Leuprorelin acetate depot: results of a multicentre Japanese trial. TAP-144-SR Study Group

Predictive clinical indicators of biochemical progression in advanced prostate cancer patients receiving Leuplin depot as androgen deprivation therapy

Therapeutic planning and counseling for advanced prostate cancer patients receiving androgen deprivation therapy (ADT) is complicated because the prognoses are highly variable. The purpose of this study is to identify predictive clinical indicators of biochemical progression (BCP). In this retrospective analysis, data from 107 newly diagnosed patients (from November 1995 to April 2008) with advanced prostate adenocarcinoma receiving Leuprorelin acetate depot were analyzed. Data was collected from the computerized registry of two collaborating medical centers in Taiwan. Cox regression and Kaplan-Meier analyses were used to evaluate the relationship between potential predictive parameters and BCP. Univariate analysis revealed that predictors of BCP included (1) initial serum prostate-specific antigen (PSA) (hazard ratio [HR], 1.00; 95% confidence interval [CI] 1.00–1.00); (2) log of initial PSA (HR, 1.35; 95% CI 1.17–1.56); (3) PSA density at diagnosis (HR, 1.00; 95% CI 1.00–1.01), and (4) pathological bone fracture (HR, 2.22; 95% CI 1.20–4.11). Age (HR, 0.94; 95% CI 0.91–0.98) and hemoglobin levels (HR, 0.86; 95% CI 0.76–0.97) were also associated with greater risk of BCP. After adjusting for age, pathologic fracture, and hemoglobin level, the initial PSA and PSA density were no longer significantly associated with BCP. However, age and hemoglobin levels continued to be associated with greater risk of BCP (P≤0.007). Using Kaplan-Meier analysis, patients with higher initial PSA concentration, pathological bone fracture, and low hemoglobin had a greater probability of BCP. Thus, low hemoglobin and age are predictive indicators of BCP and therefore early indicators of BCP despite ADT therapy.

Management of menorrhagia associated with chemotherapy-induced thrombocytopenia in women with hematologic malignancy

Abnormal uterine bleeding in women with a blood dyscrasia, such as leukemia, or who experience thrombocytopenia secondary to myelosuppressive chemotherapy is a clinical condition associated with significant morbidity. Consequently, effective management is necessary to prevent adverse outcomes. Prevention of menorrhagia, defined as heavy regular menstrual cycles with more than 80 ml of blood loss/cycle or a cycle duration longer than 7 days, in this patient population is the goal of therapy. Gonadotropin-releasing hormone analogs (e.g., leuprolide) are promising therapies that have been shown to decrease vaginal bleeding during periods of thrombocytopenia and to have minimal adverse effects other than those associated with gonadal inhibition. In patients who experience menorrhagia despite preventive therapies, or in patients who have thrombocytopenia and menorrhagia at diagnosis, treatment is indicated. For these women, treatment options may include platelet transfusions, antifibrinolytic therapy (e.g., tranexamic acid), continuous high-dose oral contraceptives, cyclic progestins, or other therapies for more refractory patients such as danazol, desmopressin, and recombinant factor VIIa. Hormonal therapies are often the mainstay of therapy in women with menorrhagia secondary to thrombocytopenia, but data for these agents are sparse. The most robust data for the treatment of menorrhagia are for tranexamic acid. Most women receiving tranexamic acid in randomized trials experienced meaningful reductions in menstrual bleeding, and this translated into improved quality of life; however, these trials were not performed in patients with cancer. Further clinical trials are warranted to evaluate both preventive and therapeutic agents for menorrhagia in premenopausal women with cancer who are receiving myelosuppressive chemotherapy.

Obesity and sex steroids during gonadotropin-releasing hormone agonist treatment for prostate cancer

PURPOSE

To evaluate effects of obesity on sex steroid levels during treatment with a gonadotropin-releasing hormone agonist in men with prostate cancer.

EXPERIMENTAL DESIGN

Forty-nine hormone-naïve men with recurrent or locally advanced prostate cancer were included in the analyses. All subjects were treated with leuprolide 3-month depot for 48 weeks. Serum levels of estradiol, sex hormone-binding globulin, total testosterone, and free testosterone were assessed at baseline, 24 weeks, and 48 weeks. Subjects were categorized by body mass index (BMI) and percent body fat.

