Clinical trials in male hormonal contraception

Ca2+ homeostasis and male fertility: a target for a new male contraceptive system

Ca2+ is a key secondary messenger that determines sperm motility patterns. Mammalian sperm undergo capacitation, a process to acquire fertilizing ability, in the female reproductive tract. Capacitated sperm change their flagellar waveform to develop hyperactivated motility, which is crucial for successful sperm navigation to the eggs and fertilization. The sperm-specific channel, CATSPER, and an ATPase transporter, PMCA4, serve as major paths for Ca2+ influx and efflux, respectively, in sperm. The ionic paths coordinate Ca2+ homeostasis in the sperm, and their loss-of-function impairs sperm motility, to cause male infertility. In this review, we summarize the physiological significance of these two Ca2+ gates and suggest their potential applications in novel male contraceptives.

Reversible Contraception in Males: An Obtainable Target?

The last few decades have brought contraception to the forefront of research, with great strides made in effectively targeting and optimizing the physiology, pharmacology, and delivery processes that prevent pregnancy. However, these advances still predominantly target female contraceptives for the prevention of contraception, whereas targeting the male sex has lagged far behind. This has led to a marked deficiency in safe and effective male contraceptive agents, resulting in a heavy dependence on female contraceptives to prevent unwanted and unplanned pregnancies. Current research in the veterinary field and in rodents highlights several promising avenues whereby novel, safe, and effective male contraceptive alternatives are being developed-with an emphasis on reduced side effects and reversibility potential. This review aims to discuss current and novel male contraceptives (both human and veterinary formulations) while highlighting their efficacy, advantages, and disadvantages.

Why we need more methods for male contraception

The US Supreme Court decision against abortion has once again triggered the call for male contraception. However, in addition to existing methods, there are further reasons why pharmacological reversible easy-to-use male contraception should be available. Green activists and environmentalists have to recognize that overpopulation consume resources. Medical progress results in increasing life expectancy and must be combined with contraception. Sharing the risks of contraception among partners and "Reproductive Autonomy for All" are ethical issues. The resistance of the pharmacological industry to becoming partners in male contraception must be overcome by public financial subsidies and popular demand.

The novel BRDT inhibitor NHWD870 shows potential as a male contraceptive in mice

Small molecule inhibitors of the bromodomain and extraterminal domain (BET) family proteins have emerged as promising options not only for the treatment of multiple cancers but also for disturbing the process of sperm maturation with potential for use as viable contraceptive targets. In this study, we find that the BET family inhibitor NHWD870 and BRDT can bind well in vitro through bioinformatics software prediction and protein binding inhibition experiments. NHWD870 can produce a good contraceptive effect through animal experiments in vivo, and the fertility can be restored to normal after drug withdrawal. Transcriptomics and proteomics results suggest that NHWD870 affects pathways related to spermatogenesis and maturation, further contributing to the male infertility phenotype. Our results show that NHWD870 can induce a complete and reversible contraceptive effect in mice, which is stronger than that of JQ1 and its synthesized derivatives. This study is expected to eventually lead to clinical trials.

Androgens in male contraception

Rates of unplanned pregnancies are high globally, burdening women and families. Efforts to develop male contraceptive agents have been thwarted by unacceptable failure rates, side effects and a dearth of pharmaceutical industry involvement. Hormonal male contraception consists of exogenous androgens which exert negative feedback on the hypothalamic-pituitary-gonadal axis and suppress gonadotropin production. This in turn suppresses testicular testosterone production and sperm maturation. Addition of a progestin suppresses spermatogenesis more effectively in men. Contraceptive efficacy studies in couples have shown male hormonal methods are effective and reversible, but also may come with side effects related to sexual desire, acne and serum cholesterol and inconvenient methods of dosing and delivery. Recently, novel androgens as potential contraceptive agents are being evaluated in early clinical trials and look to overcome these drawbacks. Here we summarize landmark studies of prototype male hormonal contraceptives, showcasing recent advances and future prospects in this important area of public health.

Management of male factor infertility: position statement from the Italian Society of Andrology and Sexual Medicine (SIAMS) : Endorsing Organization: Italian Society of Embryology, Reproduction, and Research (SIERR)

PURPOSE

Infertility affects 15-20% of couples and male factors are present in about half of the cases. For many aspects related to the diagnostic and therapeutic approach of male factor infertility, there is no general consensus, and the clinical approach is not uniform.

METHODS

In the present document by the Italian Society of Andrology and Sexual Medicine (SIAMS), endorsed by the Italian Society of Embryology, Reproduction, and Research (SIERR), we propose evidence-based recommendations for the diagnosis, treatment, and management of male factor infertility to improve patient and couple care.

RESULTS

Components of the initial evaluation should include at minimum medical history, physical examination, and semen analysis. Semen microbiological examination, endocrine assessment, and imaging are suggested in most men and recommended when specific risk factors for infertility exist or first-step analyses showed abnormalities. Full examination including genetic tests, testicular cytology/histology, or additional tests on sperm is clinically oriented and based on the results of previous investigations. For treatment purposes, the identification of the specific cause and the pathogenetic mechanism is advisable. At least, distinguishing pre-testicular, testicular, and post-testicular forms is essential. Treatment should be couple-oriented, including lifestyle modifications, etiologic therapies, empirical treatments, and ART on the basis of best evidence and with a gradual approach.

CONCLUSION

These Guidelines are based on two principal aspects: they are couple-oriented and place high value in assessing, preventing, and treating risk factors for infertility. These Guidelines also highlighted that male infertility and in particular testicular function might be a mirror of general health of a man.

