Comparative study on the effects of combined oral contraceptives and dienogest in women with endometriosis‑associated chronic pelvic pain

OBJECTIVE

To compare the effects of five combined oral contraceptives (COCs) - ethinylestradiol (EE) 30 μg/dienogest (DNG) 2 mg, EE 20 μg/drospirenone (DRSP) 3 mg, 17β-estradiol (E2) 1.5 mg/nomegestrol acetate (NomAc) 2.5 mg,estetrol (E4) 15 mg/DRSP 3 mg and estradiol valerate (E2V)/DNG - and DNG 2 mg daily in women with endometriosis-associated chronic pelvic pain (CPP), dysmenorrhea and dyspareunia.

STUDY DESIGN

This study was performed from October 2018 to March 2023. A database was set up to collect data from women in each of the six treatment groups. The level of endometriotic pain was measured using a visual analogue scale (VAS). Follow-up was performed at 3 and 6 months.

RESULTS

The intragroup analysis showed an improvement in the VAS score from baseline to 6-month follow-up for each group (p < 0.001). Intergroup analysis showed that women on COCs containing E2 or E4 had a greater improvement in CCP than women on COCs containing EE (at 3 months, p ≤ 0.001; at 6 months, p ≤ 0.009). Women on E4 15 mg/DRSP 3 mg showed a similar improvement to women on DNG at both 3- and 6-month follow-up, and greater improvement compared with women on COCs containing E2 at 6-month follow-up (p = 0.02). Greater improvement in dysmenorrhea and dyspareunia was seen in women on COCs containing E2 and E4, and DNG compared with women on COCs containing EE (p ≤ 0.001).

CONCLUSIONS

COCs containing E2 or E4 could be a better treatment for women with endometriosis-associated pain than COCs containing EE. They may represent a suitable alternative to the use of DNG, particularly for women who do not want to become pregnant.

Metabolism of progestogens used for contraception and menopausal hormone therapy

A variety of progestogens are widely used by women for contraception and menopausal hormone therapy. The progestogens undergo extensive metabolism by oral and parenteral routes of administration to form many metabolites. Although a small number of metabolites have been shown to be biologically active, most have not been tested for biologic activity. The present review shows that we know most about progesterone metabolism, followed by the metabolism of levonorgestrel and norethindrone. Very few studies have been carried out on metabolism of most of the progestogens. The clinical significance of this deficiency is that those progestogen metabolites that bind to the progesterone receptors may also bind to other steroid receptors and be responsible for some of the well-documented side effects of administered progestogens. We also discuss how obesity and genetic polymorphisms alter progestogen metabolism, and how development of oral progestogen formulations that are targeted to the colon, where the concentration of steroid-metabolizing enzymes is much lower than in the proximal gut, may have a beneficial effect on progestogen metabolism.

Prolonged use of nomegestrol acetate and risk of intracranial meningioma: a population-based cohort study

Background

Nomegestrol acetate (NOMAC) is a synthetic potent progestogen. This study aimed to assess the risk of intracranial meningioma associated with the prolonged use of NOMAC.

Methods

Observational cohort study using SNDS data (France). Women included had ≥ one dispensing of NOMAC between 2007 and 2017 (no dispensing in 2006). Exposure was defined as a cumulative dose >150 mg NOMAC within six months after first dispensing. A control group of women (cumulative dose ≤150 mg) was assembled. The outcome was surgery (resection or decompression) or radiotherapy for one or more intracranial meningioma(s). Poisson models assessed the relative risk (RR) of meningioma.

Findings

In total, 1,060,779 women were included in the cohort (535,115 in the exposed group and 525,664 in the control group). The incidence of meningioma in the two groups was 19.3 and 7.0 per 100,000 person-years, respectively (age-adjusted RRa = 2.9 [2.4-3.7]). The RRa for a cumulative dose of more than 6 g NOMAC was 12.0 [9.9-16.0]. In the event of treatment discontinuation for at least one year, the risk of meningioma was identical to that in the control group (RRa = 1.0 [0.8-1.3]). The location of meningiomas in the anterior and middle part of the skull base was more frequent with exposure to NOMAC.

Interpretation

We observed a strong dose-dependent association between prolonged use of NOMAC and the risk of intracranial meningiomas. These results are comparable to those obtained for cyproterone acetate, although the magnitude of the risk is lower. It is now recommended to stop using NOMAC if a meningioma is diagnosed.

Funding

The French National Health Insurance Fund (Cnam) and the French National Agency for Medicines and Health Products Safety (ANSM) via the Health Product Epidemiology Scientific Interest Group EPI-PHARE.

A review of the pharmacology, clinical outcomes, and real-world effectiveness, safety, and non-contraceptive effects of NOMAC/E2

Selecting an appropriate oral contraceptive can be challenging for healthcare professionals due to the abundance of marketed contraceptive options with different clinical and real-world effectiveness and safety profiles. Nomegestrol acetate + 17β-estradiol (NOMAC/E2) is a combined oral contraceptive (COC) that inhibits ovulation by suppressing ovarian function by a 17-hydroxy-progesterone derivative and an estrogen identical to that endogenously produced by the ovaries. This narrative review examines clinical and real-world studies of NOMAC/E2 based on a background literature search using PubMed and Google Scholar. The review outlines the pharmacology of NOMAC/E2, including its progestational activity, pharmacokinetics, and effects on carbohydrate metabolism, lipid metabolism, and coagulation parameters, and summarizes key clinical efficacy and safety data that led to the approval of NOMAC/E2 in Europe, Brazil, and Australia. To help elucidate how NOMAC/E2 clinical trial data translate into a real-world setting, this review describes the effectiveness and safety of NOMAC/E2 in prospective studies that include over 90,000 users (half of whom received NOMAC/E2), outlining its effects on risk of thrombosis, menstrual bleeding patterns, weight, mood, acne, bone health, and patient quality of life. Non-contraceptive benefits of NOMAC/E2 for women with endometriosis, dysmenorrhea, or pre-menstrual dysphoric disorder are also discussed. These data demonstrate that NOMAC/E2 has a long half-life and rapid absorption, is effective at preventing unwanted pregnancies, and exhibits a favorable safety profile in both clinical trials and real-world settings. Importantly, NOMAC/E2 is not associated with increased risk of venous thromboembolism, a major safety concern of healthcare professionals for women receiving hormonal contraceptives. This review highlights NOMAC/E2 as a differentiated option among COCs and could help inform oral contraceptive choice to ultimately improve patient management and outcomes in real-world settings.

