Estetrol-Drospirenone combination oral contraceptive: a clinical study of contraceptive efficacy, bleeding pattern and safety in Europe and Russia

Effects of E4/DRSP on self-reported physical and emotional premenstrual and menstrual symptoms: data from the phase 3 clinical trial in Europe and Russia

PURPOSE

To describe the effects of estetrol (E4) 15 mg/drospirenone (DRSP) 3 mg on physical and emotional premenstrual and menstrual symptoms.

MATERIALS AND METHODS

We used Menstrual Distress Questionnaire (MDQ) data from a phase-3 trial (NCT02817828) in Europe and Russia with participants (18 - 50 years) using E4/DRSP for up to 13 cycles. We assessed mean changes in MDQ-t-scores from baseline to end of treatment in premenstrual (4 days before most recent flow) and menstrual (most recent flow) scores for 4 MDQ domains in starters and switchers (use of hormonal contraception in prior 3 months) and performed a shift analysis on individual symptoms within each domain.

RESULTS

Of 1,553 treated participants, 1,398(90.0%), including 531(38%) starters, completed both MDQs. Starters reported improvements for premenstrual Pain (-1.4), Water Retention (-3.3) and Negative Affect (-2.5); and for menstrual Pain (-3.5), Water Retention (-3.4), and Negative Affect (-2.7) (all p < 0.01). For switchers, no changes were significant except an increase in premenstrual (+1.0, p = 0.02) and menstrual (+1.5, p = 0.003) Water Retention. We observed a change in symptom intensity in >40% of participants for Cramps, Backache and Fatigue (domain Pain), Painful or Tender Breast and Swelling (domain Water Retention) and Mood Swings and Irritability (domain Negative Affect).

CONCLUSION

E4/DRSP starters experienced significant improvements in the domains Pain, Water Retention and Negative Affect particularly benefiting those with more severe baseline symptoms. Switchers showed minimal changes.

Oestrogens in oral contraception: considerations for tailoring prescription to women's needs

BACKGROUND

The oestrogenic component of combined oral contraceptives (COCs) has changed over years with the aim of reducing oestrogen-related side effects and risks, whilst maintaining oestrogen beneficial effects, particularly on cycle control.

PURPOSE

To describe the pharmacological profiles of different oestrogens commonly used in COCs to provide insights on contraceptive prescription tailored to women's needs.

RESULTS

All COCs ensure a high contraceptive efficacy. COCs containing the natural oestrogens oestradiol (E2), oestradiol valerate (E2V) and estetrol (E4) have limited impact on liver metabolism, lipid and carbohydrate metabolism, haemostasis and sex hormone binding globulin levels, compared with ethinylestradiol (EE). COCs with E2 and E2V appear also to entail a lower elevation of the risk of venous thromboembolism vs. EE-containing pills. No epidemiological data are available for E4-COC. E2- and E2V-containing COCs seem to exert a less stabilising oestrogenic effect on the endometrium compared with EE-COCs. The E4-COC results in a predictable bleeding pattern with a high rate of scheduled bleeding and minimal unscheduled bleeding per cycle. Based on in vitro and in vivo animal data, E4 seems to be associated with a lower effect on cell breast proliferation.

CONCLUSION

Today various COCs contain different oestrogens. Prescribers must be familiar with the different properties of each oestrogen for a tailored contraceptive recommendation, considering their safety and contraceptive efficacy, as well as women's needs and preferences.

Combined oral contraceptive with estetrol plus drospirenone: from pharmacokinetics to clinical applications

INTRODUCTION

Drospirenone/estetrol (DRSP/E4) is a combined oral contraceptive (COC) recently approved in several countries. It is composed of 15 mg of E4, a natural estrogen produced by human fetal liver throughout pregnancy, and 3 mg of DRSP, the first synthetic progestin used in oral contraception derived from 17-α-spirolactone. E4 and DRSP synergistically prevent pregnancy by inhibiting ovulation. E4 differs from 17-β-estradiol or ethinylestradiol because it represents a native estrogen with selective action in tissues (NEST), therefore it displays both agonist and antagonist estrogenic effects in different tissues.

AREAS COVERED

In this paper, we reviewed the scientific literature published in English prior to April 2023 and gathered information on the pharmacodynamics and pharmacokinetics of DRSP, E4 and their combination for contraception. We also proposed possible clinical applications based on the characteristics of the components of this COC.

EXPERT OPINION

E4/DRSP-based COC has shown high tolerability, safety and satisfaction and may represent a viable choice in young girls in need of oral contraception and pill users who suffer from high cholesterol, breast tenderness or water retention. Moreover, this new COC shows higher scheduled bleeding rate compared to other pills containing natural estrogens. All the data are reassuring, permitting long-term use.