Knowledge and Perception Regarding the Development and Acceptability of Male Contraceptives Among Pharmacists: A Mixed Sequential Method

Community pharmacists play a crucial role in providing comprehensive patient education regarding contraception methods. This study aims to investigate Jordanian pharmacists’ knowledge and perceptions toward male oral contraceptive pills (OCPs). A mixed-explanatory sequential method was divided into two phases. The first was a self-administered electronic survey that was distributed to community pharmacists/trainees in Jordan. The second phase was carried out through online semi-structured in-depth interviews targeting the maximum variation purposive sample of community pharmacists. A total of 158 (response rate 98%) questionnaires were included in the analysis. The majority of the participants were female (n = 118, 74.2%). In terms of knowledge, only 25% of participants acknowledged the presence of male OCPs and almost half were uncertain about the mechanism of action and the possible uses. The findings of the interviews confirmed a relatively negative perception toward male OCPs and the identified barriers to male OCPs were cultural norms, side effects, and poor compliance. It is argued that there is a negative perception toward male OCPs due to the majority of pharmacists not believing such products will be successful in Jordan. Once these pills are approved for their effectiveness and safety, men may need further education and encouragement to take an active role in family planning along with their partners.

Update on Novel Hormonal and Nonhormonal Male Contraceptive Development

BACKGROUND

The advent of new methods of male contraception would increase contraceptive options for men and women and advance male contraceptive agency. Pharmaceutical R&D for male contraception has been dormant since the 1990s. The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) has supported a contraceptive development program since 1969 and supports most ongoing hormonal male contraceptive development. Nonhormonal methods are in earlier stages of development.

CONTENT

Several hormonal male contraceptive agents have entered clinical trials. Novel single agent products being evaluated include dimethandrolone undecanoate, 11β-methyl-nortestosterone dodecylcarbonate, and 7α-methyl-19-nortestosterone. A contraceptive efficacy trial of Nestorone®/testosterone gel is underway. Potential nonhormonal methods are at preclinical stages of development. Many nonhormonal male contraceptive targets that affect sperm production, sperm function, or sperm transport have been identified.

SUMMARY

NICHD supports development of reversible male contraceptive agents. Other organizations such as the World Health Organization, the Population Council, and the Male Contraception Initiative are pursuing male contraceptive development, but industry involvement remains limited.

Emerging approaches to male contraception

Despite significant interests in contraception by men, effective methods of male contraception are limited to vasectomy and condoms. Recently, there have been several promising advances in male contraceptive research. This review will update readers on recent research in both hormonal and nonhormonal approaches to male contraception. Hormonal approaches to male contraception have been stymied by adverse effects, formulations requiring injections or implants, a 5% to10% nonresponse rate, as well as poor understanding of user acceptability. In the last several years, research has focused on novel, orally bioavailable androgens such as dimethandrolone undecanoate and 11β-methyl-19-nor-testosterone. Additionally, combinations of a topical testosterone gel combined with a gel containing segesterone acetate, a potent progestin, have shown promise in clinical trials recently. Simultaneously, significant preclinical progress has been made in several approaches to nonhormonal male contraceptives, including compounds that inhibit sperm motility such as eppin, compounds that inhibit retinoic acid binding or biosynthesis, and reversible approaches to obstruction of the vas deferens. It is imperative for these areas of research to continue making strides so that there is a gamut of contraceptive options for couples to choose from. Some of these approaches will hopefully reach clinical utility soon, greatly improving contraceptive choice for couples.

Young Adult Males' Perspectives of Male Hormonal Contraception

OBJECTIVE

To evaluate the willingness of young adult males to use male hormonal contraception and to determine the most desirable formulation.

METHODS

An institutional review board-approved survey measuring the willingness to use MHC was dispersed to two distinct populations: University of Cincinnati postgraduate programs and Cincinnati Health Department clinics. Questions on the survey allowed for the collection of demographic characteristics, as well as the preferred method of MHC, and concerns regarding potential adverse effects. This survey was directed at young adult males; therefore, only male participants who were 18 to 35 years old were included for analysis. Results were reported as frequencies in each group and χ² analyses were performed to compare groups, with a P < 0.05 considered significant.

RESULTS

Of 162 total survey participants, 45% would use MHC, whereas 30.9% were unsure and 23.5% would not use MHC. Overall, the University of Cincinnati survey population was more likely to be interested in using MHC than the Cincinnati Health Department population (P < 0.05). In both populations, most were interested in using the injectable form. Cited concerns deterring participants from using MHC were different between these two populations, with University of Cincinnati participants more frequently expressing concerns about possible failure of the contraceptive method, whereas Cincinnati Health Department participants had concerns about potential adverse effects (P < 0.001).

CONCLUSIONS

There is significant interest among young adult males in using various forms of MHC, especially in injectable form. Differences in views of MHC were seen in two distinct male populations. Specifically, males who achieved a higher level of education, were employed, or in a relationship were found to more frequently be willing to use MHC. With further research and funding, MHC may serve as a significant way to decrease unintended pregnancies in the future.

Dimethandrolone Undecanoate, a Novel, Nonaromatizable Androgen, Increases P1NP in Healthy Men Over 28 Days

CONTEXT

Dimethandrolone undecanoate (DMAU) is being developed as a male contraceptive. Daily oral administration of DMAU, a potent androgen that is not aromatized, markedly suppresses serum testosterone (T) and estradiol (E2) in healthy men. E2 deficiency can increase bone resorption in men.

OBJECTIVE

This work aimed to assess changes in bone turnover markers with DMAU administration in a 28-day study.

DESIGN

A randomized, double-blind, placebo-controlled study was conducted.

SETTING

This study took place at 2 academic medical centers.