Oral hormonal therapy as treatment option for abnormal uterine bleeding

BACKGROUND

abnormal uterine bleeding is a very frequent reason for referral to gynaecologists and can deeply influence the quality of life. Once organic causes requiring surgical treatment are ruled out, clinicians should be able to manage these patients conservatively in the most effective way.

MATERIALS AND METHODS

a search in PubMed/MEDLINE database was conducted in order to find relevant and recent meaningful sources for this narrative review.

RESULTS

LNG-IUS 52 mg is the first-line treatment for non-organic causes. Nevertheless, it could be contraindicated or declined by the patient. Combined oral contraceptives (COC) and progestin-only pills inhibit the hypothalamic-pituitary-ovarian axis, preventing ovulation, and induce endometrial atrophy. Consequently, they are effective in treating AUB. Moreover, brand new pills containing a combination of oestrogens, progestins and GnRH antagonists are now available for the management of AUB related to uterine fibroids.

CONCLUSIONS

In daily clinical practice, oral hormonal therapies are convenient and reversible tools to manage AUB when LNG-IUS 52 mg is contraindicated or turn down by the patient. Many oral hormonal therapies are prescribed to treat AUB, but only a few have been approved with this specific indication, therefore further large well-designed studies are necessary in order to compare the efficacy of different pills for treating AUB.

Progesterone and contraceptive progestin actions on the brain: A systematic review of animal studies and comparison to human neuroimaging studies

In this review we systematically summarize the effects of progesterone and synthetic progestins on neurogenesis, synaptogenesis, myelination and six neurotransmitter systems. Several parallels between progesterone and older generation progestin actions emerged, suggesting actions via progesterone receptors. However, existing results suggest a general lack of knowledge regarding the effects of currently used progestins in hormonal contraception regarding these cellular and molecular brain parameters. Human neuroimaging studies were reviewed with a focus on randomized placebo-controlled trials and cross-sectional studies controlling for progestin type. The prefrontal cortex, amygdala, salience network and hippocampus were identified as regions of interest for future preclinical studies. This review proposes a series of experiments to elucidate the cellular and molecular actions of contraceptive progestins in these areas and link these actions to behavioral markers of emotional and cognitive functioning. Emotional effects of contraceptive progestins appear to be related to 1) alterations in the serotonergic system, 2) direct/indirect modulations of inhibitory GABA-ergic signalling via effects on the allopregnanolone content of the brain, which differ between androgenic and anti-androgenic progestins. Cognitive effects of combined oral contraceptives appear to depend on the ethinylestradiol dose.

Randomized study on the effectiveness of nomegestrol acetate plus 17β-estradiol oral contraceptive versus dienogest oral pill in women with suspected endometriosis‑associated chronic pelvic pain

BACKGROUND

To evaluate the effects of a combined oral contraceptive containing 1.5 mg 17b-estradiol (E2) and 2.5 mg nomegestrol acetate (NOMAC) or 2 mg/daily dienogest (DNG) oral progestin on endometriosis-associated chronic pelvic pain (CPP) and on the quality of life (QoL) and sexual function, by a randomized study design.

METHODS

The E2/NOMAC group and DNG group included 99 and 98 women, respectively. The levels of CPP were measured by the visual analogic scale (VAS). The QoL scores were investigated by the Short Form-36 questionnaire (SF-36). Finally, sexual function was studied using the Female Sexual Function Index (FSFI), while sexual distress was studied by the Female Sexual Distress Scale (FSDS). The study had 3, 6 and 12-month follow-ups.

RESULTS

The intra-group analysis showed an improvement of the VAS score from baseline to the 12-month follow-up in the women of both groups (p < 0.001). The inter-group comparison showed a similar improvement of CPP (p = 0.06). Women on DNG had better SF-36 somatic (p < 0.01) and FSFI scores (p < 0.006) than women on E2/NOMAC at the 6- and 12-month follow-ups.

CONCLUSIONS

The results support the efficacy of both hormonal treatments, even if DNG was more effective than E2/NOMAC in a limited intergroup comparison.

Estradiol/nomegestrol acetate as a first-line and rescue therapy for the treatment of ovarian and deep infiltrating endometriosis

PURPOSE

Estradiol valerate/nomegestrol acetate (E2V/NOMAC) is a new combined oral contraceptive with a good tolerability profile and low drop-out rates, which was shown to improve menstrual-related symptoms. This study aims to evaluate its effectiveness in the control of symptoms and progression of disease in women with ovarian endomestriomas and deep infiltrating endometriosis (DIE).

METHODS

This was a retrospective cohort study on 39 women with pelvic endometriosis treated with E2V/NOMAC. We assessed for each patient, at the beginning of treatment and after 6 months, the painful symptoms, through a global VAS (Visual Analogue Scale) index and the size of the greatest ovarian and/or deep infiltrating endometriotic lesions.

