Goserelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical use in sex hormone-related conditions

Risk of ovarian hyperstimulation syndrome in women with malignancies undergoing treatment with long-acting gonadotropin-releasing hormone agonist after controlled ovarian hyperstimulation for fertility preservation: a systematic review

Background

Fertility preservation is an important quality of life issue for women of reproductive age undergoing gonadotoxic treatment. The possibility of administering an adjuvant long-acting gonadotropin-releasing hormone agonist (GnRHa) with the aim of reducing the number of follicles susceptible to the effects of chemotherapy and thus reducing the risk of ovarian damage is considered in some international society guidelines, particularly in certain cancers such as breast cancer. Nowadays, the administration of long-acting GnRHa after controlled ovarian hyperstimulation (COH) for fertility preservation by cryopreservation of oocytes or embryos is increasingly used. However, cases of ovarian hyperstimulation syndrome (OHSS) have been reported following the use of long-acting GnRHa after COH for fertility preservation, indicating that the potential adverse effects of this treatment need to be further investigated.

Objectives

The aim of this systematic review was to comprehensively characterize patients who developed OHSS after treatment with long-acting GnRHa following COH for fertility preservation.

Methods

A comprehensive search of major electronic databases through January 2023 was performed. Studies reporting the use of long-acting GnRHa after COH for fertility preservation and the development of OHSS were included. Risk of bias was assessed using a modified version of the Newcastle-Ottawa scale. Results were synthesized qualitatively.

Results

Three studies with five patients met the eligibility criteria. The majority of patients were diagnosed with breast cancer and all patients underwent COH for oocyte cryopreservation. OHSS occurred in all patients after administration of long-acting GnRHa. The interval between ovulation induction and administration of long-acting GnRHa thereafter ranged from 3 to 5 days. All patients were treated conservatively and recovered without complications.

Conclusion

Current evidence suggests that the use of long-acting GnRHa after COH for fertility preservation may be associated with OHSS. Healthcare providers should thoroughly discuss the benefits and risks of this intervention with their patients before making a decision. Further studies are needed to fully elucidate the causal relationship between long-acting GnRHa and OHSS in this population.

Pharmacological and toxicological studies of a novel goserelin acetate extended-release microspheres in rats

LY01005 is an investigational new drug product of goserelin acetate which is formulated as extended-release microspheres for intramuscular injection. To support the proposed clinical trials and marketing application of LY01005, pharmacodynamics, pharmacokinetics and toxicity studies were performed in rats. In the pharmacological study in rats, LY01005 induced an initial supra-physiological level increase of testosterone at 24 h post-dosing which then rapidly fell to castration level. The potency of LY01005 was comparable to the comparator Zoladex^® but its effect lasted longer and more stable. A single-dose pharmacokinetics study in rats demonstrated that the C_max and AUC_last of LY01005 increased in a dose-proportional manner in the range of 0.45-1.80 mg/kg and the relative bioavailability was 101.0% between LY01005 and Zoladex^®. In the toxicity study, almost all of the positive findings of LY01005 in rats including the changes in hormones (follicle-stimulating hormone, luteinizing hormone, testosterone, progestin) and in reproductive system (uterus, ovary, vagina, cervix uteri, mammary gland, testis, epididymis and prostate) were related to the direct pharmacological effects of goserelin. Mild histopathological changes in foreign body removal reaction induced by excipient were also observed. In conclusion, LY01005 displayed a sustained-release profile of goserelin, and exerted a continuous efficacy in vivo in animal models, which had a comparable potency but with a more sustained effect than that of Zoladex^®. The safety profile of LY01005 was largely the same with Zoladex^®. These results strongly support the planned LY01005 clinical trials.

Development and Validation of an LC-MS/MS Method for Simultaneous Determination of Short Peptide-Based Drugs in Human Blood Plasma

A novel HPLC-ESI-MS/MS method for simultaneous gonadotropin-releasing hormone (GnRH) analogs and somatostatin analog quantitation was developed and validated. The developed method was successfully applied to pharmacokinetic studies. The sample preparation process included solid-phase extraction (SPE). Effective chromatographic separation of the analytes and internal standard (dalargin) was achieved with a C18 column, using a gradient elution with two mobile phases: 0.1% v/v formic acid (aqueous solution) and 0.1% v/v formic acid (acetonitrile solution). The linearity of the method was demonstrated within a concentration range of 0.5-20 ng/mL, with correlation coefficients between 0.998-0.999 for goserelin, buserelin, triptorelin, and octreotide, respectively. The relative standard deviation (RSD, %) values for method accuracy and precision did not exceed 20% at the lower level of quantitation (LLOQ) or 15% at other concentration levels.