PARTICIPANTS

Healthy men, age 18 to50 years (n = 81), participated.

INTERVENTION

Men received 0, 100, 200, or 400 mg of oral DMAU for 28 days. Serum C-terminal telopeptide of type I collagen (CTX; bone resorption marker) and procollagen type I amino-terminal propeptide (P1NP; bone formation marker) were measured on days 1 and 28.

MAIN OUTCOME MEASURES

Changes in bone turnover markers and serum hormones over the treatment period were measured.

RESULTS

On day 28, median serum T and E2 were markedly suppressed in all treatment groups vs placebo (P < .001 for both). Percentage change (%) in serum P1NP significantly differed across treatment groups (P = .007): Serum P1NP significantly increased in the 200 mg (5%, interquartile range [IQR] -7% to 27%) and 400 mg (22%, IQR -1% to 40%) groups relative to placebo (-8%, IQR -20% to 0%). Change (%) in serum CTX did not differ between groups (P = .09).

CONCLUSIONS

DMAU administration for 28 days to healthy men leads to marked suppression of serum T and E2, yet increases P1NP, a serum marker of bone formation. Longer-term studies of the potent androgen DMAU are warranted to determine its impact on bone health in men.

Male Hormonal Contraception

The economic and public health burdens of unplanned pregnancies are evident globally. Since the introduction of the condom >300 years ago, assumptions about male willingness to participate in contraception, as well as concerns about failure rates and side effects, have stagnated the development of additional reversible male contraceptives. However, changing attitudes and recent research advances have generated renewed interest in developing reversible male contraceptives. To achieve effective and reversible suppression of spermatogenesis, male hormonal contraception relies on suppression of testicular testosterone and sperm production using an androgen-progestin combination. While these may be associated with side effects—changes in libido, weight, hematocrit, and cholesterol—recently, novel androgens and progestins have shown promise for a “male pill” with reduced side effects. Here we summarize landmark studies in male contraceptive development, showcase the most recent advances, and look into the future of this field, which has the potential to greatly impact global public health.

Male Contraceptive Development: Update on Novel Hormonal and Nonhormonal Methods

BACKGROUND

Development of new methods of male contraception would address an unmet need for men to control their fertility and could increase contraceptive options for women. Pharmaceutical research and development for male contraception was active in the 1990s but has been virtually abandoned. The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) has supported a contraceptive development program since 1969 and supports the majority of hormonal male contraceptive development. Nonhormonal methods are also in development but are at earlier stages.

CONTENT

Several hormonal male contraceptive agents have entered clinical trials. Single-agent products being evaluated include dimethandrolone undecanoate, 11β-methyl-nortestosterone dodecyl carbonate, and 7α-methyl-19-nortestosterone. A contraceptive efficacy trial of Nestorone^® gel and testosterone gel in a single application will begin in 2018. Potential nonhormonal methods are at preclinical stages of development. Many nonhormonal male contraceptive targets that affect either sperm production or sperm function have been identified. Targeted pathways include the retinoic acid pathway, bromodomain and extraterminal proteins, and pathways for Sertoli cell-germ cell adhesion or sperm motility. Druggable targets include CatSper, the sperm Na+/K+-exchanger, TSSK, HIPK4, EPPIN, and ADAMs family proteins. Development of a procedure to reversibly block the vas deferens (initially developed in India in the 1980s) is undergoing early stage research in the US under the trade name Vasalgel™.

SUMMARY

NICHD has supported the development of reversible male contraceptive agents. Other organizations such as the World Health Organization and the Population Council are pursuing male contraceptive development, but industry involvement remains dormant.

Recent Developments in Male Contraception

Unplanned pregnancies are an ongoing global burden, posing health and economic risks for women, children, and families. Advances in male contraception have been historically stymied by concerning failure rates, problematic side effects, and perceived market limitations. However, increased interest in reliable and reversible options for male contraception have resulted in resurgent efforts to introduce novel contraceptives for men. Hormonal male contraception relies on exogenous androgens and progestogens that suppress gonadotropin production, thereby suppressing testicular testosterone and sperm production. In many men, effective suppression of spermatogenesis can be achieved by androgen-progestin combination therapy. Small-scale contraceptive efficacy studies in couples have demonstrated effectiveness and reversibility with male hormonal methods, but side effects related to mood, sexual desire and cholesterol remain concerning. A number of novel androgens have reached clinical testing as potential contraceptive agents; many of these have both androgenic and progestogenic action in a single, modified steroid, thereby holding promise as single-agent contraceptives. Currently, these novel steroids hold promise as both a "male pill" and long-acting injections. Among non-hormonal methods, studies of reversible vaso-occlusive methods (polymers that block transport of sperm through the vas deferens) are ongoing, but reliable reversibility and long-term safety in men have not been established. Proteins involved in sperm maturation and motility are attractive targets, but to date both specificity and biologic redundancy have been challenges for drug development. In this review, we aim to summarize landmark studies on male contraception, highlight the most recent advances and future development in this important field of public health and medicine.