RESULTS

After 6 months of treatment, a significant reduction was observed for the global VAS score for pain symptoms and for the mean size of ovarian endometriomas, whereas DIE lesions did not present significant changes in mean size.

CONCLUSIONS

E2/NOMAC was effective in reducing pain symptoms associated with pelvic endometriosis and the size of ovarian endometriomas, whereas DIE lesions remained stable. This therapy could provide good results in the control of symptoms and disease progression in women with pelvic endometriosis.

Clinical pharmacology of progestins

INTRODUCTION

In this paper, we report general pharmacological profile and major biological activities of natural progesterone (P) and progestins. The aim of this article consists of synthesizing the principal aspects of pharmacology and metabolism of P and progestins related to the clinical consequences of their use.

METHODS

We review scientific literature on the topic "Progestins", evaluating the most relevant data from original articles, reviews and meta-analyses.

EVIDENCE SYNTHESIS

Progestins represent a specific class of synthetic analogues of P clinically employed (alone or associated with estrogens) to manage several gynaecological conditions, for instance multiple abortions, luteal phase defect, premenstrual syndrome, abnormal uterine bleeding, endometriosis and menopause (for hormone replacement therapy). Besides their use in the field of contraception, many non-contraceptive benefits of estroprogestins are mostly due to the activities of progestins. Pharmacological characteristics, dosage and individual metabolism could be listed among the principal aspects influencing their clinical effects.

CONCLUSIONS

The choice of each progestin according to its pharmacological profile is crucial for the appropriate management of any gynaecological condition. An aware knowledge of these compounds is fundamental to hone medical practice.

Does Nomegestrol Acetate Plus 17β-Estradiol Oral Contraceptive Improve Endometriosis-Associated Chronic Pelvic Pain in Women?

Background: To evaluate the effects of a 24/4 regimen combined oral contraceptive (COC) containing 1.5 mg 17β-estradiol (E2) and 2.5 mg nomegestrol acetate (NOMAC) compared to on-demand nonsteroidal anti-inflammatory drugs (NSAIDs) on women affected by endometriosis-associated chronic pelvic pain (the primary end point) and their quality of life (QoL) and sexual function (the secondary end points).

Materials and Methods: Ninety-nine women on E2/NOMAC constituted the study group; and 63 women on NSAIDs constituted the control group. The visual analogic scale was used to measure the levels of pelvic pain, dysmenorrhea, and dyspareunia. To assess their QoL, sexual function, and sexual distress, the Short Form-36 (SF-36), the Female Sexual Function Index (FSFI), and the Female Sexual Distress Scale (FSDS) were used, respectively. The study included two follow-ups at 3 and 6 months.

Results: Improvement in chronic pelvic pain was observed in the study group at both the 3- and 6-month follow-ups (p < 0.001). SF-36, FSFI, and FSDS had a similar trend at the 3- and 6-month follow-ups (p < 0.001). Women on NSAIDs did not report any reduction in pain symptoms or improvement in QoL (p ≤ 0.4). However, they had a limited improvement of their FSFI and FSDS (p < 0.001). The improvement of the pain symptoms, QoL, FSFI, and FSDS, was more evident in women on E2/NOMAC than in those on NSAIDs, when the study group and control group values were compared at the 3- and 6-month follow-ups (p < 0.001).

Conclusions: Women on E2/NOMAC COC showed a better reduction of endometriosis-associated chronic pelvic pain and an improvement of their QoL and sexual activity than those of the women on NSAIDs.

Spontaneous regression of meningiomas after interruption of nomegestrol acetate: a series of three patients

BACKGROUND

The relationship between increased meningioma incidence and growth and long-term hormonal therapy with cyproterone acetate (CPA) in women has been recently established in literature. Following the raise in awareness from hormonal treatment, we describe a potential relationship between the progesterone agonist nomegestrol acetate (NOMAC) and meningioma growth.

METHODS

After implementation of a screening protocol to detect potential interactions between hormonal exposure and occurrence of meningioma, we identified patients taking NOMAC and newly diagnosed with a meningioma. NOMAC was stopped and those patients were followed tightly both clinically and radiologically. Retrospective volumetric analysis of the tumors was performed on the imaging.

RESULTS

Three patients were identified for the study. After cessation of the NOMAC, tumor shrinkage was documented for all meningiomas within the first month. Up to 70% of tumor volume reduction was observed during the first year of follow-up in one of them. None of the patients developed new symptoms.

CONCLUSION

We report the first cases of meningiomas responsiveness to discontinuation of hormonal therapy with NOMAC. Similarly to cases associated with long-term CPA intake, tumor reduction, and improvement of clinical symptoms can be observed after cessation of NOMAC.

Combined hormonal influence of cyproterone acetate and nomegestrol acetate on meningioma: a case report

Cyproterone acetate (CPA) is an antiandrogenic drug which has recently been recognized to promote the occurrence and growth of intracranial meningiomas. Nomegestrol acetate (NOMAC) is a widely used progestin-like drug that could be suggested as an alternative for patients taking CPA. We report a case of CPA-related meningioma for which relay from CPA to NOMAC led to further tumor growth and cessation of NOMAC-induced tumor shrinkage. We suggest NOMAC can have a similar effect than CPA on meningiomas. The use of NOMAC as replacement for CPA in the presence of a meningioma should be discouraged until further evidence becomes available on the role of NOMAC in such instances.