Nanomaterials Solutions for Contraception: Concerns, Advances, and Prospects

Preventing unintentional pregnancy is one of the goals of a global public health policy to minimize effects on individuals, families, and society. Various contraceptive formulations with high effectiveness and acceptance, including intrauterine devices, hormonal patches for females, and condoms and vasectomy for males, have been developed and adopted over the last decades. However, distinct breakthroughs of contraceptive techniques have not yet been achieved, while the associated long-term adverse effects are insurmountable, such as endocrine system disorder along with hormone administration, invasive ligation, and slowly restored fertility after removal of intrauterine devices. Spurred by developments of nanomaterials and bionanotechnologies, advanced contraceptives could be fulfilled via nanomaterial solutions with much safer and more controllable and effective approaches to meet various and specific needs for women and men at different reproductive stages. Nanomedicine techniques have been extended to develop contraceptive methods, such as the targeted drug delivery and controlled release of hormone using nanocarriers for females and physical stimulation assisted vasectomy using functional nanomaterials via photothermal treatment or magnetic hyperthermia for males. Nanomaterial solutions for advanced contraceptives offer significantly improved biosafety, noninvasive administration, and controllable reversibility. This review summarizes the nanomaterial solutions to female and male contraceptives including the working mechanisms, clinical concerns, and their merits and demerits. This work also reviewed the nanomaterials that have been adopted in contraceptive applications. In addition, we further discuss safety considerations and future perspectives of nanomaterials in nanostrategy development for next-generation contraceptives. We expect that nanomaterials would potentially replace conventional materials for contraception in the near future.

The benefits of estetrol addition to drospirenone for contraception

Ethinylestradiol and drospirenone combined oral contraceptive formulations have been marketed for >20 years. Drospirenone has antimineralocorticoid and anti-androgenic effects that may offer several health benefits. Recently, 2 new drospirenone-containing oral contraceptives entered the market, 1 as a progestin-only pill containing 4 mg drospirenone and the other as a combined oral contraceptive containing 15 mg estetrol and 3 mg drospirenone. Estetrol has a unique differential effect on nuclear and membrane estrogen α-receptors when compared with other estrogens, leading to low impact on the liver, breast, and hemostasis parameters and a beneficial effect on the endometrium, vagina, cardiovascular system, bone, and brain. Phase 3 clinical studies demonstrated that the Pearl Index (pregnancies per 100-woman-years) for drospirenone alone is 4.0 in the United States and 0.93 in the European Union and for the estetrol-drospirenone combination it is 2.65 and 0.44, respectively. Drospirenone alone demonstrates high rates of unscheduled bleeding and low rates of scheduled bleeding, whereas the estetrol-drospirenone combination demonstrates a predictable and regular bleeding profile for most users with a high stable rate of scheduled bleeding and a low rate of unscheduled bleeding, reported primarily as spotting only. The adverse event profiles and discontinuation rates owing to adverse events are comparable, and no clinically significant effects were observed on metabolic parameters with either product. Hemostatic assays for drospirenone do not fully evaluate all parameters although the testing that is available suggests negligible effects, whereas validated hemostatic assays demonstrate that the estetrol-drospirenone combination has limited impact on hemostasis. The introduction of 4 mg drospirenone and 15 mg estetrol with 3 mg drospirenone are valuable additions to the contraceptive market. Adding estetrol to 3 mg drospirenone provides advantages of contraceptive efficacy and a regular, predictable bleeding profile with minimal impact on hemostasis parameters.

Drospirenone and estetrol: evaluation of a newly approved novel oral contraceptive

INTRODUCTION

Estetrol (E4) is a native estrogen produced only by the fetal liver during pregnancy. E4 is the first new estrogen to be used in hormonal contraception since the introduction of oral contraceptives in 1960. Ethinyl estradiol, the most commonly used estrogen in oral contraceptives today, increases the risks of thromboembolism and has other significant hepatic impacts, which induce important drug-drug interactions. On the other hand, Phase 2 E4 characterization studies demonstrated that E4 has negligible impacts on liver, breast, and vascular endothelium due to its distinct tissue selectivity. Combined with drospirenone (DRSP), E4 offers an improved safety profile for oral contraception.

AREAS COVERED

This paper briefly highlights the unique pharmacokinetic and pharmacodynamic features of E4. The efficacy, safety, and tolerability results from the Phase 2 and 3 studies of the E4/DRSP pill are discussed to provide the reader with a thorough understanding of E4 and information to use when counseling potential users.