Latheef S, Sharun K, Khurana SK, K. A, Tiwari R, Bhatt P, K. V, Chaicumpa W. Role of Antisperm Antibodies in Infertility, Pregnancy, and Potential forContraceptive and Antifertility Vaccine Designs: Research Progress and Pioneering Vision

Sperm of humans, non-human primates, and other mammalian subjects is considered to be antigenic. The effect of changes in autoimmunity on reproductive cells such as spermatozoa and oocytes play a critical but indistinct role in fertility. Antisperm antibodies (ASAs) are invariably present in both females and males. However, the degree of ASA occurrence may vary according to individual and gender. Although the extent of infertility due to ASAs alone is yet to be determined, it has been found in almost 9-12% of patients who are infertile due to different causes. Postcoital presence of spermatozoa in the reproductive tract of women is not a contributory factor in ASA generation. However, ASA generation may be induced by trauma to the vaginal mucosa, or by anal or oral sex resulting in the deposition of sperm inside the digestive tract. It is strongly believed that, in humans and other species, at least some antibodies may bind to sperm antigens, causing infertility. This form of infertility is termed as immunological infertility, which may be accompanied by impairment of fertility, even in individuals with normozoospermia. Researchers target ASAs for two major reasons: (i) to elucidate the association between ASAs and infertility, the reason ASAs causes infertility, and the mechanism underlying ASA-mediated infertility; and (ii) to assess the potential of ASAs as a contraceptive in humans in case ASAs influences infertility. Therefore, this review explores the potential application of ASAs in the development of anti-spermatozoa vaccines for contraceptive purposes. The usefulness of ASAs for diagnosing obstructive azoospermia, salpingitis, and oligoasthenoteratozoospermia has been reviewed extensively. Important patents pertaining to potential candidates for spermatozoa-derived vaccines that may be utilized as contraceptives are discussed in depth. Antifertility vaccines, as well as treatments for ASA-related infertility, are also highlighted. This review will address many unresolved issues regarding mechanisms involving ASAs in the diagnosis, as well as prognoses, of male infertility. More documented scientific reports are cited to support the mechanisms underlying the potential role of ASA in infertility. The usefulness of sperm antigens or ASAs (recombinant) in human and wild or captive animal contraceptive vaccines has been revealed through research but is yet to be validated via clinical testing.

ENDOCRINE HISTORY: The history of discovery, synthesis and development of testosterone for clinical use

As the most important male hormone, testosterone has an impact on almost all organs and body functions. The biological effects of testosterone and the testes have been known since antiquity, long before testosterone was identified as the active agent. Practical applications of this knowledge were castration of males to produce obedient servants, for punishment, for preservation of the prepubertal soprano voice and even for treatment of diseases. Testes were used in organotherapy and transplanted as treatment for symptoms of hypogonadism on a large scale, although these practices had only placebo effects. In reaction to such malpractice in the first half of the 20th century science and the young pharmaceutical industry initiated the search for the male hormone. After several detours together with their teams in 1935, Ernst Laqueur (Amsterdam) isolated and Adolf Butenandt (Gdansk) as well as Leopold Ruzicka (Zürich) synthesized testosterone. Since then testosterone has been available for clinical use. However, when given orally, testosterone is inactivated in the liver, so that parenteral forms of administration or modifications of the molecule had to be found. Over 85 years the testosterone preparations have been slowly improved so that now physiological serum levels can be achieved.

Effects of 28 Days of Oral Dimethandrolone Undecanoate in Healthy Men: A Prototype Male Pill

CONTEXT

Dimethandrolone (DMA) has androgenic and progestational activity. Single oral doses of DMA undecanoate (DMAU) were well tolerated and reversibly suppressed serum LH and testosterone (T) in men.

OBJECTIVE

Assess safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of oral DMAU.

DESIGN

Double-blind, randomized, placebo-controlled study.

SETTING

Two academic medical centers.

PARTICIPANTS

Healthy men (18 to 50 years).

INTERVENTIONS

One hundred men received DMAU [0, 100, 200, or 400 mg, formulated in castor oil/benzyl benzoate (C) or powder (P)] for 28 days. Subjects underwent 24-hour PK sampling on days 1 and 28 and twice weekly ambulatory visits throughout treatment.

MAIN OUTCOME MEASURES

Primary outcomes were safety and tolerability parameters (vitals, laboratory data, mood, and sexual function scores) and adverse events. Secondary outcomes were drug PK profiles and PD effects (serum LH, FSH, and sex hormones).

RESULTS

Eighty-two subjects completed the study and were included in the analysis. There were no serious adverse events. No clinically significant changes developed in safety laboratory parameters. A significant dose effect was seen for weight, hematocrit, high-density lipoprotein cholesterol, corrected QT interval, and sexual desire. Serum 24-hour average concentrations of DMAU and DMA showed dose-related increases (P < 0.001). All six subjects in the P400 group and 12 of 13 subjects in the C400 group achieved marked suppression of LH and FSH (<1.0 IU/L) and serum T (<50 ng/dL).

CONCLUSIONS

Daily oral administration of DMAU for 28 days in healthy men is well tolerated. Doses of ≥200 mg markedly suppress serum T, LH, and FSH. These results support further testing of DMAU as a male contraceptive.

Update on male hormonal contraception

Despite increases in female contraceptive options, 40-45% of pregnancies across the world are still unplanned. While several effective female contraceptive methods have been developed, contraceptive choices for men are still limited to the male condom with its high failure rates and to vasectomies, which are invasive and not reliably reversible. Several studies have demonstrated a great interest among men and women for effective, reversible, and safe male contraceptive methods. Over the years, numerous studies have been performed to develop male hormonal and nonhormonal safe and effective contraceptives. A variety of new molecules are under development as oral or transdermal hormonal contraceptives for men demonstrating few side effects. In our overpopulated world, the development and commercialization of a male contraceptive method that will allow both men and women to take an active role in family planning is mandatory and further research on this topic is required.

Are men ready to use thermal male contraception? Acceptability in two French populations: New fathers and new providers

Background

Since the 1970s, international research has actively pursued hormonal male contraception (HMC) and, to a lesser extent, thermal male contraception (TMC). Although the efficacy of TMC has been confirmed in limited populations, its acceptability has not been studied in either potential users or potential prescribers.