Isolation, synthesis, and cytotoxicity evaluation of two impurities in nomegestrol acetate

Nomegestrol acetate (NOMAc) is a synthetic progesterone analog and classified as a fourth-generation progestin. It has been approved in many countries for oral contraception, hormonal replacement therapy (HRT), and treatment of various gynecological disorders. There are several synthetic routes reported for the synthesis of NOMAc and they all share the very similar last three to five steps toward the conversion of 6-methylene to 6-methyl-6,7-unsaturated structure. Therefore the final product from different processing routes may have similar impurity profiles. In the analysis of NOMAc, we identified two impurities, impurity A (listed in EP 8.0) and impurity B (not specified in EP 8.0). Both impurities were further confirmed by synthesis. In addition, both impurities and NOMAc were evaluated for their in vitro cytotoxicities against L02 liver cells, mesenchymal stem cells, MCF-7 breast cancer cells, and C33A cervical cancer cells. These three analogs are not cytotoxic to the four cell lines at low concentrations (<20 μM). NOMAc and impurity A showed cytotoxicity to L02, MCF-7, and C33A cells at high concentrations, while impurity B did not show significant cytotoxicity to any of the cell lines tested.

Steroid Hormones and Their Action in Women's Brains: The Importance of Hormonal Balance

Sex hormones significantly impact women's lives. Throughout the different stages of life, from menarche to menopause and all stages in between, women experience dramatic fluctuations in the levels of progesterone and estradiol, among other hormones. These fluctuations affect the body as a whole, including the central nervous system (CNS). In the CNS, sex hormones act via steroid receptors. They also have an effect on different neurotransmitters such as GABA, serotonin, dopamine, and glutamate. Additionally, studies show that sex hormones and their metabolites influence brain areas that regulate mood, behavior, and cognitive abilities. This review emphasizes the benefits a proper hormonal balance during the different stages of life has in the CNS. To achieve this goal, it is essential that hormone levels are evaluated considering a woman's age and ovulatory status, so that a correct diagnosis and treatment can be made. Knowledge of steroid hormone activity in the brain will give women and health providers an important tool for improving their health and well-being.

Biphasic modulation of cAMP levels by the contraceptive nomegestrol acetate. Impact on P-glycoprotein expression and activity in hepatic cells

ABC transporters are key players in drug excretion with alterations in their expression and activity by therapeutic agents potentially leading to drug-drug interactions. The interaction potential of nomegestrol acetate (NMGA), a synthetic progestogen increasingly used as oral contraceptive, had never been explored. In this work we evaluated (1) the effect of NMGA on ABC transporters in the human hepatic cell line HepG2 and (2) the underlying molecular mechanism. NMGA (5, 50 and 500 nM) increased P-glycoprotein (P-gp) expression at both protein and mRNA levels and reduced intracellular calcein accumulation, indicating an increase also in transporter activity. This up-regulation of P-gp was corroborated in Huh7 cells and was independent of the classical progesterone receptor. Instead, using a siRNA-mediated silencing approach, we demonstrated the involvement of membrane progesterone receptor α. Moreover, we found that the activation of this receptor by NMGA led to a falling-rising profile in intracellular cAMP levels and protein kinase A activity over time, ultimately leading to transcriptional P-gp up-regulation. Finally, we identified inhibitory G protein and phosphodiesterases as mediators of this novel biphasic modulation. These results demonstrate the ability of NMGA to selectively up-regulate hepatic P-gp expression and activity and constitute the first report of ABC transporter modulation by membrane progesterone receptor α. If a similar regulation took place in vivo, decreased bioavailability and therapeutic efficacy of NMGA-coadministered P-gp substrates could be expected. This holds special importance considering long-term administration of NMGA and broad substrate specificity of P-gp.

Body composition and psychological improvement in healthy premenopausal women assuming the oral contraceptive containing micronized estradiol (E2) and nomegestrol acetate (NOMAC)

This observational study was conducted in healthy premenopausal women, who presented themselves for contraceptive advice at the outpatient Family Planning Clinics of the Department of Obstetrics and Gynecology of the University of Cagliari, Hospital-University of Cagliari (Italy). After a screening period of three menstrual cycles, 48 women without contraindications to estroprogestin contraceptives (OCs) were included in the study. The primary purposes of the study were to evaluate whether a 12-month-treatment with the combined OC containing micronized estradiol (1.5 mg, E2) plus nomegestrol acetate (2.5 mg, NOMAC) (E2/NOMAC) interfere on anthropometric indices (AI), body composition (BC) and psychological status (PS). In subjects with dysmenorrhea (#36), its intensity was evaluated using the visuo analogic scale (VAS), both before and during the 12-month-treatment with E2/NOMAC. E2/NOMAC did not modify neither AI nor BC in the 40 subjects who concluded the study. The PS and the VAS of dysmenorrhea were significantly (p < 0.0001) improved from the first cycle of treatment and throughout the E2/NOMAC treatment in comparison with basal values. The study suggests that E2/NOMAC is devoid of negative effects on AI and BC, with additional benefits on PS and dysmenorrhea.

The other side of progestins: effects in the brain

Progestins are a broad class of progestational agents widely differing in their chemical structures and pharmacological properties. Despite emerging data suggest that progestins, besides their action as endometrial protection, can also have multiple nonreproductive functions, much remains to be discovered regarding the actions exerted by these molecules in the nervous system. Here, we report the role exerted by different progestins, currently used for contraception or in postmenopausal hormone replacement therapies, in regulating cognitive functions as well as social behavior and mood. We provide evidence that the effects and mechanisms underlying their actions are still confusing due to the use of different estrogens and progestins as well as different doses, duration of exposure, route of administration, baseline hormonal status and age of treated women. We also discuss the emerging issue concerning the relevant increase of these substances in the environment, able to deeply affect aquatic wildlife as well as to exert a possible influence in humans, which may be exposed to these compounds via contaminated drinking water and seafood. Finally, we report literature data showing the neurobiological action of progestins and in particular their importance during neurodegenerative events. This is extremely interesting, since some of the progestins currently used in clinical practice exert neuroprotective and anti-inflammatory effects in the nervous system, opening new promising opportunities for the use of these molecules as therapeutic agents for trauma and neurodegenerative disorders.