Hypothalamic connectivities predict individual differences in ADT-elicited changes in working memory and quality of life in prostate cancer patients

Androgen deprivation therapy (ADT) has been associated with adverse effects on cognition. However, we currently lack understanding of the neurobiology and prognostic markers of these effects. Given that ADT acts via the hypothalamus-pituitary-gonadal axis, we assessed whether baseline hypothalamic resting state functional connectivity (rsFC) could predict changes in working memory and quality of life in prostate cancer patients following androgen deprivation. In a prospective observational study, 28 men with non-metastatic prostate cancer receiving ADT and 38 patients not receiving ADT (controls), matched in age, years of education and Montreal Cognitive Assessment score, participated in brain imaging at baseline, and N-back task and quality-of-life (QoL) assessments at baseline and at 6 months follow-up. Imaging data were processed with published routines and evaluated at a corrected threshold. ADT and control groups did not differ in N-back performance or QoL across time points. In ADT, the changes in 0-back correct response rate (follow-up-baseline) were correlated with baseline hypothalamus-precentral gyrus rsFC; the changes in 1-back correct response rate and reaction time were each correlated with hypothalamus-middle frontal gyrus and superior parietal lobule rsFC. The changes in physical well-being subscore of QoL were correlated with baseline hypothalamus-anterior cingulate and cuneus rsFC. The hypothalamus rsFCs predicted N-back and QoL change with an area under the receiver operating characteristic curve of 0.93 and 0.73, respectively. Baseline hypothalamus-frontoparietal and salience network rsFC's predict inter-subject variations in the changes in working-memory and QoL following 6 months of ADT. Whether and how hypothalamic rsFCs may predict the cognitive and QoL effects with longer-term ADT remain to be investigated.

Severe ovarian hyperstimulation syndrome associated with long-acting GnRH agonist in oncofertility patients

PURPOSE

To report three cases of severe ovarian hyperstimulation syndrome (OHSS) among oncofertility patients receiving a long-acting GnRH agonist for ovarian suppression after controlled ovarian hyperstimulation (COH) with a GnRH antagonist protocol METHODS: Chart abstraction was completed for three patients at a single academic medical center. Patients included were undergoing fertility preservation prior to gonadotoxic chemotherapy. All patients underwent COH with GnRH antagonist protocol and embryo cryopreservation immediately followed by ovarian suppression with long-acting GnRH agonist. Main outcome measure was development of OHSS.

RESULTS

Despite using GnRH agonist trigger and freezing all embryos, patients developed ascites, intermittent hyponatremia and hemoconcentration consistent with severe early-onset OHSS after receiving long-acting GnRH agonist immediately following oocyte retrieval for ovarian preservation.

CONCLUSIONS

Risk of severe OHSS may be increased when a long-acting GnRH agonist is used for ovarian suppression immediately following oocyte retrieval. A delay in initiating long-acting GnRH agonist after oocyte retrieval in patients at high risk for developing OHSS should be considered.

Therapies Targeted to Androgen Receptor Signaling Axis in Prostate Cancer: Progress, Challenges, and Hope

Prostate cancer is the mostly commonly diagnosed non-cutaneous malignancy and the second leading cause of cancer-related death affecting men in the United States. Moreover, it disproportionately affects the men of African origin, who exhibit significantly greater incidence and mortality as compared to the men of European origin. Since androgens play an important role in the growth of normal prostate and prostate tumors, targeting of androgen signaling has remained a mainstay for the treatment of aggressive prostate cancer. Over the years, multiple approaches have been evaluated to effectively target the androgen signaling pathway that include direct targeting of the androgens, androgen receptor (AR), AR co-regulators or other alternate mechanisms that impact the outcome of androgen signaling. Several of these approaches are currently in clinical practice, while some are still pending further development and clinical evaluation. This remarkable progress has resulted from extensive laboratory, pre-clinical and clinical efforts, and mechanistic learnings from the therapeutic success and failures. In this review, we describe the importance of androgen signaling in prostate cancer biology and advances made over the years to effectively target this signaling pathway. We also discuss emerging data on the resistance pathways associated with the failure of various androgen signaling- targeted therapies and potential of this knowledge for translation into future therapies for prostate cancer.

Evolution of Targeted Therapy in Breast Cancer: Where Precision Medicine Began

As we consider best practices and approaches to targeted therapy in the clinic and in terms of trial design, breast cancer can serve as a useful model for other disease types, because estrogen receptor-positive and HER2-positive breast cancer have been known entities for several decades. In this review, we provide a history of the development of anti-estrogen therapy and anti-HER2-directed therapy and we discuss our growing understanding of resistance to targeted therapy as seen through this lens. We highlight some of the recent breakthroughs that have enhanced our understanding of resistance to endocrine and anti-HER2 therapy, and we discuss some of the ongoing research in the field.

Chemotherapeutic agents for the treatment of metastatic breast cancer: An update

Breast cancer is the second greatest cause of death among women worldwide; it comprises a group of heterogeneous diseases that evolves due to uncontrolled cellular growth and differentiation and the loss of normal programmed cell death. There are different molecular sub-types of breast cancer; therefore, various options are selected for treatment of different forms of metastatic breast cancer. However, the use of chemotherapeutic drugs is usually accompanied by deleterious side effects and the development of drug resistance when applied for a longer period. This review offers a classification of these chemotherapeutic agents according to their modes of action and therefore improves the understanding of molecular targets that are affected during treatment. Overall, it will allow the clinician to identify more specific targets to increase the effectiveness of a drug and to reduce general toxicity, resistance and other side effects.