Methods

A cross-sectional descriptive multicentre study of potential male users of TMC (new fathers) and potential prescribers of TMC (new providers) was conducted between November 2016 and February 2017.The participants completed a 3-part survey, and their responses were evaluated to i) determine their socio-demographic profiles; ii) identify personal experiences with contraception; and iii) gauge the participants’ knowledge, interest and preference for male contraception, particularly TMC. For new providers only, the survey included a fourth part to evaluate professional experience with male contraception.

Results

The participation rate was 51% for new fathers (305 NFs) and 34% for new providers (300 NPs, including 97 men (male new providers, MNPs) and 203 women (female new providers, FNPs)). Only 3% of NFs and 15% of NPs knew about TMC (including 26% of the MNPs and 10% of the FNPs, p<0.01). After reading information on TMC, new fathers were significantly less willing to try TMC (29%) than were new providers (40%) (p<0.01). The 3 main advantages of TMC for the new fathers included the following factors: “natural” (52%), “without side effects” (38%) and “non-hormonal” (36%). The main disadvantages were “lengthy wear time” (56%), “daily undergarment wear” (43%) and “concern about possible discomfort” (39%).

Conclusions

Young male and female providers have limited knowledge of male contraception, are interested in further information and would generally prescribe TMC to their patients. Successful expansion of the use of male contraception, including TMC, would require distribution of better information to potential users and providers.

The future of male contraception: a fertile ground

The continued and rapid expansion of the Earth’s population mandates the need for safe and effective measures of contraception. While a plethora of options exist for women, methods of contraception for the male partner are limited to condoms and vasectomy. The sequela of this discrepancy has led to the family planning burden falling disproportionately on the female partner. For the past several decades, extensive research has been undertaken exploring the feasibility of hormonal male contraception. This proposed method of contraception has focused on suppressing spermatogenesis by exploiting the hypothalamic-pituitary-gonadal (HPG) axis. Beginning with proof of concept studies in the early nineties, administration of testosterone in healthy male subjects has been shown to be an efficacious method of inducing sterility. Owing to ethnic differences in spermatogenesis suppression and the comparatively low rate of azoospermia in Caucasian men with androgen-only regimens, investigators have explored the addition of progestins to further enhance the efficacy of hormonal contraception. Though studies have revealed promise with androgen-progestin regimens, the lack of long-term studies has precluded the development of a marketable product. Recently, more research has been directed towards identifying non-hormonal alternatives to male contraception. These non-hormonal options have ranged from the development of devices facilitating reversible occlusion of the vas deferens lumen to medications disrupting various pathways in the process of spermatogenesis. Underlying the development of hormonal and non-hormonal strategies is the shared enthusiasm men and women have towards these male directed methods. The willingness of couples to pursue these alternatives combined with the global need to reduce the psychological and socioeconomic implications of unintended pregnancy ensures that research will continue to bring this goal to fruition.

Comprehensive functional enrichment analysis of male infertility

Spermatogenesis is a multifactorial process that forms differentiated sperm cells in a complex microenvironment. This process involves the genome, epigenome, transcriptome, and proteome to ensure the stability of the spermatogonia and supporting cells. The identification of signaling pathways linked to infertility has been hampered by the inherent complexity and multifactorial aspects of spermatogenesis. Systems biology is a promising approach to unveil underlying signaling pathways and genes and identify putative biomarkers. In this study, we analyzed thirteen microarray libraries of infertile humans and mice, and different classes of male infertility were compared using differentially expressed genes and functional enrichment analysis. We found regulatory processes, immune response, glutathione transferase and muscle tissue development to be among the most common biological processes in up-regulated genes, and genes involved in spermatogenesis were down-regulated in maturation arrest (MArrest) and oligospermia cases. We also observed the overexpression of genes involved in steroid metabolism in post-meiotic and meiotic arrest. Furthermore, we found that the infertile mouse model most similar to human MArrest was the Dazap1 mutant mouse. The results of this study could help elucidate features of infertility etiology and provide the basis for diagnostic markers.

Comparison of the single dose pharmacokinetics, pharmacodynamics, and safety of two novel oral formulations of dimethandrolone undecanoate (DMAU): a potential oral, male contraceptive

Dimethandrolone (DMA, 7α,11β-dimethyl-19-nortestosterone) has both androgenic and progestational activities, ideal properties for a male hormonal contraceptive. In vivo, dimethandrolone undecanoate (DMAU) is hydrolyzed to DMA. We showed previously that single oral doses of DMAU powder in capsule taken with food are well tolerated and effective at suppressing both LH and testosterone (T), but absorption was low. We compared the pharmacokinetics and pharmacodynamics of two new formulations of DMAU, in castor oil and in self-emulsifying drug delivery systems (SEDDS), with the previously tested powder formulation. DMAU was dosed orally in healthy adult male volunteers at two academic medical centers. For each formulation tested in this double-blind, placebo-controlled study, 10 men received single, escalating, oral doses of DMAU (100, 200, and 400 mg) and two subjects received placebo. All doses were evaluated for both fasting and with a high fat meal. All three formulations were well tolerated without clinically significant changes in vital signs, blood counts, or serum chemistries. For all formulations, DMA and DMAU showed higher maximum (p < 0.007) and average concentrations (p < 0.002) at the 400 mg dose, compared with the 200 mg dose. The powder formulation resulted in a lower conversion of DMAU to DMA (p = 0.027) compared with both castor oil and SEDDS formulations. DMAU in SEDDS given fasting resulted in higher serum DMA and DMAU concentrations compared to the other two formulations. Serum LH and sex hormone concentrations were suppressed by all formulations of 200 and 400 mg DMAU when administered with food, but only the SEDDS formulation was effectively suppressed serum T when given fasting. We conclude that while all three formulations of oral DMAU are effective and well tolerated when administered with food, DMAU in oil and SEDDS increased conversion to DMA, and SEDDS may have some effectiveness when given fasting. These properties might be advantageous for the application of DMAU as a male contraceptive.