An update on new orally administered contraceptives for women

INTRODUCTION

The focus in contraception is shifting from oral contraceptives to more effective methods, such as implants and intrauterine devices. Generics are favored by third-party payors. As a result, potentially exciting developments in branded pills to increase safety or to reduce side effects may have gone unnoticed.

AREAS COVERED

This article reviews the features of each of the four new oral contraceptives that have been introduced in the United States and/or Europe in the last few years. The motivation for the development of each product is outlined as is its efficacy, safety, tolerability and the noncontraceptive applications that have been explored are described.

EXPERT OPINION

The hypothesis that using estradiol in place of ethinyl estradiol would reduce the risk of venous thromboembolism is still to be proven. However, the stronger progestogens used in these formulations may offer other tangible benefits for selected women. The new products for extended cycle pill use may have less impact. The flexible regimen can be adopted using any pill, but the approved product does provide convenience to patients. Cost will continue to be the determining factor in the acceptance of these new products, unless substantial health benefits can be conclusively proven.

Nomegestrol acetate/17-beta estradiol: a review of efficacy, safety, and patient acceptability

Nomegestrol acetate (NOMAC) 2.5 mg with 17-beta estradiol (E2) 1.5 mg is a new combined oral contraceptive (COC) formulation and is the first monophasic E2 pill to be marketed, having been licensed for use in Europe in 2011. It is available to be taken daily in a regimen of 24 active pills followed by four placebo pills. NOMAC is a highly selective 19-nor progestogen derivative with specific binding to progesterone receptors, anti-estrogenic activity and no androgenic, mineralocorticoid nor glucocorticoid effects. E2 is an estrogen that is identical to endogenous estrogen. While it has been in use for only a short period of time, current evidence suggests that NOMAC/E2 is just as effective, safe, and acceptable as existing COC preparations. Two large Phase III trials conducted in the Americas and across Europe, Australia, and Asia showed lower cumulative pregnancy rates in the NOMAC/E2 groups compared to the drospirenone (DRSP) 3 mg in combination with ethinyl estradiol (EE) 30 µg (DRSP/EE) groups but this difference was not statistically significant. NOMAC/E2 exhibits a good safety profile and has less effects on cardiovascular risk, hemostatic, metabolic, and endocrine factors in comparison to COCs containing EE in combination with levonorgestrel (LNG) or DRSP. NOMAC/E2 has also been found to cause less breast cell proliferation when compared to E2 alone and has some anti-proliferative effect on human breast cancer cells. NOMAC/E2 is considered acceptable as its compliance, continuation rates, and bleeding patterns were similar to COCs containing DRSP/EE and LNG 150 µg combined with EE 30 µg or LNG 100 µg combined with EE 20 µg (LNG/EE). However, discontinuation was found to be slightly higher in the NOMAC/E2 groups in the two large Phase III trials comparing NOMAC/E2 use with DRSP/EE. As the scientific literature has limited information on NOMAC/E2, further experience with NOMAC/E2 is required.

Toward a new concept of "natural balance" in oral estroprogestin contraception

The Pill has undergone many changes since its first appearance some 50 years ago. Key developments included the reduction of ethinylestradiol doses and the synthesis of new progestins in order to increase safety, compliance and efficiency. Low-dose combined oral contraceptives (COCs) are currently the preferred option for millions of women. Due to this widespread use, it has been argued that the safety of COCs should be even better, raising the threshold for excellence. Yet in spite of major improvements, there is still an associated risk of venous thromboembolism (VTE). The next step in COCs' evolution should take total estrogenicity and hepatic estro-androgenic balance into account. The focus on the estrogen component--which has not changed in 50 years--has yielded a new class of natural estrogen pills. Following the introduction of a first quadriphasic pill, a monophasic estradiol pill based on the concept of "natural balance" was subsequently made available. These recent achievements could represent a step forward in the evolution of COCs and pave the way for better safety.

Nomegestrol acetate-17b-estradiol for oral contraception

Oral contraceptives remain a popular method of contraception over 50 years after their introduction. While safe and effective for many women, the failure rate of oral contraception is about 8%. Concerns about the risk of venous thromboembolism continue to drive the search for the safest oral contraceptive formulations. The oral contraceptive NOMAC-E2 contains nomegestrol acetate (NOMAC) 2.5 mg + 17b-estradiol (E2) 1.5 mg. The approved dosing regimen is 24 days of active hormone, followed by a 4-day hormone-free interval. NOMAC is a progestin derived from testosterone, which has high bioavailability, rapid absorption, and a long half-life. Estradiol, though it has a lower bioavailability, has been successfully combined with NOMAC in a monophasic oral contraceptive. Two recently published randomized controlled trials demonstrate that NOMAC-E2 is an effective contraceptive, with a Pearl Index less than one pregnancy per 100 woman-years. The bleeding pattern on NOMAC-E2 is characterized by fewer bleeding/spotting days, shorter withdrawal bleeds, and a higher incidence of amenorrhea than the comparator oral contraceptive containing drospirenone and ethinyl estradiol. The adverse event profile appears to be acceptable. Few severe adverse events were reported in the randomized controlled trials. The most common adverse events were irregular bleeding, acne, and weight gain. Preliminary studies suggest that NOMAC-E2 does not seem to have negative effects on hemostatic and metabolic parameters. While no one oral contraceptive formulation is likely to be the optimum choice for all women, NOMAC-E2 is a formulation with effectiveness comparable with that of other oral contraceptives, and a reassuring safety profile.