EXPERT OPINION

The estetrol/drospirenone oral contraceptive is effective and well tolerated and provides good cycle control. In the future, estetrol may be the estrogen of choice if subsequent evidence verifies that it reduces the risks associated with current estrogens, such as venous thromboembolism and drug-drug interactions.

Comparison of Estetrol Exposure between Women and Mice to Model Preclinical Experiments and Anticipate Human Treatment

Estetrol (E4) is a natural estrogen with promising therapeutic applications in humans. The European Medicines Agency and the Food and Drug Administration have approved the use of 15 mg E4/3 mg drospirenone for contraceptive indication. Phase III clinical trials with 15-20 mg E4 for the relief of climacteric complaints are currently running. Relevant data from preclinical animal models are needed to characterize the molecular mechanisms and the pharmacological effects of E4 and possibly to reveal new therapeutic applications and to anticipate potential adverse effects. Therefore, it is important to design experimental procedures in rodents that closely mimic or anticipate human E4 exposure. In this study, we compared the effects of E4 exposure after acute or chronic administration in women and mice. Women who received chronic E4 treatment per os at a dose of 15 mg once daily reached a steady state within 6 to 8 days, with a mean plasma concentration of 3.20 ng/mL. Importantly, with subcutaneous, intraperitoneal or oral administration of E4 in mice, a stable concentration over time that would mimic human pharmacokinetics could not be achieved. The use of osmotic minipumps continuously releasing E4 for several weeks provided an exposure profile mimicking chronic oral administration in women. Measurements of the circulating concentration of E4 in mice revealed that the mouse equivalent dose necessary to mimic human treatment does not fit with the allometric prediction. In conclusion, this study highlights the importance of precise definition of the most appropriate dose and route of administration to utilize when developing predictive preclinical animal models to mimic or anticipate specific human treatment.

Estetrol: From Preclinical to Clinical Pharmacology and Advances in the Understanding of the Molecular Mechanism of Action

Estetrol (E4) is the most recently described natural estrogen. It is produced by the human fetal liver during pregnancy and its physiological function remains unclear. E4 is the estrogenic component of a recently approved combined oral contraceptive. It is also in development for use as menopausal hormone therapy. In the context of these developments, the pharmacological activity of E4, alone or in combination with a progestin, has been extensively characterized in preclinical models as well as in clinical studies in women of reproductive age and postmenopausal women. Despite the clinical benefits, the use of oral estrogens for contraception or menopause is also associated with unwanted effects, such as an increased risk of breast cancer and thromboembolic events, due to their impact on non-target tissues. Preclinical and clinical data for E4 point to a tissue-specific activity and a more selective pharmacological profile compared with other estrogens, including a low impact on the liver and hemostasis balance. This review summarizes the characterization of the pharmacological properties of E4 as well as recent advances made in the understanding of the molecular mechanisms of action driving its activity. How the unique mode of action and the different metabolism of E4 might support its favorable benefit-risk ratio is also discussed.

Combined Oral Contraceptive Adherence and Pregnancy Rates

OBJECTIVE

To assess the relationship of adherence and pregnancy in participants using an estetrol and drospirenone combined oral contraceptive.

METHODS

We performed a secondary analysis for which we pooled data from two parallel, multicenter, phase 3 trials (United States and Canada, Europe and Russia) that enrolled participants 16-50 years of age to receive estetrol 15 mg and drospirenone 3 mg in a 24 hormone and four placebo pills regimen for up to 13 cycles. Participants reported pill intake, sexual intercourse, and other contraceptive use on paper diaries. We limited this efficacy analysis to at-risk cycles (one or more reported acts of intercourse and no other contraceptive use) in participants 16-35 years of age at screening. We excluded cycles with other contraceptive use unless pregnancy occurred in that cycle. We assessed primarily the relationship between number of pills not taken per cycle and pregnancies and, secondarily, when pregnancies occurred during product use with a test for trend and χ2 analyses as appropriate.

RESULTS

Among 2,837 participants in this analysis, 31 on-treatment pregnancies occurred during 26,455 at-risk cycles. Pregnancies occurred in 0.09%, 0.25%, 0.83%, and 1.6% of cycles in which participants reported they took all hormone pills (n=25,613 cycles) or did not take one (n=405 cycles), two (n=121 cycles), and more than two (n=314 cycles) hormone-containing pills, respectively (P<.001). No pregnancies occurred in 2,216 cycles when one or more pills were missed and missed-pill instructions were followed. All pregnancies related to not taking pills occurred in the first three cycles. Pregnancy rates ranged from 0% to 0.21% per cycle with no significant trend by cycle (P=.45).