Efficacy and Safety of an Injectable Combination Hormonal Contraceptive for Men

CONTEXT

The development of a safe and effective reversible method of male contraception is still an unmet need.

OBJECTIVE

Evaluation of suppression of spermatogenesis and contraceptive protection by coadministered im injections of progestogen and testosterone.

DESIGN

Prospective multicentre study.

SETTING

Ten study centers.

PARTICIPANTS

Healthy men, aged 18-45 years, and their 18- to 38-year-old female partners, both without known fertility problems.

INTERVENTION

Intramuscular injections of 200-mg norethisterone enanthate combined with 1000-mg testosterone undecanoate, administered every 8 weeks.

MAIN OUTCOMES MEASURES

Suppression of spermatogenesis by ejaculate analysis, contraceptive protection by pregnancy rate.

RESULTS

Of the 320 participants, 95.9 of 100 continuing users (95% confidence interval [CI], 92.8-97.9) suppressed to a sperm concentration less than or equal to 1 million/mL within 24 weeks (Kaplan-Meier method). During the efficacy phase of up to 56 weeks, 4 pregnancies occurred among the partners of the 266 male participants, with the rate of 1.57 per 100 continuing users (95% CI, 0.59-4.14). The cumulative reversibility of suppression of spermatogenesis after 52 weeks of recovery was 94.8 per 100 continuing users (95% CI, 91.5-97.1). The most common adverse events were acne, injection site pain, increased libido, and mood disorders. Following the recommendation of an external safety review committee the recruitment and hormone injections were terminated early.

CONCLUSIONS

The study regimen led to near-complete and reversible suppression of spermatogenesis. The contraceptive efficacy was relatively good compared with other reversible methods available for men. The frequencies of mild to moderate mood disorders were relatively high.

Beyond the Condom: Frontiers in Male Contraception

Nearly half of all pregnancies worldwide are unplanned, despite numerous contraceptive options available. No new contraceptive method has been developed for men since the invention of condom. Nevertheless, more than 25% of contraception worldwide relies on male methods. Therefore, novel effective methods of male contraception are of interest. Herein we review the physiologic basis for both male hormonal and nonhormonal methods of contraception. We review the history of male hormonal contraception development, current hormonal agents in development, as well as the potential risks and benefits of male hormonal contraception options for men. Nonhormonal methods reviewed will include both pharmacological and mechanical approaches in development, with specific focus on methods which inhibit the testicular retinoic acid synthesis and action. Multiple hormonal and nonhormonal methods of male contraception are in the drug development pathway, with the hope that a reversible, reliable, safe method of male contraception will be available to couples in the not too distant future.

Male hormonal contraception: looking back and moving forward

Despite numerous contraceptive options available to women, approximately half of all pregnancies in the United States and worldwide are unplanned. Women and men support the development of reversible male contraception strategies, but none have been brought to market. Herein we review the physiologic basis for male hormonal contraception, the history of male hormonal contraception development, currents agents in development as well as the potential risks and benefits of male hormonal contraception for men.

MECHANISMS IN ENDOCRINOLOGY: Medical consequences of doping with anabolic androgenic steroids: effects on reproductive functions

Anabolic androgenic steroids (AASs) are appearance and performance-enhancing drugs (APEDs) used in competitive athletics, in recreational sports, and by body-builders. The global lifetime prevalence of AASs abuse is 6.4% for males and 1.6% for women. Many AASs, often obtained from the internet and dubious sources, have not undergone proper testing and are consumed at extremely high doses and in irrational combinations, also along with other drugs. Controlled clinical trials investigating undesired side effects are lacking because ethical restrictions prevent exposing volunteers to potentially toxic regimens, obscuring a causal relationship between AASs abuse and possible sequelae. Because of the negative feedback in the regulation of the hypothalamic-pituitary-gonadal axis, in men AASs cause reversible suppression of spermatogenesis, testicular atrophy, infertility, and erectile dysfunction (anabolic steroid-induced hypogonadism). Should spermatogenesis not recover after AASs abuse, a pre-existing fertility disorder may have resurfaced. AASs frequently cause gynecomastia and acne. In women, AASs may disrupt ovarian function. Chronic strenuous physical activity leads to menstrual irregularities and, in severe cases, to the female athlete triad (low energy intake, menstrual disorders and low bone mass), making it difficult to disentangle the effects of sports and AASs. Acne, hirsutism and (irreversible) deepening of the voice are further consequences of AASs misuse. There is no evidence that AASs cause breast carcinoma. Detecting AASs misuse through the control network of the World Anti-Doping Agency (WADA) not only aims to guarantee fair conditions for athletes, but also to protect them from medical sequelae of AASs abuse.