Clinical pharmacology and regulatory consequences of GnRH analogues in prostate cancer

INTRODUCTION

GnRH (gonadotropin-releasing hormone) analogues are long-term known to be safe and effective in the clinical management of hormone-dependent advanced prostate cancer. However, their unusual mechanism of action of de-sensitizing pituitary receptors makes generic market entry challenging. In addition, safety aspects like initial flare-up, breakthrough escape, and miniflares render planning and organization of clinical registration trials a complex project.

REGULATORY REQUIREMENTS THERAPEUTIC EQUIVALENCE

Regulatory requirements are high as these medicines are compared to bilateral surgical castration with a 100% success rate. GnRH analogues will be used probably even wider in the near future due to demographic development and extension of indications. However, they are challenged by their antagonistic counterparts, which are avoiding flare-up phenomena. The following article deals with regulatory requirements of GnRH analogues in regard to their clinical characteristics.

Redefining hormone sensitive disease in advanced prostate cancer

Prostate cancer is the most common cancer among men in the United States. For decades, the cornerstone of medical treatment for advanced prostate cancer has been hormonal therapy, intended to lower testosterone levels, known as Androgen Deprivation Therapy (ADT). The development of hormone-resistant prostate cancer (now termed castration-resistant prostate cancer:CRPC) remains the key roadblock in successful long-term management of prostate cancer. New advancements in medical therapy for prostate cancer have added to the hormonal therapy armamentarium. These new therapeutic agents not only provide a survival benefit but also show potential for reversing hormonal resistance in metastatic CRPC, and thus redefining hormonally sensitive disease.

Development and validation of a liquid chromatography-tandem mass spectrometry method for the determination of goserelin in rabbit plasma

A rapid and sensitive liquid chromatography-electrospray ionization tandem mass spectrometry method (LC-ESI-MS/MS) was developed and validated for the determination of goserelin in rabbit plasma. Various parameters affecting plasma sample preparation, LC separation, and MS/MS detection were investigated, and optimized conditions were identified. Acidified plasma samples were applied to Oasis((R)) HLB solid-phase extraction (SPE) cartridges. Extracted samples were evaporated under a stream of nitrogen and then reconstituted with 100microL mobile phase A. The separation was achieved on a Capcell-Pak C18 (2.0mmx150mm, 5microm, AQ type) column with a gradient elution of solvent A (0.05% acetic acid in deionized water/acetonitrile=85/15; v/v) and solvent B (acetonitrile) at a flow rate of 250microL/min. The LC-MS/MS system was equipped with an electrospray ion source operating in positive ion mode. Multiple-reaction monitoring (MRM) of the precursor-product ion transitions consisted of m/z 635.7-->m/z 607.5 for goserelin and m/z 424.0-->m/z 292.1 for cephapirin (internal standard). The proposed method was validated by assessing specificity, linearity, limit of quantification (LOQ), intra- and inter-day precision and accuracy, recovery, and stability. Linear calibration curves were obtained in the concentration range of 0.1-20ng/mL (the correlation coefficients were above 0.99). The LOQ of the method was 0.1ng/mL. Results obtained from the validation study of goserelin showed good accuracy and precision at concentrations of 0.1, 1, 5, 10, and 20ng/mL. The validated method was successfully applied to a pharmacokinetic study of goserelin after a single subcutaneous injection of 3.6mg of goserelin in healthy white rabbits.

Quantification of buserelin in a pharmaceutical product by multiple-injection CZE

An efficient and rapid separation method based on reversed-polarity multiple-injection CZE (MICZE), has been developed for the quantification of buserelin in a pharmaceutical product. The determinations were performed by serially injecting five standard solutions of buserelin (50-300 microg/mL) and one reference analyte into a Polybrene-coated capillary. All the samples contained goserelin, an analog peptide to buserelin, as internal standard (IS). Immediately after pressure injection, the applied sample plugs were subjected to electrophoresis for 2 min at -25 kV. Consequently, each sample plug became isolated from its neighboring plugs by the BGE, composed of 100 mM phosphate-triethanolamine buffer at pH 3.0 containing 10% v/v ACN. During separation the individual sample components migrated at similar velocities and as distinct zones through the capillary giving 24 peaks, 12 from the analyte and the IS and 12 from the sample matrix. The buserelin content of the pharmaceutical product was determined to be 0.94 +/- 0.05 mg/mL, which is only a slight deviation from the declared concentration (1 mg/mL).

Luteinizing hormone-releasing hormone analogue-induced cataract in a patient with prostate cancer

OBJECTIVE

To report a case of right posterior subcapsular cataract induced by 3-monthly depot luteinizing hormone-releasing hormone (LHRH) analogue therapy in a patient with early prostate cancer.

CASE PRESENTATION

A 52-year-old male with static myopia of several years' duration was given a 3-month depot LHRH analogue (goserelin 10.8 mg) as part of neoadjuvant treatment for early prostate cancer. Four weeks after the treatment, the patient developed right posterior subcapsular cataract commonly associated with steroid treatment. The patient had right eye cataract extraction followed by insertion of a new lens.