CONCLUSION

Pregnancy occurs more frequently when combined oral contraceptive users report not taking all hormone-containing pills per 28-day cycle and exceeds 1% only when more than two pills are not taken. Pregnancies in participants who reported missed pills occurred only when missed-pill instructions were not followed. A 0.09% pregnancy risk per cycle among users of a 24 hormone and four placebo pills formulation who report taking all pills likely approximates a true method-failure rate.

FUNDING SOURCE

Estetra SRL, an affiliate company of Mithra Pharmaceuticals.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02817828 and NCT02817841.

Perception of oral contraception – do women think differently from gynaecologists?

PURPOSE

This study aimed to assess the experience and satisfaction with contraceptives and use of Combined Oral Contraceptives (COC) by women and compare their perceptions with those of gynaecologists.

METHODS

This was a multicentre survey study conducted in Portugal, during April and May, 2021 with women using contraceptives and gynaecologists. Online quantitative questionnaires were carried out.

RESULTS

A total of 1508 women and 100 gynaecologists were included. Cycle control was the pill non-contraceptive benefit most valued by gynaecologists and women. For gynaecologists, the main pill concern was the risk of thromboembolic events, but they believed that weight gain was the main concern for their patients. The pill was the most used contraceptive (70%) and women were largely (92%) satisfied. The pill was associated with health risks for 85% of users, mainly thrombosis (83%), weight gain (47%), and cancer (37%). The attributes of the pill most valued by women are contraceptive efficacy (82%), followed by low risk of thromboembolic events (68%), good cycle control (60%), non-interference with libido and mood (59%) and weight (53%).

CONCLUSION

Most women use contraceptive pills and are generally satisfied with their contraceptive. Cycle control was the most valued non-contraceptive benefit for gynaecologists and women, agreeing with physicians' beliefs about women. On the other hand, contrary to physicians' beliefs, that women's main concern is weight gain, women are mainly concerned with risks associated with contraceptives. Thromboembolic events are women's and gynaecologists most valued risk. Finally, this study indicates the need for physicians to better understand what COC users really fear.

Pharmacological and metabolic effects of drospirenone as a progestin-only pill compared to combined formulations with estrogen

The spironolactone derivative drospirenone is combined with ethinylestradiol or estetrol in combined oral contraceptives. Formulations with 17-β-estradiol are used to treat climacteric symptoms. A drospirenone-only formulation has been introduced for contraception. Here, the pharmacological properties of drospirenone, the impact of the different formulations on metabolic and laboratory parameters, and the resulting clinical implications are reviewed. Ethinylestradiol, an inhibitor of CYP metabolic enzymes, changes the pharmacokinetics of drospirenone, leading to a higher drospirenone exposure with ethinylestradiol/drospirenone compared to the drospirenone-only preparation. In addition, several metabolic alterations have been described. The impact of estetrol is less pronounced, and for 17-β-estradiol/drospirenone and drospirenone-only, decreased triglyceride and cholesterol levels were observed. Ethinylestradiol induces various pro-coagulatory factors, leading to hypercoagulability. The effect is significantly reduced with estetrol, and no influence was observed with the drospirenone-only preparation. The anti-mineralocorticoid activity of drospirenone seems to positively counteract the renin-angiotensin-aldosterone-system-activating action of ethinylestradiol. There is no influence on blood pressure with ethinylestradiol/drospirenone and estetrol/drospirenone formulations, while in clinical trials, a reduction has been observed with 17-β-estradiol/drospirenone and drospirenone-only. Anti-aldosterone activity via non-renal mineralocorticoid receptors is associated with cardiovascular health, while interactions with parathyroid hormone signaling impact bone structure and vascular calcification. Though the clinical relevance is unclear for drospirenone, data in this context are reviewed. To sum up, the advantages of drospirenone in hormonal contraception and treatment of menopausal symptoms have been demonstrated for all the formulations described here. Combination with estrogen confers benefits and risks, which must be considered.

Pooled efficacy results of estetrol/drospirenone combined oral contraception phase 3 trials

OBJECTIVE

To evaluate overall and subgroup efficacy of an estetrol (E4) 15 mg drospirenone (DRSP) 3 mg oral contraceptive in a 24/4-day regimen.

STUDY DESIGN

We pooled efficacy outcomes from 2 pivotal phase 3 contraceptive trials with E4/DRSP conducted in the United States/Canada and Europe/Russia. We assessed Pearl Index (PI; pregnancies per 100 participant-years) and 13-cycle life-table pregnancy rates in at-risk cycles (confirmed intercourse and no other contraceptive use) among participants 16 to 35 years. We calculated PI by age and further subcategorization (contraceptive history and body mass index [BMI]). We performed multivariable analysis using Cox regression to assess impact of potential confounding factors.

