Ethinyl estradiol and levonorgestrel pharmacokinetics with a low-dose transdermal contraceptive delivery system, AG200-15: a randomized controlled trial

Extended regimen of a levonorgestrel/ethinyl estradiol transdermal delivery system: Predicted serum hormone levels using a population pharmacokinetic model

OBJECTIVE

This study employed population pharmacokinetic (popPK) models to predict levonorgestrel (LNG) and ethinyl estradiol (EE) exposure after dosing with the transdermal contraceptive TWIRLA® (LNG/EE TDS) as a 12-week extended regimen in a healthy female population.

METHODS

PopPK models were developed using data from a previously published phase 1, open-label, randomized clinical trial, ATI-CL14 (NCT01243580), in 36 healthy individuals. Models used cycle 2 data from 18 individuals who received the LNG/EE TDS, delivering LNG 120 μg/day and EE 30 μg/day, followed by a 1-week TDS-free period. Noncompartmental PK analyses were performed on simulated concentration-time profiles of 12 consecutive weeks of LNG/EE TDS use.

RESULTS

The simulated concentration-time profiles and PK parameters for the simulated extended regimen indicated that predicted LNG and EE exposures at week 12 were similar to week 3 (predicted geometric mean EE area under the concentration-time curve from time 0 to 168 h [AUC0-168] on week 3 was 0.2% lower than week 12 and LNG AUC0-168 on week 3 was 0.9% lower than week 12), suggesting both were at steady state by week 3. Therefore, no notable accumulation beyond that at week 3 is predicted for LNG and EE following a 12-week extended regimen. The results are supported by the accumulation ratios based on maximum concentration and the area under the curve being similar at weeks 3 and 12 for LNG and EE.

CONCLUSION

These results indicate that a 12-week extended LNG/EE regimen would provide similar systemic hormonal exposure as that seen by week 3 in a standard 28-day regimen, without further hormonal accumulation. The data support the safe use of a non-daily, low-dose hormonal contraceptive in an extended regimen but should be confirmed in a clinical PK study.

New Contraception Update — Annovera, Phexxi, Slynd, and Twirla

Purpose of Review

In this review, we discuss the efficacy, safety, and benefits of four new contraceptive products available in the USA, specifically Annovera, Phexxi, Slynd, and Twirla.

Recent Findings

Annovera is a vaginal ring releasing ethinyl estradiol and segesterone acetate that can be used for up to one year (13 cycles), offering patients an effective, user-controlled option that may improve contraceptive access for those in low-resource settings or those with barriers to retrieving monthly prescriptions; however, given limited efficacy and safety data in people with body mass index (BMI) > 29 kg/m2, clinicians may consider whether Annovera is an appropriate contraceptive method for obese patients if there are other acceptable alternatives. Phexxi prescription-only vaginal gel is a user-controlled, non-hormonal, on-demand contraceptive method that represents a novel addition to the market with its additional uses as a personal lubricant and as a potential microbicide for urogenital infection prevention. Slynd, a drospirenone-only pill, provides more flexibility for delayed or missed pills while maintaining efficacy and a more favorable bleeding profile compared with previously available progestin-only pills. Lastly, Twirla is a transdermal patch releasing ethinyl estradiol and levonorgestrel that offers users an additional option for a user-controlled, combined hormonal contraceptive method without daily dosing; however, prescription is limited to patients with BMI < 30 kg/m2 due to decreased efficacy and VTE events in people with obesity.

Summary

The addition of these products expands the available options for pregnancy prevention to address unmet contraceptive needs.

Hormonal Contraception: Systemic Estrogen and Progestin Preparations

Combined hormonal contraception (CHC) are short-acting, reversible methods containing both estrogen and progestin. Available CHC methods include combined oral contraceptives, transdermal patches, and vaginal rings. The combined oral contraceptive remains the most commonly used contraceptive method in the United States. The general principles of CHC will be reviewed, including mechanism of action and effectiveness. Unless otherwise stated, these principles apply to all CHCs. When discussing clinical studies and specific considerations related only to pills, patches, or rings, the method(s) will be specified. Words that specify sex are used when discussing studies in which sex was specified.