RESULTS

Pretreatment serum sex hormone-binding globulin and total testosterone levels were significantly lower in overweight and obese men than in men with normal BMI. In the overall study population, mean serum testosterone concentrations decreased from 372 +/- 18 ng/dL at baseline to 13 +/- 1 ng/dL at week 48 (P < 0.001). Free testosterone decreased from 6.75 +/- 0.33 ng/dL at baseline to 0.21 +/- 0.02 ng/dL at week 48 (P < 0.001). During treatment with leuprolide, obese men had significantly higher total and free testosterone levels than men with normal BMI. Compared with normal men, total and free testosterone levels during treatment were 1.8-fold and 2.3-fold higher in obese men. Similar results were observed when subjects were categorized by body fat.

CONCLUSIONS

Despite lower pretreatment serum testosterone levels, obese men have higher total and free testosterone levels during leuprolide treatment than men with normal BMI. These differences may contribute to the association between obesity and increased prostate cancer mortality.

One- and three-month release injectable microspheres of the LH-RH superagonist leuprorelin acetate

The biodegradable polymers poly(lactic/glycolic acid) (PLGA) and poly(lactic acid) (PLA) were used as wall materials in the preparation of microspheres (msp) containing the LH-RH superagonist leuprorelin (leuprolide) acetate. A novel W/O/W emulsion-solvent evaporation method was devised for the preparation of msp containing this water-soluble peptide. This method achieved high entrapment efficiency and sustained drug release over a long period predominantly due to polymer bioerosion. The msp are fine microcapsules with polycores containing the peptide at a high concentration and are easily injectable through a conventional fine needle. Leuprorelin msp made with PLGA(75/25)-14,000 or PLA-15,000 released the drug in a zero-order fashion, maintained constant serum drug levels and attained persistent objective suppression of the pituitary-gonadal system ('chemical castration') over 1 or 3 months after i.m. or s.c. injection into animals. These results indicate that depot formulations may be potentially useful in the therapy of endocrine diseases in humans. In this paper, studies on the formulation, drug release and pharmacological effects in animals for these leuprorelin depot formulations are reviewed.

Therapeutic effects of leuprorelin microspheres in prostate cancer

Leuprorelin has demonstrated effectiveness comparable to orchiectomy and oral diethylstilboestrol for the palliation of advanced prostate cancer. Unlike orchiectomy, leuprorelin's effects are reversible; also leuprorelin is not associated with the cardiovascular or thromboembolic adverse effects of oestrogens. For these reasons, leuprorelin has been widely used as an alternative to surgical castration or to oestrogens in the treatment of metastatic prostate cancer. Sustained-release leuprorelin microsphere formulations have been developed which exhibit zero order release of active drug from the injection site, such that in the United States the 7.5 mg dosage strength is recommended to be administered once a month and the 22.5 mg dosage strength once every three months. Although most patients will have suppressed release of pituitary luteinizing hormone by the third or fourth week after the first dose of depot leuprorelin, 4-5% of treated patients have been reported to have delayed responses, taking many more weeks or months to respond. A transient biochemical hormone escape has also been reported, although worsening of clinical symptoms has not accompanied the elevation of serum testosterone levels during treatment. Usually, leuprorelin is initiated as monotherapy when patients with advanced prostate cancer become symptomatic. However, newer studies of combination therapy of luteinizing hormone releasing hormone analogs with antiandrogens suggest that early initiation of therapy, at the time of diagnosis of advanced disease, may be beneficial, particularly in a subgroup of patients with small volume disease and good performance status. Leuprorelin is also undergoing evaluation as neoadjuvant therapy prior to radical prostatectomy for localized prostate cancer. Preliminary studies suggest that neoadjuvant leuprorelin in combination with an antiandrogen may be effective in downstaging prostate tumours. Leuprorelin commonly produces several adverse effects: hot flashes, decreased libido and impotence, and tumour flare.

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)