Progestogens used in postmenopausal hormone therapy: differences in their pharmacological properties, intracellular actions, and clinical effects

The safety of progestogens as a class has come under increased scrutiny after the publication of data from the Women's Health Initiative trial, particularly with respect to breast cancer and cardiovascular disease risk, despite the fact that only one progestogen, medroxyprogesterone acetate, was used in this study. Inconsistency in nomenclature has also caused confusion between synthetic progestogens, defined here by the term progestin, and natural progesterone. Although all progestogens by definition have progestational activity, they also have a divergent range of other properties that can translate to very different clinical effects. Endometrial protection is the primary reason for prescribing a progestogen concomitantly with postmenopausal estrogen therapy in women with a uterus, but several progestogens are known to have a range of other potentially beneficial effects, for example on the nervous and cardiovascular systems. Because women remain suspicious of the progestogen component of postmenopausal hormone therapy in the light of the Women's Health Initiative trial, practitioners should not ignore the potential benefits to their patients of some progestogens by considering them to be a single pharmacological class. There is a lack of understanding of the differences between progestins and progesterone and between individual progestins differing in their effects on the cardiovascular and nervous systems, the breast, and bone. This review elucidates the differences between the substantial number of individual progestogens employed in postmenopausal hormone therapy, including both progestins and progesterone. We conclude that these differences in chemical structure, metabolism, pharmacokinetics, affinity, potency, and efficacy via steroid receptors, intracellular action, and biological and clinical effects confirm the absence of a class effect of progestogens.

A New Contraceptive Pill Containing 17β-Estradiol and Nomegestrol Acetate

Most combined oral contraceptive pills contain ethinyl estradiol (EE) with progestins. In order to minimize the pill's cardiovascular risks, the concept of using 17β-estradiol (E2), the endogenous estradiol, arose in the 1970s. Many attempts to develop a pill containing 17β-E2 have failed as cycle control was low. The first pill containing 17β-E2 was launched in 2011. This monophasic pill contains 24 pills with 1.5 mg 17β-E2 and 2.5 mg nomegestrol acetate, and four placebo pills. Studies conducted in Europe and the USA demonstrate that its Pearl index is 0.38 and 1.13, respectively. It has less influence on hemostasis, fibrinolysis markers, lipids and carbohydrate metabolism than the combined oral contraceptive levonorgestrel/EE (150 g/30 g and 100 μg/20 μg). Withdrawal bleedings are shorter and lighter as compared with women using drospirenone/EE (3 mg/30 μg). The number of women without withdrawal bleeding is approximately 30% after 12 months. Even though its contraindications are identical to other combined oral contraceptives, this nomegestrol acetate/E2 pill should be considered to be of interest for many women.

Preclinical pharmacological profile of nomegestrol acetate, a synthetic 19-nor-progesterone derivative

BACKGROUND

Nomegestrol acetate (NOMAC), a synthetic progestogen derived from 19-nor-progesterone, recently completed clinical trials for use with 17beta-estradiol in a new monophasic combined oral contraceptive. In this review, published as well as previously unpublished preclinical studies that detail the effects of NOMAC on estrogenic, progestogenic, and androgenic systems, as well as mineralocorticoid, glucocorticoid, bone, and metabolic indices are described.

METHODS

In vitro assays to determine NOMAC structure-activity relationships used tissue derived from rat uteri. Transactivation profiles were performed using Chinese hamster ovary (CHO) cells transfected with cDNAs encoding human steroid receptors. Estrogenic and anti-estrogenic activities were monitored in vivo in rats as well as in vitro in human breast cancer cells. Standard in vivo techniques were used in rats to determine progestational activity; antigonadotropic, androgenic, mineralocorticoid, and glucocorticoid activities; as well as effects on bone and other metabolic indices. Ovulation inhibition was monitored in rats and primates. NOMAC's effects on cardiovascular systems were determined in dogs and primates.

RESULTS

NOMAC was without significant agonistic or antagonistic activity for estrogen receptor alpha or beta in vitro, and inhibited ovulation in rats and monkeys (2.5 mg/kg and 1 mg/kg, respectively). NOMAC lacked androgenic, antimineralocorticoid, glucocorticoid, and metabolic activity and exhibited moderate anti-androgenic activity in rats. NOMAC did not affect bone mineral density (BMD) in rats or hemodynamic and electrophysiologic parameters in dogs and primates.

CONCLUSIONS

NOMAC is a selective progestogen structurally similar to progesterone that has modest anti-androgenic activity and does not affect lipid or carbohydrate metabolism, BMD, or many cardiovascular parameters in selected animal models.

Pharmacokinetic profile of nomegestrol acetate and 17β-estradiol after multiple and single dosing in healthy women

BACKGROUND

The pharmacokinetics of the monophasic oral contraceptive nomegestrol acetate (NOMAC) plus 17β-estradiol (E(2)) were investigated after a single dose and multiple dosing.

STUDY DESIGN

NOMAC/E2 (2.5 mg/1.5 mg) was administered daily to healthy women (18-50 years, n=23) for 24 days; blood samples for pharmacokinetic analysis were obtained on Day 24 and again, after a 10-day pill-free interval, on Day 35 after a single dose.

