Description

The hormonal changes occurring in perimenopause and menopause exert multiple effects on several organs and the accompanied symptoms can be very distressing and impair quality of life. Vasomotor symptoms (VMS) defined as hot flashes and sweating are the most frequent and bothersome symptoms of menopause and are experienced by up to 80% of women. Additionally, in the Western world, 66% of postmenopausal women are obese and 54% have osteoporosis. Along with obesity comes a wide variety of health issues such as type 2 diabetes, metabolic syndrome, and atherosclerosis, which can lead to cardiovascular disease. Osteoporosis is a huge economic cost for society, it impairs quality of life and vertebral and hip fractures are associated with increased mortality. Postmenopausal symptoms and complications take a large toll on both the physical and mental well-being of women and are a huge cost to society. Menopausal Hormonal Therapy (MHT) with estrogen and gestagen is used by many women as it alleviates symptoms and reduces the risk of osteoporosis and cardiovascular disease. However, due to the increased risk of breast cancer and venous thromboembolism, some women refuse MHT and there is an ongoing search for new treatments. The newly approved Veoza® (Fezolinetant) is also approved and on the marked, but only targets VMS and not menopausal complications, but can be a treatment option, if the woman can or will not have MHT.

Menopause is characterized by low circulating estrogen, but also by very high levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and these hormonal changes are linked with increased bone resorption and weight gain. Despite the high LH in menopause, LH pulses occur simultaneously with hot flashes also in postmenopausal women, and LH may be involved in the events. In a clinical study 10 postmenopausal women with severe VMS were given a GnRH antagonist cetrorelix 250 μg two times a day in 6 weeks. They found a significant decrease in VMS symptoms. Postmenopausal women experience a decline in core temperature, which we suggest is due to LH actions on brown and white fat cells leading to less heat generation, beta-oxidation, and more storing of fat. Furthermore, LH appears to be a rapid and potent inducer of renal calcium excretion, which induces a secondary and persistent increase in parathyroid hormone (PTH) that mobilizes calcium from the skeleton. The LH-induced calcium excretion occurs several hours before the subsequent changes in sex steroids, particularly estrogen, which indicates a direct effect of LH that can lead to increased bone resorption and eventually osteoporosis. This may be of great importance during the perimenopause/early phase of menopause, where the decrease in bone mineral density and increase in visceral adiposity is high concurrent with serum LH increasing dramatically, while serum estrogen is still not greatly reduced. The investigators propose to investigate if lowering LH using a gonadotropin releasing hormone (GnRH) analog against placebo can improve bone markers and secondarily reduce the frequency and severity of VMS in postmenopausal women with a direct comparison to estrogen - the gold standard treatment of women in menopause, and testosterone in the same RCT.

The main aim of the study is to show that by targeting LH the investigators can change bone markers and maybe even combat hot flashes and night sweats (VMS) in postmenopausal women. For important biological knowledge purpose, the investigators also investigate the 2 additional treatment arms with estradiol and testosterone to compare the effect against the current gold standard treatment option (estradiol) and to testosterone, which is a common supplement to postmenopausal women off-label. A study by Glaser et al. effectively documents that testosterone can improve most common post-menopausal symptoms.

Sample size calculation and statistics Previous studies have shown that CTX in postmenopausal women is usually between 0.44 ng/mL with a standard diviation on SD 0.2. The sample size is calculated based on a direct comparison between GnRH analog (pamorelin) and placebo on the primary outcome 'change in bone markers' (delta CTX between pamorelin and placebo), using a power of 80% and alpha of 0.05 leads to 44 participants in each group, and the investigators would be able to detect a change in CTX on 30 %. The calculations is based on only two arms, however for comparison reasons the investigators will include two extra arms with estradiol/testosterone and patients will be allocated 1:1:1:1 leading to a total sample size of 176 participants. Our design and analysis principles rely on the intent-to-treat (ITT) approach; the investigators strive to evaluate and include all randomized participants in the primary analysis, regardless of adherence to treatment assignment or protocol requirements.

The investigators estimate to screen 250 to include 192 to be randomized and 176 to complete the study leaving 16 patients for dropout (9%). The design enables us to investigate multiple secondary outcomes where the primary comparison will be between GnRH analog treatment and placebo. The study is not powered to show significant differences between placebo and GnRH treatment for most secondary endpoints and should be considered as a pilot placebo-controlled intervention study for these outcomes. T-tests will be used for the primary endpoint, while Nonresponder imputation will be used for missing response data. Change in mean frequency and severity of VMS per 24 hours will be analyzed for each week using a mixed effect model for repeated measures, with change from baseline as the dependent variable and treatment group, visit, and smoking status as factors and baseline measurement as a covariate, as well as interaction of treatment by week and an interaction of baseline measurement by week.

Predefined subgroups: Efficacy in patients with detectable versus undetectable serum hCG, high versus low LH at baseline, low versus high BMI, low versus high BMD, low versus high fat %.

Ethics and side effects All patients will be informed of potential adverse effects, and that they can leave the trial at any point without any consequences. GnRH-analogs have been proven safe in numerous randomized clinical trials (RCT) and have for many years been involved in the treatment of several groups including children with precocious puberty, transgender hormone treatment, and as part of in vitro fertilization. MHT have been tested in previously large RCT, where an increased risk of breast cancer and thromboembolic events have been detected. It is estimated that the risk of breast cancer increases with 0.5 % after 5 years of hormonal treatment. It is therefore regarded safe for participant in this trial to be treated with estrogen in 8 weeks however women with increased risk of cancer or thromboembolic events will be excluded. All side effects will be closely monitored and reported. The study will be approved by the regional ethical committee, conducted in compliance with The Declaration of Helsinki, registered on clinicaltrial.gov, and monitored by the GCP unit of Copenhagen University Hospitals in compliance with International Conference on Harmonisation.