RESULTS

Analyses included 3027 participants, of whom 451 (14.9%) had a BMI ≥30 kg/m². The pooled PI was 1.52 (95% confidence interval 1.04-2.16) and the 13-cycle life-table pregnancy rate was 1.28% (0.83%-1.73%). We calculated unadjusted pooled PI in participants 16 to 25 years and 26 to 35 years of 1.61 (0.94-2.57) and 1.43 (0.78-2.40), respectively; in new starters and switchers of 1.88 (1.09-3.00) and 1.24 (0.68-2.08), respectively; and by BMI <25 kg/m², 25 to 29.9 kg/m², and ≥30 kg/m² of 1.14 (0.64-1.88), 2.19 (1.05-4.03), and 2.27 (0.83-4.94), respectively. In multivariable analysis, we found associations of prior pregnancy (hazard ratio [HR] 3.61[1.56-8.38]), Black race (HR 4.61[1.97-10.80]), age 16 to 25 years (HR 2.37[1.09-5.15]) and compliance <99% of expected pills (HR 4.21[2.04-8.66]) with conception.

CONCLUSION

E4/DRSP is an effective oral contraceptive overall and across subgroups stratified by age, contraceptive history, and BMI. Other than compliance, predictors of contraceptive failure are nonmodifiable.

IMPLICATIONS STATEMENT

Pooled results from two phase 3 trials demonstrate high contraceptive efficacy of the novel estetrol-drospirenone oral contraceptive. Several non-modifiable risk factors, including prior pregnancy, race, and age, are associated with higher pregnancy risk. Additional research is needed to better understand predictors of combined oral contraceptive failure.

Pooled analysis of two phase 3 trials evaluating the effects of a novel combined oral contraceptive containing estetrol/drospirenone on bleeding patterns in healthy women

OBJECTIVE

To evaluate the bleeding patterns of a new combined oral contraceptive containing estetrol (E4) 15 mg/drospirenone (DRSP) 3 mg in a 24/4-day regimen.

STUDY DESIGN

We pooled bleeding data from two parallel, open-label, 13-cycle phase 3 trials that enrolled participants 16 to 50 years old with body mass index (BMI) ≤35 kg/m². Participants reported vaginal bleeding/spotting in daily diaries. For this bleeding analysis, we included participants with at least one evaluable cycle. We calculated mean frequencies of scheduled and unscheduled bleeding/spotting episodes and median duration of bleeding/spotting episodes, and assessed associations between treatment compliance, BMI and recent hormonal contraceptive use on bleeding/spotting outcomes.

RESULTS

We included 3409 participants with 33,815 cycles. Scheduled bleeding/spotting occurred in 87.2% to 90.4% of participants/cycle, with a median duration of 4 to 5 days. Unscheduled bleeding/spotting decreased from 27.1% in Cycle 1 to 20.6% in Cycle 2 to ≤17.5% from Cycle 5 onwards. Most (66.5%) unscheduled bleeding/spotting episodes were spotting-only. Between 5.8% and 7.8% of users/cycle experienced absence of any scheduled or unscheduled bleeding/spotting. Missing one or more active pills resulted in a higher occurrence of unscheduled bleeding/spotting (adjusted odds ratio [aOR] 2.13 [95% confidence interval 1.68-2.70]) and absence of scheduled bleeding/spotting (aOR 2.36 [1.82-3.07]). Participants with a BMI ≥30 kg/m² reported more absence of scheduled bleeding/spotting (aOR 1.68 [1.37-2.05]). Switchers and starters reported similar frequencies of unscheduled bleeding/spotting (aOR 0.94 [0.83-1.07]) and absence of scheduled bleeding/spotting (aOR 1.00 [0.85-1.19]). Three percent of participants discontinued for a bleeding-related adverse event.

CONCLUSION

E4/DRSP use results in a predictable bleeding pattern with limited unscheduled bleeding/spotting. Noncompliance and BMI affect bleeding patterns.

IMPLICATIONS STATEMENT

Most estetrol/drospirenone users experience a predictable and regular bleeding pattern. Providers can educate patients about the expected bleeding patterns and should advise users that they may infrequently experience no scheduled bleeding/spotting. This information may improve user acceptability and continuation of this new oral contraceptive.