CONCLUSION

This report shows a case of a posterior subcapsular cataract as an adverse reaction to depot goserelin acetate. This is a feature commonly seen in steroid-induced cataract. Patients with prostate cancer and poor vision if due to cataract may not be ideal patients for depot preparations of LHRH analogues.

Successful hormone treatment of orbital leiomyoma

PURPOSE

To describe the successful hormone treatment of noncircumscribed orbital leiomyoma.

DESIGN

Case report.

PARTICIPANT

A 66-year-old woman with histologically proven orbital leiomyoma.

METHODS

Because surgical excision of the tumor was impossible, therapy with the gonadotropin-releasing hormone (GnRH) analog goserelin was performed.

RESULTS

Hormone treatment was well tolerated and no side effects were noted. The tumor regressed significantly during treatment. No recurrence occurred during a 5-year follow-up period.

CONCLUSIONS

This report describes for the first time successful hormone treatment of a noncircumscribed orbital leiomyoma. Goserelin may have an antiproliferative effect on leiomyoma cells via membrane receptors for GnRH.

Goserelin

Goserelin (Zoladex), a gonadotropin-releasing hormone analogue, reduces plasma/serum estrogen levels in pre- or perimenopausal women (to postmenopausal levels), and is indicated in hormone receptor-positive early breast cancer in this population group. Adjuvant goserelin monotherapy has similar efficacy to adjuvant chemotherapy in pre- or perimenopausal women with early, hormone receptor-positive breast cancer. Furthermore, the addition of goserelin to adjuvant chemotherapy appeared to offer an advantage over chemotherapy alone in younger patients. Fewer patients remained amenorrheic after goserelin therapy than after chemotherapy. Complete endocrine blockade provided by the addition of tamoxifen to therapy including goserelin appears to improve outcomes. Thus, goserelin offers a valuable addition to the currently available options for treating pre- or perimenopausal women with hormone therapy-responsive early breast cancer, particularly for women wishing to regain ovarian function after treatment.

Comparative Study of Different Dosages of Goserelin in Size Reduction of Myomatous Uteri

STUDY OBJECTIVE

To compare uterine size reduction obtained with three monthly subcutaneous injections of 3.6 mg of goserelin versus a single subcutaneous injection of 10.8 mg.

DESIGN

Prospective, randomized clinical trial (Canadian Task Force classification I).

SETTING

Department of Gynecology and Obstetrics at the Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo.

PATIENTS

Forty-five premenopausal women with uterine leiomyomas and uterine size greater than 600 cm(3) randomized to one of two groups.

INTERVENTION

Group A: 23 women received three monthly subcutaneous 3.6-mg doses of goserelin. Group B: 22 women received a single subcutaneous injection of 10.8 mg of goserelin. Follicle-stimulating hormone (FSH), estradiol, and hemoglobin levels were measured monthly. After 3 months, uterine size was determined by transvaginal and/or abdominal ultrasound.

MEASUREMENTS AND MAIN RESULTS

In group A, mean reduction of uterine size was 43% (426 cm(3)) at the end of treatment. In Group B, mean reduction of uterine size was 54% (494 cm(3)). Serum levels of FSH and estradiol were in postmenopausal range during treatment. Hemoglobin level improvement was equivalent in both groups.

CONCLUSION

Use of single injection of 10.8 mg of goserelin promoted significantly greater reduction in uterine size than three monthly 3.6-mg injections in patients with voluminous uterine leiomyomas.

Diagnostic value of serum prostate-specific antigen in hemodialysis patients

BACKGROUND

The value of serum prostate-specific antigen (PSA) screening was examined to detect prostate cancer in men receiving hemodialysis.

METHODS

Forty-one male patients age 60-95 (median age, 70 years) receiving hemodialysis were investigated for PSA levels. We set the cut-off point at 4 ng/mL (the usual reference range). Digital rectal examination (DRE) and transrectal ultrasonography (TRUS) of the prostate were performed in patients whose PSA was more than 4 ng/mL and/or who expected further examination of the prostate. When prostate cancer was suspected, biopsy of the prostate was performed. In patients with prostate cancer, magnetic resonance imaging, computed tomography and bone scintigraphy were performed to diagnose the clinical stage.

RESULTS

The mean serum level of PSA was 2.10 +/- 0.49 ng/mL. In this screening study, four of 41 men required further examinations for prostate cancer. Two of four refused further examinations. The other two were diagnosed with prostate cancer. The incidence of prostate cancer was at least 5% in our hemodialysis patients. One man, whose clinical stage was T2aN0M0, was treated with radical retropubic prostatectomy. Another man, whose clinical stage was T2bN0M0, was treated with luteinizing hormone-releasing hormone analogue.

CONCLUSION

In our preliminary study, prostate cancer screening with PSA was useful for the early detection of prostate cancer in hemodialysis patients. If possible, DRE and TRUS should be performed in conjunction with PSA tests.