Single, escalating dose pharmacokinetics, safety and food effects of a new oral androgen dimethandrolone undecanoate in man: a prototype oral male hormonal contraceptive

The novel androgen, dimethandrolone (DMA) has both androgenic and progestational activities, properties that may maximize gonadotropin suppression. We assessed the pharmacokinetics of dimethandrolone undecanoate (DMAU), an orally bioavailable, longer acting ester of DMA, for male contraceptive development. Our objective was to examine the safety and pharmacokinetics of single, escalating doses of DMAU (powder in capsule formulation) administered orally with or without food in healthy men. We conducted a randomized, double-blind Phase 1 study. For each dose of DMAU (25-800 mg), 10 male volunteers received DMAU and two received placebo at two academic medical centres. DMAU was administered both fasting and after a high-fat meal (200-800 mg doses). Serial serum samples were collected over 24 h following each dose. DMAU was well tolerated without significant effects on vital signs, safety laboratory tests or electrocardiograms. When administered while fasting, serum DMA (active compound) was detectable in only 4/10 participants after the 800 mg dose. When administered with a 50% fat meal, serum DMA was detectable in all participants given 200 mg DMAU and showed a dose-incremental increase up to 800 mg, with peak levels 4-8 h after taking the dose. Serum gonadotropins and sex hormone concentrations were significantly suppressed 12 h after DMAU administration with food at doses above 200 mg. This first-in-man study demonstrated that a single, oral dose of DMAU up to 800 mg is safe. A high-fat meal markedly improved DMAU/DMA pharmacokinetics.

[Male contraception]

Contraception allows within a heterosexual couple to have a more fulfilling as possible sexuality while protecting against the occurrence of unintended pregnancy. In a majority of couples, contraception is assumed by women. Currently, male contraceptive methods most commonly used are the male condom and vasectomy. Many other strategies, including hormonal contraceptive regimens, have been proposed and evaluated. The purpose of this review is to present an overview of the various current and future male contraceptive methods.

Endogenous sex hormones and risk of venous thromboembolism in women and men

BACKGROUND

Use of oral contraceptives with estrogen and hormone replacement therapy with estrogen or testosterone are associated with increased risk of venous thromboembolism (VTE). However, whether endogenous estradiol and testosterone concentrations are also associated with risk of VTE is unknown.

OBJECTIVE

We tested the hypothesis that elevated endogenous total estradiol and total testosterone concentrations are associated with increased risk of VTE in the general population.

METHODS

We studied 4658 women, not receiving exogenous estrogen, and 4673 men from the 1981-1983 Copenhagen City Heart Study, who had estradiol and testosterone concentrations measured. Of these, 636 developed VTE (deep venous thrombosis [DVT] and/or pulmonary embolism [PE]) during a follow-up of 21 years (range, 0.02-32 years). Associations between endogenous estradiol and testosterone concentrations and risk of VTE were estimated by Cox proportional hazards regression with time-dependent covariates and corrected for regression dilution bias.

RESULTS

Multifactorially adjusted hazard ratios of VTE for individuals with estradiol levels >75th vs. ≤25th percentile were 0.84 (95%CI, 0.25-2.85), 1.05 (0.53-2.08) and 1.05 (0.03-35.13) for pre- and post-menopausal women and men, respectively. For testosterone, corresponding risk estimates were 0.64 (0.03-12.32), 1.11 (0.66-1.86) and 1.30 (0.62-2.73). In addition, no associations were observed between extreme hormone percentiles (>95th vs. ≤75th) and risk of DVT, PE or recurrent VTE.

CONCLUSION

This prospective study suggests that high endogenous concentrations of estradiol and testosterone in women and men in the general population are not associated with increased risk of VTE, DVT or PE.

Developments in contraception

INTRODUCTION

Although the contraceptive options for women have expanded considerably in the last decade, these methods are often not being offered to women as choices because clinicians are not well informed, limiting the ability of women to control their fertility.

AREAS COVERED

Areas covered include the use of oestradiol instead of ethinyl oestradiol and improved progestogens utilised in hormonal contraceptives, and new delivery systems have enabled the development of long-acting methods, which require less action on the part of the user, and thereby, reduce failure rates. Effective emergency contraceptive methods have become more readily available over the counter. However, male contraception, despite much research, still remains elusive.

EXPERT OPINION

This manuscript will provide an assessment of recent advances and controversies in contraception and make suggestions about improved availability.

Testosterone use in the male infertility population: prescribing patterns and effects on semen and hormonal parameters

OBJECTIVE

To analyze how frequently and why men presenting with infertility take testosterone (T) and if negative effects of T on semen parameters are reversed following cessation.

DESIGN

Analysis of a prospectively collected database.

SETTING

Male Infertility clinic.

PATIENT(S)

Men presenting for fertility evaluation from 2008 to 2012.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The frequency and reason for T use in the infertile male population, and semen and hormonal parameters while on T and following discontinuation.

RESULT(S)

A total of 59/4,400 men (1.3%) reported taking T. T was prescribed by a variety of physicians, including endocrinologists (24%), general practitioners (17%), urologists (15%), gynecologists (5%), and reproductive endocrinologists (3%). Only one of the men admitted that he had obtained T from an illicit source. More than 82% of men were prescribed T for the treatment of hypogonadism, but surprisingly, 12% (7/59) were prescribed T to treat their infertility. While on T, 88.4% of men were azoospermic, but by 6 months after T cessation, 65% of the men without other known causes for azoospermia recovered spermatogenesis.

CONCLUSION(S)

In Canada, T was not commonly used by men presenting for fertility investigation (1.3%). Close to 2/3 of infertile men using T recovered spermatogenesis within 6 months of T discontinuation.

Oral contraceptives usage patterns: study of knowledge, attitudes and experience in Belgrade female medical students

PURPOSE

The purpose of this survey was to quantify oral contraceptive pill (OCP) use and to analyze attitudes and knowledge about the pill in a sample of female medical students.

METHODS

A cross-sectional study, conducted between November 28 and December 20, 2011, included 464 female participants from the Faculty of Medicine, University of Belgrade. Data were collected before the start of compulsory practical sessions in the classrooms through a 37-item questionnaire and assessed statistically.