Maintaining bone health by estrogen therapy in patients with advanced prostate cancer: a narrative review

The purpose of androgen deprivation therapy (ADT) in prostate cancer (PCa), using luteinizing hormone-releasing hormone agonists (LHRHa) or gonadotrophin-releasing hormone antagonists, is to suppress the levels of testosterone. Since testosterone is the precursor of estradiol (E2), one of the major undesired effects of ADT is the concomitant loss of E2, causing among others an increased bone turnover and bone loss and an increased risk of osteoporosis and fractures. Therefore, the guidelines for ADT indicate to combine ADT routinely with bone-sparing agents such as bisphosphonates, denosumab or selective estrogen receptor modulators. However, these compounds may have side effects and some require inconvenient parenteral administration. Co-treatment with estrogens is an alternative approach to prevent bone loss and at the same time, to avoid other side effects caused by the loss of estrogens, which is the topic explored in the present narrative review. Estrogens investigated in PCa patients include parenteral or transdermal E2, diethylstilbestrol (DES), and ethinylestradiol (EE) as monotherapy, or high-dose estetrol (HDE4) combined with ADT. Cardiovascular adverse events have been reported with parenteral E2, DES and EE. Encouraging effects on bone parameters have been obtained with transdermal E2 (tE2) and HDE4, in the tE2 development program (PATCH study), and in the LHRHa/HDE4 co-treatment study (PCombi), respectively. Confirmation of the beneficial effects of estrogen therapy with tE2 or HDE4 on bone health in patients with advanced PCa is needed, with special emphasis on bone mass and fracture rate.

Venous Thromboembolism Issues in Women

The lifetime risk of venous thromboembolism (VTE) is slightly higher in women than in men. There are several issues related to VTE that are unique to women. Combined hormonal contraceptives and pregnancy increase the risk of VTE in women of childbearing age, whereas hormone replacement therapy increases the VTE risk of postmenopausal women. Hereditary thrombophilia and risk factors such as older age, obesity, or smoking contribute to the risk increase. In women diagnosed with acute hormone-related VTE who are treated with oral anticoagulants, adequate contraception is mandatory to avoid unwanted pregnancies. According to current knowledge, hormonal contraception may be continued during anticoagulant therapy but must be switched to an estrogen-free contraception method at least 6 weeks before the termination of anticoagulation. VTE is also a major cause of maternal morbidity and mortality during pregnancy and the postpartum period. Currently, assisted reproduction technologies such as in vitro fertilization are widely used to treat couples affected by infertility. Complications of fertility treatment comprise VTE cases, especially in women with ovarian hyperstimulation syndrome. With this review, we intended to focus on VTE issues in women and summarize current evidence and guideline recommendations.

A novel estetrol-containing combined oral contraceptive: European expert panel review

PURPOSE

Despite considerable advances in recently developed combined oral contraceptives (COCs), resulting in lower rates of adverse events while maintaining contraceptive efficacy, there is interest in further innovation.

MATERIALS AND METHODS

Estetrol (E4), a native oestrogen, and progestin drospirenone (DRSP) were combined in a new COC. A European expert panel reviewed the pharmacology, efficacy, and safety and tolerability of this combination. Their findings are presented as a narrative review.

RESULTS

E4 15mg/DRSP 3 mg in a 24/4 regimen provided effective contraception with good cycle control, characterised by a predictable regular bleeding pattern and minimal unscheduled bleeding, together with a good safety profile. The combination was associated with high user satisfaction, wellbeing, and minimal changes in body weight. The effects on endocrine and metabolic parameters were limited, and the combination was found to have a limited impact on liver function and lipid and carbohydrate metabolism. Moreover, its effect on several haemostatic parameters was lower than that of comparators containing ethinyl oestradiol (EE) 20mg/DRSP 3 mg and EE 30mg/levonorgestrel 150mg.

CONCLUSION

E4 15 mg/DRSP 3 mg provides safe and effective contraception, with high user satisfaction and predictable bleeding. Further research will evaluate the long-term safety of the COC.

Bleeding Patterns of Oral Contraceptives with a Cyclic Dosing Regimen: An Overview

Bleeding irregularities are one of the major reasons for discontinuation of oral contraceptives (OCs), and therefore clinicians need to set expectations during consultations. In this review we provide an overview of bleeding data of recently marketed cyclic combined OCs (COCs) and one progestin-only pill (POP). We evaluated data from phase 3 trials (≥12 months) used to gain regulatory approval. Overall, each type of OC has its own specific bleeding pattern. These patterns however were assessed by using different bleeding definitions, which hampers comparisons between products. In COCs, the estrogen balances the effects of the progestin on the endometrium, resulting in a regular bleeding pattern. However, this balance seems lost if a too low dose of ethinylestradiol (EE) (e.g., 10 µg in EE/norethindrone acetate 1 mg) is used in an attempt to lower the risk of venous thromboembolism. Replacement of EE by 17β-estradiol (E2) or E2 valerate could lead to suboptimal bleeding profile due to destabilization of the endometrium. Replacement of EE with estetrol (E4) 15 mg in the combination with drospirenone (DRSP) 3 mg is associated with a predictable and regular scheduled bleeding profile, while the POP containing DRSP 4 mg in a 24/4 regimen is associated with a higher rate of unscheduled and absence of scheduled bleeding than combined products.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2021