A benefit-risk assessment of medical treatment for uterine leiomyomas

The growth of a uterine leiomyoma growth stops and regresses after the menopause suggesting that leiomyoma growth is dependent on ovarian steroids. Therefore, estrogen has received much attention as the major factor responsible for the development of uterine leiomyomas, but progesterone also plays an important role in development of this disease. Cytogenetic analyses of resected samples has revealed that about 40 to 50% of leiomyomas show karyotypically detectable chromosomal abnormalities. Gonadotrophin releasing hormone (GnRH) agonists exert their action through the suppression of endogenous gonadotrophins and gonadal steroid secretion. Significant reductions of uterine/leiomyoma volume under GnRH agonist therapy has been reported in several studies. However, the leiomyoma generally returns to its pretreatment volume within a few months after discontinuation of the GnRH agonist. To minimise the adverse effects of hypoestrogenism during GnRH agonist treatment, add back therapy can be used (estrogen-progestin, progestin alone and recently tibolone). Antiprogestins have a potential clinical utility in uterine leiomyomas. Mifepristone is a synthetic steroid with both antiprogesterone and antiglucocorticoid activities, that may have an inhibitory effect on growth of leiomyoma. Danazol is an isoxazole of 17beta-ethinyl testosterone, a synthetic steroid, which has a suppressive effect on sex hormone binding globulin concentrations, resulting in efficacy in the short-term treatment of uterine leiomyomas. Gestrinone is a tri-enic steroid with antiestrogen and antiprogesterone properties and has been shown to reduce uterine volume and stop bleeding. Growth factors play a relevant role on the pathophysiology of uterine leiomyoma and probably the inhibition of the action of growth factors on the myometrium will be the basis for future therapy. A number of agents are under investigation for treating uterine leiomyoma. Agents developed from increasing genetic knowledge of this condition could represent, in the next few years, new trends in the medical treatment of uterine leiomyomas.

A comparative study of the acceptability and effect of goserelin and nafarelin on endometriosis

The effects of goserelin and nafarelin were compared in a prospective, randomized, open, parallel study of 6 months' treatment of 252 women with symptomatic, laparoscopically proven endometriosis. Twenty-eight departments of obstetrics and gynecology in Sweden, Norway, Denmark and Finland were included. Evaluations were made every 3 months for quantification of pain, bleeding and adverse events and convenience of treatment, and at 3 months after the end of treatment, when a control laparoscopy was performed for evaluation of changes in endometriotic lesion size, color and location. Thirty-nine patients withdrew and 113 women given goserelin and 100 women given nafarelin completed the study. There were no statistically significant differences between the groups, either in adverse events or in bleeding. There were no correlations between location, lesion size or type of lesion, and symptom score in either group, or between treatments with regard to change in endometriosis score. In both groups, the percentage of red and black lesions was reduced while the proportion of white lesions increased. The pain score was significantly reduced in both groups. Local irritation in the nasal mucosa was reported in both groups, mostly in the nafarelin-treated group. The goserelin-treated group also reported local symptoms at the injection site. We conclude that there is no statistically significant difference in treatment results or side-effects between goserelin and nafarelin when used for the treatment of endometriosis.

Clinical pharmacokinetics of goserelin

Goserelin is a synthetic decapeptide analogue of luteinising hormone-releasing hormone (LHRH). For experimental purposes it has been administered subcutaneously as an aqueous solution, but for therapeutic use it is formulated as subcutaneous depots releasing goserelin over periods of 1 (3.6 mg) or 3 (10.8 mg) months. Pharmacokinetic data have been generated using a specific radioimmunoassay. When administered as a solution, goserelin is rapidly absorbed and eliminated from serum with a mean elimination half-life (t1/2beta) of 4.2 hours in males and 2.3 hours in females. The shapes of the observed serum goserelin profiles following administration of the depots are primarily determined by the rate of goserelin release from the biodegradable lactide-glycolide copolymer matrix over periods of 1 or 3 months. There is no clinically relevant accumulation of goserelin during multiple administration of these depots. Goserelin is extensively metabolised prior to excretion. Its pharmacokinetics are unaffected by hepatic impairment, but the mean t1/2beta increases to 12.1 hours in patients with severe renal impairment. This suggests that the total renal clearance (renal metabolism and unchanged drug) is decreased in patients with renal dysfunction. It is unnecessary to adjust the dose or administration interval when the depot formulations are administered to elderly patients or to those with impaired renal or hepatic function. Administration of a goserelin 3.6 mg or 10.8 mg depot results in an initial increase of luteinising hormone (LH) levels and in increases of serum testosterone or oestradiol levels in males and females, respectively. This is followed by a decrease in serum LH levels and suppression of testosterone or oestradiol to within the castrate or menopausal range, respectively. Subsequently, throughout treatment with goserelin depots, serum testosterone or oestradiol levels remain suppressed. Clinical outcomes following treatment of patients with prostate cancer, breast cancer and benign gynaecological conditions with goserelin are described briefly.

Single-therapy androgen suppression in men with advanced prostate cancer: a systematic review and meta-analysis

PURPOSE

To compare luteinizing hormone-releasing hormone (LHRH) agonists with orchiectomy or diethylstilbestrol, and to compare antiandrogens with any of these three alternatives.