RESULTS

NOMAC reached steady state after 5 days with mean ±standard deviation (SD) trough NOMAC concentration (C(av)) of 4.4±1.4 ng/mL. On Day 24, mean±SD peak NOMAC concentration (Cmax, 12.3±3.5 ng/mL) was reached in mean 1.5 h (t(max)); the mean±SD elimination half-life (t(½)) was 45.9±15.3 h. After a single dose, NOMAC mean±SD C(max) was 7.2±2.0 ng/mL and mean±SD t(½) was 41.9±16.2 h. On Day 24, E2 mean±SD C(av) was 50.3±25.7 pg/mL; mean±SD Cmax was 86.0±51.3 pg/mL. After a single dose, mean±SD E2 Cmax was 253±179 pg/mL.

CONCLUSIONS

These data demonstrate that NOMAC/E2 has a pharmacokinetic profile consistent with once-daily dosing.

Contraceptives with novel benefits

INTRODUCTION

Progesterone receptor (PR) agonists (progestins) and antagonists are developed for female contraceptives. However, non-contraceptive applications of newer progestins and PR modulators are being given more attention.

AREAS COVERED

The newer PR agonists including drospirenone, nomegestrol, trimegestone, dienogest and nestorone are being evaluated as contraceptives with health benefits because of their unique pharmacological properties. The selective PR modulators (SPRM; PR antagonists with PR agonistic properties) are under development not only for emergency contraception but also for other health benefits such as the treatment of endometritis and leiomyoma. After searching the literature from PubMed, clinicaltrials.gov and patent database, this review focuses on the effects and mechanisms of these progestins, and SPRMs as contraceptives with other health benefits.

EXPERT OPINION

PR agonists and antagonists that have novel properties may generate better contraceptive effects with other health benefits.

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol compared with one containing levonorgestrel and ethinylestradiol on haemostasis, lipids and carbohydrate metabolism

OBJECTIVES

To compare the effects of a combined oral contraceptive (COC) containing nomegestrol acetate and 17β-oestradiol (NOMAC/E2) on haemostasis, lipids, carbohydrate metabolism, C-reactive protein (CRP) and sex hormone-binding globulin (SHBG) with those of a COC containing levonorgestrel and ethinylestradiol (LNG/EE).

METHODS

In a randomised, open-label study, 121 healthy women, 18-50 years of age, were randomly assigned to receive NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n=60) or LNG/EE (150 μg/30 μg) in a 21/7-day regimen (n=61) for six cycles. The primary outcome was the change from baseline to cycle 6 for all indices.

RESULTS

All parameters were similar at baseline between the two groups. Over six cycles, NOMAC/E2 had less effect on most haemostatic indices than LNG/EE. Lipids were essentially unchanged with NOMAC/E2, whereas with LNG/EE high-density lipoprotein cholesterol decreased and low-density lipoprotein cholesterol and triglycerides slightly increased. NOMAC/E2 induced negligible changes in glucose and insulin parameters, in contrast to LNG/EE. A much smaller increase in CRP was observed with NOMAC/E2 than with LNG/EE. NOMAC/E2 was associated with a greater increase in SHBG.

CONCLUSIONS

The monophasic COC NOMAC/E2 had less influence on haemostasis, lipids and carbohydrate metabolism than the COC LNG/EE.

Efficacy and tolerability of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol in a 24/4 regimen, in comparison to an oral contraceptive containing ethinylestradiol and drospirenone in a 21/7 regimen

OBJECTIVES

The primary objective was to assess the efficacy, cycle control and tolerability of a monophasic combined oral contraceptive (COC) containing nomegestrol acetate (NOMAC) and 17β-oestradiol (E2). Effects on acne were evaluated as a secondary objective. Results were compared to those of a COC containing drospirenone (DRSP) and ethinylestradiol (EE).

METHODS

Women (aged 18-50 years) were randomised to receive NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n=1591) or DRSP/EE (3 mg/30 μg) in a 21/7-day regimen (n=535) for 13 cycles.

RESULTS

Estimated Pearl Indices for NOMAC/E2 and DRSP/EE were 0.38 and 0.81 in women aged≤35 years and 0.31 and 0.66 for all women (18-50 years), respectively. Scheduled withdrawal bleedings were shorter and lighter among users of NOMAC/E2 and were sometimes absent altogether. Intracyclic bleeding/spotting was infrequent in both groups, and decreased over time. Type and frequency of adverse events were similar to those typically reported for COCs.

CONCLUSIONS

These data show that NOMAC/E2 provides high contraceptive efficacy with acceptable cycle control as well as an overall adverse event profile similar to that of DRSP/EE.

The future of contraception: innovations in contraceptive agents: tomorrow's hormonal contraceptive agents and their clinical implications

Currently available contraceptive methods have not eliminated the burden of unintended pregnancy. Future progress will require technological advancements, leading to the development of novel and highly effective birth control strategies that will be acceptable to the general population. Included are highlights of some of the ongoing research, demonstrating the development of methods with the potential to be highly effective, widely accepted, easy to use, and more cost-effective, with fewer side effects, than currently available options.

Effects of a monophasic combined oral contraceptive containing nomegestrol acetate and 17β-oestradiol in comparison to one containing levonorgestrel and ethinylestradiol on markers of endocrine function

Objectives

To compare the effects of two monophasic combined oral contraceptives, containing either nomegestrol acetate/17β-oestradiol (NOMAC/E2) or levonorgestrel/ ethinylestradiol (LNG/EE) on endocrine function, androgens, and sex hormone-binding globulin (SHBG).