The second year of the COVID-19 pandemic had no adverse effect on the number of new drug approvals by the US Food and Drug Administration (FDA). Quite the contrary, with a total of 50 new drugs, 2021 belongs to the most successful FDA years. We assign these new drugs to one of three levels of innovation: (1) first drug against a condition ("first-in-indication"), (2) first drug using a novel molecular mechanism ("first-in-class"), and (3) "next-in-class", i.e., a drug using an already exploited molecular mechanism. We identify 21 first-in-class, 28 next-in-class, and only one first-in-indication drugs. By treatment area, the largest group is once again cancer drugs, many of which target specific genetic alterations. Every second drug approved in 2021 targets an orphan disease, half of them being cancers. Small molecules continue to dominate new drug approvals, followed by antibodies and non-antibody biopharmaceuticals. In 2021, the FDA continued to approve drugs without strong evidence of clinical effects, best exemplified by the aducanumab controversy.

Estetrol/Drospirenone: A Review in Oral Contraception

Estetrol/drospirenone is a combined oral contraceptive (COC) with a plant-synthesised foetal oestrogen (estetrol) and a well-established progestin (drospirenone). In preclinical models, estetrol has lower binding affinity for the oestrogen receptor-α (ER-α) in contrast to estradiol and has antagonistic properties against membrane ER-α in several tissues, including the breast, while retaining agonistic activity on receptors located in the nucleus. The low oestrogenicity of estetrol may potentially contribute to reduced thrombotic risk. Estetrol/drospirenone was an effective contraceptive in phase II and III clinical trials, with regular and predictable bleeding cycles maintained in the majority of women. Estetrol/drospirenone was generally well-tolerated with metrorrhagia reported as the most common treatment-related adverse event, which is consistent with other COCs. Cases of migraines with aura (or severe migraines), deep vein thrombosis, hyperkalaemia and depression were rarely reported during the phase III trials. Overall, estetrol/drospirenone is an effective and generally well-tolerated COC, with a potentially reduced risk of thrombosis.

In 2019, an estimated 44% of women aged 15–49 years worldwide used modern contraception methods, and in these women using modern methods, 18% used an oral contraceptive. Estetrol/drospirenone is a combined oral contraceptive (COC) which uses estetrol, a plant-synthesised oestrogen naturally produced by the human foetal liver during pregnancy, in combination with drospirenone, a well-known progestin. Combined, these hormones suppress ovulation, which constitutes their primary mode of action in preventing pregnancy. As estetrol has weaker oestrogen-related effects, it may potentially reduce the risk for blood clots. Estetrol/drospirenone was an effective contraceptive in clinical trials, and most women had regular and predictable bleeding cycles. Metrorrhagia (i.e. abnormal bleeding) was the most commonly reported treatment-related adverse effect; however, this is a common issue with hormonal contraceptives. Cases of severe migraine headaches, deep vein thrombosis, high potassium levels or depression were rarely reported during clinical trials. Estetrol/drospirenone is an effective oral contraceptive, which may offer a contraceptive option with a lower risk for blood clots. However, further research is required to confirm the reduced risk of clotting.

Estradiol Valerate vs Ethinylestradiol in Combined Oral Contraceptives: Effects on the Pituitary-Ovarian Axis

CONTEXT

Limited studies have compared the effects of combined oral contraceptives (COCs) containing natural estrogens and synthetic ethinylestradiol (EE) on reproductive hormones.

OBJECTIVE

To compare estradiol valerate (EV) + dienogest (DNG), EE + DNG, and DNG alone (active control) on levels of follicle stimulating hormone (FSH), luteinizing hormone, anti-Müllerian hormone (AMH), ovarian steroids, sex hormone binding globulin (SHBG), and the free androgen index (FAI).

METHODS

This spin-off study from a randomized trial enrolled 59 healthy, 18 to 35-year-old ovulatory women, outpatients at Helsinki and Oulu University Hospitals, Finland, who were randomized to EV 2 mg + DNG 2-3 mg (n = 20); EE 0.03 mg + DNG 2 mg (n = 20); and DNG 2 mg (n = 19) for 9 weeks. Blood samples were drawn at baseline, and at 5 and 9 weeks. Age and BMI were comparable between groups; 3 women discontinued.