DATA SOURCES

A search of the MEDLINE, Cancerlit, EMBASE, and Cochrane Library databases from 1966 to March 1998 and Current Contents to 24 August 1998 for articles comparing the outcomes of the specified treatments. The search was limited to studies on prostatic neoplasms in humans. Total yield was 1477 studies.

STUDY SELECTION

Reports of efficacy outcomes were limited to randomized, controlled trials. Twenty-four trials involving more than 6600 patients, phase II studies that reported on withdrawals from therapy (the most reliable indicator of adverse effects), and all studies reporting on quality of life were abstracted.

DATA EXTRACTION

Two independent reviewers abstracted each article by following a prospectively designed protocol. The meta-analysis combined data on 2-year overall survival by using a random-effects model and; reported results as a hazard ratio relative to orchiectomy.

DATA SYNTHESIS

Ten trials of LHRH agonists involving 1908 patients reported no significant difference in overall survival. The hazard ratio showed LHRH agonists to be essentially equivalent to orchiectomy (hazard ratio, 1.1262 [corrected] [95% CI, 0.915 to 1.386]). There was no evidence of difference in overall survival among the LHRH agonists, although CIs were wider for leuprolide (hazard ratio, 1.0994 [CI, 0.207 to 5.835]) and buserelin (hazard ratio, 1.1315 [CI, 0.533 to 2.404]) than for goserelin (hazard ratio, 1.1172 [CI, 0.898 to 1.390]). Evidence from 8 trials involving 2717 patients suggests that nonsteroidal antiandrogens were associated with lower overall survival. The CI for the hazard ratio approached statistical significance (hazard ratio, 1.2158 [CI, 0.988 to 1.496]). Treatment withdrawals were less frequent with LHRH agonists (0% to 4%) than with nonsteroidal antiandrogens (4% to 10%).

CONCLUSIONS

Survival after therapy with an LHRH agonist was equivalent to that after orchiectomy. No evidence shows a difference in effectiveness among the LHRH agonists. Survival rates may be somewhat lower if a nonsteroidal antiandrogen is used as monotherapy.

Complete estrogen blockade for the treatment of metastatic and early stage breast cancer

Complete estrogen blockade has long been sought as a more effective means of controlling breast cancer compared with single agent endocrine therapy. This approach may be accomplished through the use of agents which reduce estrogen production combined with agents that prevent the activity of estrogen at the cellular level. For prostate cancer, another hormonally responsive malignancy, this approach has not been successful at improving survival compared with that achieved with single agent therapy. Preclinical information is contradictory for many promising combinations and may not reflect the true nature of in vivo interaction between agents. For premenopausal patients with metastatic breast cancer, the combination of a luteinising hormone-releasing hormone (LHRH) agonist and tamoxifen is clearly effective, but whether the combination is more effective than either single agent is still controversial. Similar response rates and overall survival were reported with goserelin or goserelin plus tamoxifen by Jonat et al. in 1 randomised, prospective study, but the addition of tamoxifen improved time to progression. A second trial comparing buserelin plus tamoxifen with either single agent reported superior efficacy in terms of response rates, disease-free survival and overall survival with combination therapy. A meta-analysis of 4 randomised trials making similar comparisons, demonstrated significant improvement in median overall survival, progression-free survival, response rate, and duration of response with the combination of a LHRH agonist (goserelin or buserelin) and tamoxifen in premenopausal breast cancer patients with metastatic disease. For postmenopausal women with metastatic breast cancer, the addition of an aromatase inhibitor to tamoxifen has yet to be prospectively compared to single agent therapy. Use of endocrine combinations in the treatment of early stage breast cancer is under investigation. Preliminary results of some of the ongoing adjuvant therapy trials indicate that the combination of a LHRH agonist and tamoxifen may have similar efficacy to cyclophosphamide, methotrexate, and fluorouracil chemotherapy in premenopausal women with estrogen receptor-positive tumour. Addition of LHRH agonist therapy in premenopausal patients with estrogen receptor-positive tumour who had maintained the ovarian function following chemotherapy [cyclophosphamide, doxorubicin (adriamycin), fluorouracil, and tamoxifen], also led to a reduction in the risk of recurrence. These studies have identified a sub-population of patients who may benefit from the addition of combination endocrine therapy. Overall, the issue is quite complex and the data from many ongoing trials are still awaited with anticipation to further delineate the role of complete estrogen deprivation in this disease.

Risk factors for ovarian failure in patients with systemic lupus erythematosus receiving cyclophosphamide therapy

OBJECTIVE

To determine the incidence of ovarian failure after cyclophosphamide (CYC) treatment for systemic lupus erythematosus (SLE) and to identify the risk factors for this complication.

METHODS

The records of 70 premenopausal female SLE patients treated with CYC were reviewed retrospectively. Information on demographic features, autoantibody profiles, and CYC treatment was obtained, and comparisons were made between those who developed ovarian failure and those who did not. Data on the CYC-treated patients were also compared with data on 2 control groups of non-CYC-treated SLE patients.