Methods

Randomised, open-label, multi-centre trial involving 121 healthy women, aged 18-50 years old. Participants received NOMAC/E2 (2.5 mg/1.5 mg) in a 24/4-day regimen (n = 60) or LNG/EE (150 μg/30 μg) in a 21/7-day regimen (n = 61) for six cycles. The primary outcome was the change from baseline to cycle 6 in markers of adrenal and thyroid function, androgens, and SHBG.

Results

Total cortisol, corticosteroid-binding globulin (CBG), and thyroxine-binding globulin (TBG) increased from baseline in both groups, with significantly greater increases in the LNG/EE group. No relevant changes from baseline or differences between the groups were observed for thyroid-stimulating hormone (TSH) and free thyroxine (T₄). Androgens and androgen precursors decreased from baseline in both groups, with significantly greater decreases in the LNG/EE group (except for free testosterone). A greater increase in SHBG was observed with NOMAC/E2 than with LNG/EE.

Conclusions

NOMAC/E2 has significantly less influence on markers of adrenal and thyroid function and androgens than LNG/EE. The clinical relevance of these findings requires further study.

Tailoring combination oral contraceptives to the individual woman

BACKGROUND

Over the last 50 years, there has been intense interest in the type of progestin used in combined oral contraceptives (COC) in an attempt to exploit novel properties and minimize adverse events. At the same time, the dose of synthetic estrogen, ethinylestradiol, in COC pills has been reduced to minimize risks for ischemic stroke, myocardial infarction, and venous thromboembolism. New formulations, including extended-cycle or continuous-use COCs or those that use a natural estrogen, estradiol, may offer improvements over their predecessors.

METHODS

A Medline search was performed to encompass studies published since 1990 that pertain to the pharmacology of estrogens and progestins used in COCs, risks and adverse events associated with COCs, and extended or continuous-use COCs.

RESULTS

New progestins structurally related to progesterone and spironolactone may exhibit more selective binding to the progesterone receptor and lack androgenic adverse effects associated with progestins structurally related to testosterone. Recently, COCs containing natural (17β-estradiol) or conjugated estrogen (estradiol valerate) rather than ethinylestradiol have been developed in order to move to a more natural estrogen. Although many of the new progestins incorporated into COCs have not demonstrated the negative effects on lipid metabolism and other adverse events associated with the traditional progestins, the goal of attaining good cycle control has yet to be achieved. Extended-cycle and continuous-use regimens are now available that reduce the frequency of menses, but breakthrough bleeding remains a problem.

CONCLUSIONS

Appropriate counseling to raise awareness of the specific characteristics of the different COC options available may optimize adherence and patient acceptability.

Molecular mechanisms of steroid receptor-mediated actions by synthetic progestins used in HRT and contraception

Synthetic progestins are used by millions of women as contraceptives and in hormone replacement therapy (HRT), although their molecular mechanisms of action are not well understood. The importance of investigating these mechanisms, as compared to those of progesterone, has been highlighted by clinical evidence showing that medroxyprogesterone acetate (MPA), a first generation progestin, increases the risk of breast cancer and coronary heart disease in HRT users. A diverse range of later generation progestins with varying structures and pharmacological properties is available for therapeutic use and it is becoming clear that different progestins elicit beneficial and adverse effects to different extents. These differences in biological activity are likely to be due to many factors including variations in dose, metabolism, pharmacokinetics, bioavailability, and regulation of, and/or binding, to serum-binding proteins and steroidogenic enzymes. Since the intracellular effects on gene expression and cell signaling of steroids are mediated via intracellular steroid receptors, differential actions via the progesterone and other steroid receptors and their isoforms, are likely to be the major cause of differential intracellular actions of progestins. Since many progestins bind not only to the progesterone receptor, but also to the glucocorticoid, androgen, mineralocorticoid, and possibly the estrogen receptors, it is plausible that synthetic progestins exert therapeutic actions as well as side-effects via some of these receptors. Here we review the molecular mechanisms of intracellular actions of old (MPA, norethisterone, levonorgestrel, gestodene) vs. new (drospirenone, dienogest, trimegestone) generation progestins, via steroid receptors.

Nomegestrol acetate, a novel progestogen for oral contraception

Nomegestrol acetate (NOMAC) is a potent, highly selective progestogen, which is structurally similar to 19-norprogesterone and characterized as a full agonist at the progesterone receptor, with no or minimal binding to other steroid receptors, including the androgen and glucocorticoid receptors. In animal models, NOMAC demonstrated moderate antiandrogenic activity and strong antiestrogenic activity. In clinical studies, the progestogen was associated with effective suppression of gonadotropic activity and ovulation in premenopausal women, and a neutral impact on hemostasis, lipids, and carbohydrate metabolism. In normal and cancerous human breast tissue, NOMAC has shown favorable effects on estrogen metabolism, and in human breast cancer cell lines in vitro, it does not stimulate cell proliferation. The pharmacologic profile of NOMAC suggested that it would be well suited for combination with a physiologic estrogen in a combined oral contraceptive (COC), with the aim of achieving effective contraception with good cycle control and a favorable safety profile. A monophasic COC containing NOMAC 2.5mg and 17β-estradiol (E2) 1.5mg, administered in a 24/4-day regimen, is currently under clinical investigation. In a phase III study, NOMAC/E2 provided consistent and robust ovulation inhibition, with contraceptive effects that compared favorably with those of drospirenone 3mg/ethinyl estradiol (EE) 30 μg. Investigators for a second phase III study reported less overall impact with NOMAC/E2 on hemostatic, lipid, inflammatory, and carbohydrate metabolism parameters than with levonorgestrel 150 μg/EE 30 μg. These clinical findings are promising; however, full publication of results from the pivotal phase III trials of NOMAC/E2 is pending.