The new low-dose transdermal contraceptive system (Twirla®): results from preclinical and Phase III trials

A new low-dose, once-a-week contraceptive transdermal delivery system (TDS) with 2.3-mg ethinyl estradiol (EE) and 2.6-mg levonorgestrel (LNG; Twirla^®) has recently been approved by the US FDA for contraception of women with BMI <30 kg/m². The rationale for developing this new patch, the preclinical study results and the results from two innovative Phase III clinical trials demonstrate that this patch has an acceptable Pearl index (4.3%) for its indicated users and has safety and tolerability comparable to other similar dose oral combined hormonal contraceptives. This new TDS provides an improvement over the existing TDS products, with significantly lower steady-state estrogen exposure, a level equal to that with 30-µg EE containing oral contraceptives.

Efficacy, safety, and tolerability of a levonorgestrel/ethinyl estradiol transdermal delivery system: Phase 3 clinical trial results

OBJECTIVE

To assess the contraceptive efficacy, safety, and tolerability of a contraceptive transdermal delivery system, (TDS; TWIRLA^Ⓡ) containing levonorgestrel (LNG) and ethinyl estradiol (EE).

STUDY DESIGN

This single-arm, open-label, multicenter, 1-year (13 cycle), phase 3 study enrolled sexually active women ≥18 years old at risk for pregnancy irrespective of body mass index (BMI). Women used patches in 28-day cycles (3 consecutive administrations of 7-day patches followed by 7 days off-treatment/patch-free week). We assessed contraceptive efficacy by the Pearl Index (PI) in women 18 to 35 years, excluding cycles without intercourse or when other contraceptive methods were used.

RESULTS

The study enrolled 2032 demographically diverse women in the US, of which 35.3% had a BMI ≥30 kg/m². In the primary efficacy analysis, the PI (95% confidence interval) was 5.8 (4.5-7.2) pregnancies per 100 woman-years. PIs trended higher as BMI increased; the PI was 4.3 (2.9-5.8) in women with BMI <30 kg/m² and 8.6 (5.8-11.5) in women with BMI ≥30 kg/m². Hormone-related treatment-emergent adverse events included nausea (4.1%) and headache (3.6%); 11% of women discontinued due to adverse events. Four women (all with BMIs ≥30 kg/m²) reported thromboembolic events considered related to treatment.

CONCLUSIONS

The low-dose LNG/EE TDS was effective in preventing pregnancy in a population of women representative of US demographics. Efficacy was reduced in women with BMI ≥30 kg/m². The TDS safety and tolerability profile was consistent with other similar dose combined hormonal contraceptives. Results of this phase 3 study supported the US Food and Drug Administration approval of TWIRLA^Ⓡ for prevention of pregnancy in women with BMI <30 kg/m².

IMPLICATIONS

TDS (120 µg/day levonorgestrel and 30 µg/day ethinyl estradiol) is an effective, low-dose transdermal contraceptive patch with favorable tolerability profile approved for prevention of pregnancy in women with BMI <30 kg/m². TDS has reduced effectiveness in women with BMI ≥30 kg/m².

New phosphate derivatives of betulin as anticancer agents: Synthesis, crystal structure, and molecular docking study

Betulin derivatives exhibit an antiproliferative activity and have been tested for many cancer cell lines. This paper describes a new series of 3-phosphate derivatives of betulin bearing different substituents at C28 position. The synthesized compounds were tested in vitro for their antiproliferative effect against human leukemia (MV-4-11 and CCRF/CEM), lung carcinoma (A549), prostate cancer (DU 145), melanoma (Hs 294T) cell lines, and murine leukemia P388. To explore the possible mechanism of anticancer activity for the most in vitro active compounds (4, 5, 7 and 8) and betulin, molecular docking was performed to the binding sites of potential anticancer targets, described for the various triterpene derivatives, including topoisomerase I and II, epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGFR), transcription factor NF-κB, anti-apoptotic protein Bcl-2 and peroxisome proliferator-activated receptor (PPARγ). According to the results of the docking, the best fit to the binding pocket of PPARγ was shown by compound 4.