RESULTS

Eighteen patients developed ovarian failure after CYC treatment, for an overall incidence of 26%. The incidence of ovarian failure showed a linear trend of increase with increasing age at the start of CYC (P = 0.007). The cumulative CYC dose was significantly higher in the patients with ovarian failure than in those without (28.3 gm versus 15.4 gm; P = 0.004). The risk of ovarian failure also showed a linear trend of increase with increasing cumulative CYC dose (P < 0.001). Using multiple logistic regression, the age at the time of CYC treatment initiation (beta = 0.37, SE = 0.11, P = 0.001) and the cumulative dose of CYC received (beta = 0.69, SE = 0.29, P = 0.02) were found to be independent risk factors for CYC-induced ovarian failure.

CONCLUSION

In our population of female SLE patients, CYC-induced ovarian toxicity is a significant problem, particularly in patients above the age of 40. The age at the start of CYC therapy and the cumulative dose are the major determinants for the development of this complication. For older patients with SLE in whom the use of CYC is warranted, a shorter course and lower dosage should be considered.

Case report: systemic hypersensitivity reaction to goserelin acetate

Women suffering from endometriosis are treated with long-acting analogues of gonadotropin-releasing hormone (GnRH). This is a case of hypersensitivity reaction to a goserelin acetate implant that manifested as an anaphylactic reaction. This is the first report of a hypersensitivity reaction to the GnRH analogue, goserelin acetate (Zoladex, Zeneca Pharmaceuticals, Wilmington, DE).

Incidence of ovarian failure in systemic lupus erythematosus after treatment with pulse cyclophosphamide

OBJECTIVE

To investigate the incidence of ovarian failure after pulse cyclophosphamide treatment in systemic lupus erythematosus (SLE) and to compare this with two control groups: SLE patients treated with azathioprine, and a healthy age matched population.

METHODS

All women patients with SLE treated with pulse cyclophosphamide in our department were identified and questioned concerning menstrual history. All the hospital notes were reviewed and details recorded on dose of cyclophosphamide, duration of treatment, side effects and lowest pretreatment neutrophil and leucocyte counts during the course of treatment. Disease controls were recruited from our department and healthy controls from the local family health services authority (FHSA) register.

RESULTS

Incidence of ovarian failure in the premenopausal cyclophosphamide treated group was 54% and the incidence of premature menopause (occurring before age 40 years) was 41%. Increasing age at start of treatment showed a linear trend with incidence of ovarian failure (p = 0.01). Using logistic regression, increasing duration of treatment was related to incidence of ovarian failure (p = 0.047 in those treated age 35 years or younger). An association between the lowest neutrophil count throughout the treatment period, when taken immediately before each planned cyclophosphamide pulse, and the incidence of ovarian failure was also demonstrated (p = 0.04 in those treated before age 40 years).

CONCLUSION

Ovarian failure--in particular, premature failure after treatment with pulse cyclophosphamide--is common. Factors associated with increased risk include greater age at start of treatment, longer period of treatment, and greater degree of marrow suppression as assessed by the neutrophil count immediately before each planned cyclophosphamide pulse.

Leuprorelin. A review of its pharmacology and therapeutic use in prostatic cancer, endometriosis and other sex hormone-related disorders

Leuprorelin (leuprolide acetate) is a gonadotrophin-releasing hormone (GnRH) analogue used to treat a wide range of sex hormone-related disorders including advanced prostatic cancer, endometriosis and precocious puberty. It acts primarily on the anterior pituitary, inducing a transient early rise in gonadotrophin release. With continued use, leuprorelin causes pituitary desensitisation and/or down-regulation, leading to suppressed circulating levels of gonadotrophins and sex hormones. Clinical trials in men with advanced prostatic cancer demonstrate that leuprorelin (usually monthly depot injections of 3.75 or 7.5 mg) is less likely to cause serious adverse cardiovascular effects than diethylstilbestrol, and has comparable efficacy to bilateral orchiectomy or other GnRH analogues. Therefore, the choice between leuprorelin and orchiectomy may be made on the basis of the patient's treatment preference, along with specific patient characteristics and cost implications. Monthly intramuscular or subcutaneous administration of depot leuprorelin 3.75 mg was superior to placebo, and comparable to oral danazol 800 mg/day or intranasal buserelin 900 micrograms/day, in achieving objective and subjective responses in women with endometriosis. Thus, leuprorelin is an effective alternative to other treatments for women with endometriosis, but the recommended duration of its use in this clinical setting is limited to 6 months because it reduces bone mineral density. In children with central precocious puberty, leuprorelin (usually monthly intramuscular or subcutaneous injections of depot leuprorelin 3.75 to 15mg) decreases mean growth velocity and signs of sexual maturation and increases predicted adult height compared with baseline measurements. Although effects on final adult height are predicted from available data and require confirmation in long term follow-up studies, the absence of effective alternatives to GnRH analogues makes leuprorelin a first-line therapy for children with this rare disease. In women with uterine leiomyomata, monthly intramuscular administration of depot leuprorelin 3.75 mg for 6 months markedly reduces uterine volume and fibroid-related symptoms, but, as with other GnRH analogues, these effects dissipate following discontinuation of the drug. As adjuvant therapy in women undergoing in vitro fertilisation or gamete intrafallopian transfer, leuprorelin (usually 0.5 to 1 mg/day subcutaneously) reduces the risk of cancelled cycles for oocyte retrieval by preventing premature luteinisation. While some studies demonstrate an improvement in intermediate end-points such as increased number of mature oocytes retrieved and embryos available for transfer, a significant effect has not been demonstrated on the rate of live births per stimulated cycle.(ABSTRACT TRUNCATED AT 400 WORDS)