RESULTS

EV + DNG suppressed FSH by -27% (-51% to -3%) (median [95% CI]) vs EE + DNG, -64% (-78 to -51), P = 0.04, but AMH levels decreased similarly by -9% (-18 to -0.1) vs -13% (-28 to 0.2), P = 0.38, respectively. EV + DNG increased SHBG levels by 56% (30% to 82%) and EE + DNG by 385% (313% to 423%), P < 0.001. Total testosterone decreased by 16% (-27% to -5%) in the EV + DNG group but it did not decrease in the EE + DNG group, whereas the FAI decreased by -39% (-54% to -25%) vs -72% (-78% to -67%), P < 0.001. DNG alone did not induce changes in any of these parameters.

CONCLUSION

Compared with EE + DNG, treatment with EV + DNG resulted in milder pituitary downregulation and reduced induction of hepatic SHBG synthesis-potentially carrying more beneficial health effects.

Profile of estetrol, a promising native estrogen for oral contraception and the relief of climacteric symptoms of menopause

INTRODUCTION

Estrogens used in women's healthcare have been associated with increased risks of venous thromboembolism (VTE) and breast cancer. Estetrol (E4), an estrogen produced by the human fetal liver, has recently been approved for the first time as a new estrogenic component of a novel combined oral contraceptive (E4/drospirenone [DRSP]) for over a decade. In phase 3 studies, E4/DRSP showed good contraceptive efficacy, a predictable bleeding pattern, and a favorable safety and tolerability profile.

AREAS COVERED

This narrative review discusses E4's pharmacological characteristics, mode of action, and the results of preclinical and clinical studies for contraception, as well as for menopause and oncology.

EXPERT OPINION

Extensive studies have elucidated the properties of E4 that underlie its favorable safety profile. While classical estrogens (such as estradiol) exert their actions via both activation of nuclear and membrane estrogen receptor α (ERα), E4 presents a specific profile of ERα activation: E4 binds and activates nuclear ERα but does not induce the activation of membrane ERα signaling pathways in specific tissues. E4 has a small effect on normal breast tissue proliferation and minimally affects hepatic parameters. This distinct profile of ERα activation, uncoupling nuclear and membrane activation, is unique.

Oestrogen component of COCs: have we finally found a replacement for ethinyl estradiol?

PURPOSE OF REVIEW

Combined oral contraceptive pills are among the most widely used contraceptive methods globally. Despite their popularity, the potential risks and side effects can lead to both high discontinuation rates and adverse outcomes including thromboembolic events. The quest for a safer alternative to the traditional ethinyl estradiol/progestin combination has led to the use of newer oestrogens. Ethinyl oestradiol alternatives will be reviewed including the newest option, estetrol, as it enters clinical use.

RECENT FINDINGS

Oestradiol, when combined with a progestin with strong endometrial activity, is a viable alternative to ethinyl estradiol in the form of oestradiol valerate and estradiol, which have been available since 2008 and 2011, respectively. Estetrol is the newest oestrogen available and is found naturally in the foetal liver. Estetrol was approved for use in 2021. All three of these alternatives have high contraceptive efficacy, similar if not improved cycle control and decreased impact on haemostatic factors as compared to ethinyl estradiol.

SUMMARY

Alternatives to ethinyl oestradiol, including the newest option of estetrol, show promise in providing comparable contraceptive efficacy with potentially lower risk of side effects and thromboembolic events.

Estetrol: A New Choice for Contraception

Estetrol (E4) is a natural estrogenic steroid that is normally produced by human fetal liver. Recent research has demonstrated that it is a potent, orally bioavailable, natural selective estrogen receptor modulator; it has a moderate affinity for both human estrogen receptor alpha (ERα) and ERβ, with a preference for ERα. Clinical studies have demonstrated possible use as an estrogen in combined oral contraceptives (COC). COCs containing E4 and drospirenone (DRSP) showed a high acceptability, tolerability, and user satisfaction also when compared to COCs containing ethinylestradiol (EE). E4/DRSP effectively inhibits ovulation, with a similar effect on endometrium thickness than that of EE-containing COCs. Low doses (15 mg) of E4 with DRSP (3 mg) showed promising results in term of bleeding pattern and cycle control, also when compared to other COCs containing synthetic estrogens. Moreover, the association has limited effects on serum lipids, liver, SHBG levels, and carbohydrate metabolism. This combination also could drive a lower risk of venous thromboembolism than EE-containing COCs. In this review, we will summarize the actual knowledge about the new E4-containing contraceptive. Further large-scale studies in the full target population are needed to provide more insights into the cardiovascular safety profile and user satisfaction of E4/DRSP.