Aromatase inhibition by delta 1-testolactone does not relieve the gonadotropin-induced late steroidogenic block in normal men

Fadrozole HCL (CGS-16949A) versus megestrol acetate treatment of postmenopausal patients with metastatic breast carcinoma: results of two randomized double blind controlled multiinstitutional trials

BACKGROUND

Breast cancer patients with prior response to endocrine therapy achieve subsequent benefit from additional endocrine therapies. The efficacy and safety of an aromatase inhibitor, fadrozole HCL, were compared with megestrol acetate in post menopausal patients who had disease progression after receiving antiestrogen therapy either for metastatic disease or as adjuvant therapy.

METHODS

In 2 multiinstitutional prospective trials, 683 postmenopausal patients were randomized to receive either fadrozole HCL, 1 mg twice daily, or megestrol acetate, 40 mg 4 times daily, in a double blind fashion after progression on first-line hormonal therapy. Objective response rates, time to progression, survival and safety of the two regimens were compared.

RESULTS

Results of intent-to-treat analyses are presented in this study. No significant differences were detected between the two treatment groups in time to progression, objective response rates, duration of response, and survival in either trial. There were no clinically meaningful differences between the treatment groups in the incidence and severity of adverse experiences, except that weight gain, fluid retention, and dyspnea were observed in more patients in the megestrol acetate group compared with those receiving fadrozole HCL, whereas nausea and vomiting were observed in more patients in the fadrozole HCL group compared with those receiving megestrol acetate.

CONCLUSIONS

Fadrozole HCL was as efficacious as megestrol acetate in postmenopausal patients with metastatic breast carcinoma after one hormonal therapy. Adverse experiences were mild with both therapies, but megestrol acetate was associated wiht a higher frequency of weight gain, fluid retention and dyspnea, whereas fadrozole HCL was associated with a higher frequency of nausea and vomiting.

High-density lipoprotein cholesterol is not decreased if an aromatizable androgen is administered

We examined the influence of aromatization of testosterone on serum high-density lipoprotein cholesterol (HDL-C) and postheparin plasma hepatic triglyceride lipase activity (HTLA) in men. Eighteen healthy lean nonsmokers (ages, 20 to 33) were administered androgens in a weekly total dose of 280 mg for 12 weeks in one of three groups: testosterone enanthate (TE) (280 mg/wk intramuscularly [IM]); TE (280 mg/wk IM) + testolactone (TL) (250 mg orally [PO] four times daily); or methyltestosterone (MeT) (20 mg PO twice daily). Serum testosterone achieved steady state levels by 4 weeks with greater than 40 nmol/L (TE and TE + TL) and less than 15 nmol/L (MeT) while 17b-estradiol (E2) rose to greater than 250 pmol/L (TE) or remained below 70 pmol/L (TE + TL and MeT). LH fell to less than 5 U/L (TE and TE + TL) but remained unchanged with MeT. By 4 weeks, HDL-C had decreased significantly from 1.20 +/- 0.13 to 0.77 +/- 0.13 mmol/L (MeT), from 1.18 +/- 0.15 to 0.89 +/- 0.13 mmol/L (TE TL), and demonstrated no decrease in the TE group across the time course of the study. These changes were preceded by mean increases in HTLA of 102% (MeT) and 55% (TE + TL) over baseline, and no significant change with TE. The changes in HDL-C and HTLA returned to baseline within 2 weeks of steroid cessation. There were no changes in total cholesterol, triglycerides, or insulin in any group but, in the MeT group, apo AI levels decreased and low-density lipoprotein cholesterol (LDL-C) increased.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of men with idiopathic oligozoospermic infertility using the aromatase inhibitor, testolactone. Results of a double-blinded, randomized, placebo-controlled trial with crossover

The hypothesis that increased estradiol production may be the cause of impaired spermatogenesis in infertile men with idiopathic oligozoospermia was tested by administering the aromatase inhibitor, testolactone, and by assessing its effects on sperm output and fertility. Our study was a randomized, placebo-controlled double-blind crossover trial. Subjects (n = 25) with infertility due to unexplained oligozoospermia were given testolactone (2 g/day) or placebo for 8 months followed by crossover to the other treatment for an additional 8 months. Total estradiol and testosterone levels during testolactone exposure did not change from basal and placebo values. However, sex hormone-binding globulin binding capacity consistently decreased (30%, p less than 0.01) and free testosterone levels increased (36%, p less than 0.01). Free estradiol values increased but not significantly. Additionally, LH and FSH serum levels increased by 15% and 20%, respectively (p less than 0.05), and 17 alpha-hydroxyprogesterone values increased by 90% (p less than 0.05) during drug administration. Sperm output and semen quality remained unchanged during either testolactone or placebo treatment, and no pregnancies occurred during the 16-month study. These data suggest that chronic administration of testolactone at this dose fails to maintain aromatase inhibition despite depression of 17,20-desmolase activity with elevated 17 alpha-hydroxyprogesterone and depressed SHBG binding capacity with elevation of free testosterone. Testolactone is not efficacious in the treatment of idiopathic oligozoospermic infertility.

Reciprocal inhibition of the long-acting luteinizing hormone releasing hormone agonist Buserelin and human chorionic gonadotropin in stimulating Leydig cell steroidogenesis

The interference between human chorionic gonadotropin (hCG, Pregnyl, Organon 1500 IU i.m.) and the long acting LHRH agonist Buserelin (500 micrograms s.c.) in stimulating Leydig cell steroidogenesis was studied in 6 eugonadal men. Simultaneous administration of a single injection of the agonist (LHRH alpha) and hCG blunted the plasma testosterone response observed 24 h after LHRH alpha alone, enhanced the secretion of oestradiol without affecting 17-hydroxy-progesterone and aggravated the late steroidogenic block at the 17,20-lyase locus. As compared to hCG alone, combined LHRH alpha and hCG administration also decreased the maximum and 48 h testosterone increments and the testosterone production reflected by the area under the curve, enhanced the production of oestradiol and again aggravated the 17,20-lyase lesion. The data show that the long acting agonist LHRH alpha and hCG reciprocally inhibit their stimulatory effect on Leydig cell testosterone secretion probably by a suppressive effect of oestrogens on the conversion of C21- to C19-steroids. The mechanism underlying this reciprocal inhibition remains to be elucidated.