovulation in any of the patients. E2 concentrations were markedly suppressed « 30 pg/mD in all patients except one (patient 1). Plasma concentrations of nafarelin in this patient were lower than those of the other women, which suggests that reduced delivery or absorption or increased metabolism of nafarelin may have been responsible for the diminished ovarian suppression. A difference in sensitivity of Vol. 44, No.5, November 1985

this patient to nafarelin also may have been present, because another patient with similarly low plasma drug concentrations had markedly reduced serum E2 concentrations. The probable mechanism of action of GnRH agonist-induced resorption of endometriosis is estrogen deprivation and subsequent atrophy. The clinical response of patient 1 to GnRH agonist therapy supports this mechanism. In this patient; plasma E2 levels, in contrast to those of the other patients, were only moderately suppressed, and active disease involving one fallopian tube still was present at the completion of therapy. The effect of significant hypoestrogenemia for 6 months on bone density in young women is unknown and is presently under investigation. Recent nonhuman primate studies with intermittent GnRH agonist administration,16 however, suggest that markedly suppressed E2 concentrations may not be required for an adequate therapeutic effect in all patients. Moderate suppression of E2 may eliminate many of the symptoms and detrimental effects of marked hypoestrogenemia. Although serum E2 levels were significantly suppressed after 30 days of treatment in the present study, they were slightly higher than E2 concentrations in 12 untreated postmenopausal women (12.2 ± 4.1 pg/ml, P < 0.01). Reversibility of drug effect was prompt and complete. Thus, in addition to relieving symptoms of endometriosis, GnRH agonist therapy may be beneficial to the infertile woman who could conceive immediately after suppression of her endometriosis. Recurrence of symptoms in patients after treatment suggests that this treatment regimen induced a remission rather than a cure of endometriosis. The rate of recurrence in this study may be overestimated, however, because the study group consisted of patients who had severe endometriosis and were previous treatment failures. Treatment early in the course of the disease may be more beneficial. In summary, treatment of endometriosis with intranasal administration of a GnRH agonist (1) can decrease E2 concentrations to approximately menopausal levels, (2) can relieve symptoms of endometriosis, (3) can cause disappearance of endometriotic lesions, and (4) may be an alternative form of medical therapy for endometriosis. Clinical studies that involve a larger number of women with endometriosis are in progress to assess further the efficacy of agonistic analogs of GnRH in the treatment of this disorder. Future therapy Schriock et al. GnRH analog therapy for endometriosis

587

might be either short-term, high-dose treatment for infertility or long-term, low-dose treatment for amelioration of pain. Acknowledgments. We wish to thank Ms. Denise Bernstein, Ms. Deborah Downey, Ms. Mary Ellen LePage, and Ms. Alicia Sagasay for their excellent assistance in conducting this study. REFERENCES 1. Biberoglu KO, Behnnan SJ: Dosage aspects of danazol therapy in endometriosis: short-term and long-tenn effectiveness. Am J Obstet Gynecol 139:645, 1981 2. Buttram VC Jr, Belue JB, Reiter R: Interim report of a study of danazol for the treatment of endometriosis. Fertil Steril 37:478, 1982 3. Nillius SJ, Bergquist C, Wide L: Inhibition of ovulation in women by chronic treatment with a stimulatory LRH analogue. A new approach to birth control? Contraception 17:537, 1978 4. Meldrum DR, Pardridge WM, Karow WG, Rivier J, Vale W, Judd HL: Hormonal effects of danazol and medical oophorectomy in endometriosis. Obstet Gynecol 62:480, 1983 5. Meldrum DR, Chang RJ, LuJ, Vale W, RivierJ, Judd HL: "Medical oophorectomy" using a long-acting GnRH agonist: a possible new approach to the treatment of endometriosis. J Clin Endocrinol Metab 54:1081, 1982 6. Shaw RW, Fraser HM, Boyle H: Intranasal treatment with luteinizing hormone releasing hormone agonist in women with endometriosis. Br Med J 287:1667, 1983 7. Lemay A, Maheux R, Faure N, Jean C, Fazekas ATA: Reversible hypogonadism induced by a luteinizing hormone-releasing hormone (LH-RH) agonist (Buserelin) as a new therapeutic approach for endometriosis. Fertil Steril 41:863, 1984

588

Schriock et aI. GnRH analog therapy for endometriosis

8. Nestor JJ, Ho TL, Simpson RA, Horner BL, Jones GH, McRae GI, Vickery BH: Synthesis and biological activity of some very hydrophobic superagonist analogs of luteinizing honnone-releasing hormone. J Med Chem 25:795, 1982 9. American Fertility Society: Classification of endometriosis. Fertil Steril 32:633, 1979 10. Midgley AR Jr, Jaffe RB: Regulation of human gonadotropins. X. Episodic fluctuation of LH during the menstrual cycle. J Clin Endocrinol Metab 33:962, 1971 11. Abraham GE, Manlimos FS, Garza R: Radioimmunoassay of steroids. In Handbook of Radioimmunoassay, Edited by GE Abraham. New York, Marcel Dekker, Inc., 1977, p 591 12. Nerenberg C, Foreman J, Chu N, Kushinsky S: Radioimmunoassay of nafarelin ([6-(3-(2-naphthyl)-D-alanine))luteinizing honnone-releasing hormone) in plasma or serum. Anal Biochem 141:10, 1984 13. Winer BJ: Statistical Principles in Experimental Design. New York, McGraw-Hill, 1971, pp 195, 261 14. Meldrum DR, Tsao Z, Monroe SE, Braunstein GD, Sladek J, LuJKH, Vale W, RivierJ, Judd HL, Chang RJ: Stimulation of LH fragments with reduced bioactivity following GnRH agonist administration in women. J Clin Endocrinol Metab 58:755, 1984 15. Tureck RW, Mastroianni L, Blasco L, Strauss JF: Inhibition of human granulosa cell progesterone secretion by a gonadotropin-releasing hormone agonist. J Clin Endocrinol Metab 54:1078, 1982 16. Werlin LB, Hodgen GD: Gonadotropin-releasing hormone agonist suppresses ovulation, menses, and endometriosis in monkeys: an individualized, intennittent regimen. J Clin Endocrinol Metab 56:844, 1983

Fertility and Sterility