Safety and tolerability of a new low-dose contraceptive patch in obese and nonobese women

OBJECTIVE

The safety and tolerability of a new low-dose levonorgestrel/ethinyl estradiol (LNG/EE) contraceptive patch was compared with 2 combination oral contraceptives in 2 clinical studies in which approximately 30% of enrolled participants were obese.

STUDY DESIGN

Two phase 3, open-label, randomized, parallel-group, multicenter trials compared the LNG/EE contraceptive patch (n = 1579) with combination oral contraceptives (n = 581) in healthy women 17-40 years of age. Combination oral contraceptives were LNG 100 μg per EE 20 μg (combination oral contraceptive 20; n = 375) or LNG 150 μg per EE 30 μg (combination oral contraceptive 30; n = 206). Safety and tolerability data from the 2 trials were evaluated in integrated safety analyses.

RESULTS

Treatment-emergent adverse events of 2% or greater in the LNG/EE contraceptive patch were nasopharyngitis (5.2%), nausea (4.1%), upper respiratory infection (3.5%), headache (3.4%), sinusitis (2.9%), cervical dysplasia (2.3%), and urinary tract infection (2.1%). Including skin reaction-related treatment-emergent adverse events, the proportion of women who experienced any treatment-emergent adverse event was similar among women randomized to the contraceptive patch (47.5%), the combination oral contraceptive 20 (47.4%), or the combination oral contraceptive 30 (46.8%). The incidence of treatment-emergent adverse events was similar in obese vs nonobese participants in all groups. Serious adverse events occurred in less than 1% of participants in any of the treatment groups.

CONCLUSION

The LNG/EE contraceptive patch and combination oral contraceptives were well tolerated and associated with similar treatment-emergent adverse event incidences in obese and nonobese women.

Applying emerging science to contraception research: implications for the clinic

Emerging science will make an important contribution towards the development of improved contraceptives. While long-acting reversible contraceptives remain the most effective method, new user-controlled, mid-acting methods will avoid the need for procedures requiring trained providers. Contraceptives combined with other agents may bring additional health benefits, such as dual protection against both pregnancy and sexually transmitted infections. Emerging research areas in proteomics allowed the discovery of new reproductive targets that may lead to non-hormonal contraceptives for both men and women. Current research objectives include the improvement of existing contraceptive methods, as well as discovery of new materials able to deliver new molecules more specifically to their target without systemic actions.

Contraception technology: past, present and future

Steady progress in contraception research has been achieved over the past 50 years. Hormonal and nonhormonal modern contraceptives have improved women's lives by reducing different health conditions that contributed to considerable morbidity. However, the contraceptives available today are not suitable to all users, and the need to expand contraceptive choices still exists. Novel products such as new implants, contraceptive vaginal rings, transdermal patches and newer combinations of oral contraceptives have recently been introduced in family planning programs, and hormonal contraception is widely used for spacing and limiting births. Concerns over the adverse effects of hormonal contraceptives have led to research and development of new combinations with improved metabolic profile. Recent developments include use of natural compounds such as estradiol and estradiol valerate with the hope to decrease thrombotic risk, in combination with newer progestins derived from the progesterone structure or from spirolactone, in order to avoid the androgenic effects. Progesterone antagonists and progesterone receptor modulators are highly effective in blocking ovulation and preventing follicular rupture and are undergoing investigations in the form of oral pills and in semi-long-acting delivery systems. Future developments also include the combination of a contraceptive with an antiretroviral agent for dual contraception and protection against sexually transmitted diseases, to be used before intercourse or on demand, as well as for continuous use in dual-protection rings. Although clinical trials of male contraception have reflected promising results, limited involvement of industry in that area of research has decreased the likelihood of having a male method available in the current decade. Development of nonhormonal methods is still at an early stage of research, with the identification of specific targets within the reproductive system in ovaries and testes, as well as interactions between spermatozoa and ova. It is hoped that the introduction of new methods with additional health benefits would help women and couples with unmet needs to obtain access to a wider range of contraceptives with improved acceptability.