Impact of different GnRH analogs in benign gynecological disorders related to their chemical structure, delivery systems and dose

This review addresses the question of whether the different gonadotropin releasing hormone (GnRH) agonists in clinical use might have different impacts, related to their chemical structure, delivery system and dose. Impact was investigated in benign gynecological disorders, i.e. endometriosis and leiomyoma. Arguments are presented indicating that a difference in impact of different analogs can be expected. All currently used intranasal, daily subcutaneous and depot preparations finally give rise to low levels of serum estradiol. The number of days before the first ovulatory menstruation after discontinuation of GnRH agonist treatment is remarkably constant. Four weeks after the last impact of the agonist, there is resumption of follicle growth. This phenomenon is independent of chemical structure, delivery system and dose. One should realize, however, that it generally takes about 30 days before the impact of a depot preparation disappears. Consequently, the impact of a depot preparation lasts 4 weeks longer than that of an otherwise applied agonist. Thus resumption of pituitary activity after discontinuation of a depot formulation takes 4 weeks longer than after discontinuation of non-depot formulations. All agonists have an impressive effect on endometriosis, independent of their chemical structure and delivery system. However, there are no studies comparing different agonists with the same delivery system in comparable endometriosis groups. Similarly, all agonists considerably reduce myoma volume, independently of their chemical structure and delivery system.(ABSTRACT TRUNCATED AT 250 WORDS)

Biodegradable microspheres containing a colchicine analogue inhibit DNA synthesis in vascular smooth muscle cells

BACKGROUND

Smooth muscle cell proliferation plays a major role in the genesis of restenosis after angioplasty or vascular injury. Local application of agents capable of modulating vascular responses, including smooth muscle cell proliferation, has been achieved, but difficulty in maintaining active levels locally has been a factor limiting the efficacy of such approaches. One strategy to maintain adequate levels is the local delivery of microspheres that release active agents over sustained time periods.

METHODS AND RESULTS

We incorporated a colchicine analogue into biodegradable microspheres composed of a lactic acid/glycolic acid copolymer and characterized their drug release behavior as well as their effects on bovine aortic smooth muscle cells (BASMCs) in culture. Drug release was evaluated by spectrophotometric assay. Drug effects on DNA synthesis were measured by thymidine incorporation after addition of serum to subconfluent cells synchronized by serum withdrawal as well as in asynchronous cell populations. Polymeric microspheres incorporating 10% to 17% drug by weight and averaging 6 microns in size were found to release the colchicine analog in buffered saline solutions over more than several weeks. Drug-loaded particles inhibited DNA synthesis completely, with EC50 values ranging from 0.001 to 0.005 g% (wt/wt). Morphological changes suggesting microtubule depolymerization were observed after drug particle treatment, with similar EC50 values. Microspheres allowed to contact the cell surface demonstrated effects similar to those seen with microspheres suspended in the nutrient medium by porous polycarbonate filters, at EC50 values approximately fivefold lower. In contrast, control microspheres composed only of polymer with no incorporated active drug demonstrated no observable toxicity to BASMCs and < 40% inhibition of thymidine incorporation even in suspensions containing up to 0.5 g% particles.

CONCLUSIONS

Biodegradable microspheres were fashioned that release a colchicine analogue and inhibit DNA synthesis in smooth muscle cells. Drug-loaded polymeric particles are candidates for local delivery at sites of arterial injury to decrease restenosis.

Histrelin. A review of its pharmacological properties and therapeutic role in central precocious puberty

Histrelin is a synthetic gonadotrophin-releasing hormone (GnRH) agonist which, when administered over a prolonged period, suppresses the release of gonadotrophins from the anterior pituitary. Data from clinical trials undertaken in small numbers of patients with idiopathic central precocious puberty have demonstrated that histrelin 8 to 10 micrograms/kg/day administered subcutaneously desensitises the anterior pituitary to gonadotrophin secretion within 3 months, ablating the pubertal gonadotrophin response to GnRH stimulation and reducing circulating gonadal sex steroid levels. When histrelin is administered to treat central precocious puberty, the rate of secondary sexual maturation is slowed and in some cases there is a reversal of maturation which occurs before initiation of treatment. Of equal importance, histrelin therapy appears to have decelerating effects on skeletal maturation, allowing more statural growth; an increase in final adult height is predicted from available data, but will need to be confirmed in long term follow-up studies currently being undertaken. The most common adverse event reported during histrelin therapy was a skin reaction at the site of subcutaneous injection. Few patients have discontinued therapy because of any adverse event. Although experience with histrelin is limited, the absence of effective clinically available alternatives and the demonstrated efficacy of histrelin justifies its place as a first-line therapy for patients with central precocious puberty.