RESULTS

Prevalence of OCP use was 11.3 %. Highest proportion of the pill use was in the third year (15.4 %). Approximately, 61 % used the pill as a therapy for dysmenorrhea. Difference in knowledge scores was observed between users and non-users (t = 3.596, p < 0.001). Advancing year at the faculty was highly statistically significantly associated with greater knowledge about health effects of the pill (ρ = 0.506, p < 0.001). There was no difference regarding attitude score among users and non-users (t = -0.9, p = 0.369). In the multivariate regression model the knowledge score was the only predictor of pill use.

CONCLUSION

The results of our survey indicate that oral contraceptive pill requires further promotion and reproductive health education in a broader context.

Experimental endocrine manipulation by contraceptive regimen in the male marmoset (Callithrix jacchus)

Marmosets are used as preclinical model in reproductive research. In contrast to other primates, they display short gestation times rendering this species valid for exploration of effects on fertility. However, their peculiar endocrine regulation differs from a those of macaques and humans. We subjected male marmosets to previously clinically tested hormonal regimens that are known to effectively suppress spermatogenesis. Beside a control group, seven groups (each n=6) were investigated for different periods of up to 42 months: regimen I, (four groups) received testosterone undecanoate (TU) and norethisterone enanthate (NETE); regimen II, (two groups) received TU and NETE followed by NETE only; and regimen III, (one group) received NETE only. Testicular volume, cell ploidy and histology, endocrine changes and fertility were monitored weekly. TU and NETE and initial TU and NETE treatment followed by NETE failed to suppress spermatogenesis and fertility. Testicular volumes dropped, although spermatogenesis was only mildly affected; however, testicular cellular composition remained stable. Serum testosterone dropped when NETE was given alone but the animals remained fertile. Compared with controls, no significant changes were observed in sperm motility and fertility. Administration of TU and NETE affected testicular function only mildly, indicating that the regulatory role of chorionic gonadotrophin and testosterone on spermatogenesis is obviously limited and testicular function is maintained, although the endocrine axis is affected by the treatment. In conclusion, marmosets showed a different response to regimens of male contraception from macaques or men and have to be considered as a problematic model for preclinical trials of male hormonal contraception.

What do male medical students know about the pill? study of knowledge and attitudes at the University of Belgrade

BACKGROUND

Women have been traditionally more involved in birth control than men. The purpose of this survey is to analyze knowledge of and attitudes towards oral contraceptives (OC) use in a population of male medical students of the Faculty of Medicine, Belgrade, Serbia.

METHODS

In November/December 2011, a total of 237 male medical students were recruited at the Faculty of Medicine before the start of compulsory practical sessions in their classrooms. Data were obtained through a 26-item questionnaire regarding knowledge of and attitude towards OC use.

RESULTS

Less than a half (40.4%) had a partner and 3.2% did not know whether their partner used the pill. Approximately one fifth of the students (28.5%) did not inform themselves about the pill at all. The average knowledge score differed according to the relationship status (Z = -3.414, p = 0.001). The average attitude score did not statistically differ according to the relationship status (Z = -1.384, p = 0.166). An advanced study year was statistically associated with higher knowledge and attitude scores (ρ = 0.575, p < 0.001; ρ = 0.206, p = 0.002, respectively).

CONCLUSION

Our students demonstrated a moderate level of comprehension. The results of our study indicate that the use of the OC pill needs further promotion to raise awareness of male involvement in health-related decisions of their partners.

Pharmacokinetics of testosterone and estradiol gel preparations in healthy young men

The paucity of pharmacokinetic data on testosterone gel formulations and absence of such data on estradiol administration in healthy young men constitutes a fundamental gap of knowledge in behavioral endocrinological research. We addressed this issue in a double-blind and placebo controlled study in which we applied a topical gel containing either 150mg of testosterone (N=10), 2mg of estradiol (N=8) or a respective placebo (N=10) to 28 healthy young men. We then assessed serum concentrations of estradiol and testosterone in one hour intervals up to seven hours after drug application, measured LH, SHBG and cortisol levels once at baseline and three, four as well as six hours after gel administration. Treatment with testosterone gel resulted in maximum total serum testosterone concentration three hours after administration and did not suppress LH, cortisol and SHBG levels at any time point. Administration of estradiol gel led to maximum estradiol serum concentration two hours after administration. There was no suppression of cortisol, SHBG and absolute LH levels. We report here, for the first time, pharmacokinetic data on both high dose testosterone and estradiol gel application in healthy young males. The proposed model will assist in the design of future studies that seek to establish causality between testosterone and estradiol gel administration and behavioral as well as neurophysiological effects.

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.

Male hormonal contraception: potential risks and benefits

An effective, safe, reversible, and acceptable method of contraception is an important component of reproductive health and provides the opportunity of shared responsibility for family planning for both partners. Female hormonal contraceptives have been proven to be safe, reversible, available and widely acceptable by different populations. In contrast, male hormonal contraception, despite significant progress showing contraceptive efficacy comparable to female hormonal methods during last three decades, has not yet led to an approved product. Safety of a pharmaceutical product is an appropriate concern but the majority of male hormonal contraceptive clinical trials have not reported significant short term safety concerns. While the absence of serious adverse effects is encouraging, the studies have been designed for efficacy endpoints not long term safety. In this review we summarize potential risks and benefits of putative male hormonal contraceptives on reproductive and non-reproductive organs. While the review covers what we believe will be the likely class of drugs used for male hormonal contraception a true assessment of long term risks and benefits cannot be achieved without an available product.

Does ethnicity matter in male hormonal contraceptive efficacy?

The development of male hormonal contraception has progressed significantly during the last three decades. The ultimate goal is to produce an effective, safe and reversible male method of contraception that are within reach of and can be used by all men globally. This review aims to outline the recent developments in male hormonal contraception with special emphasis on how ethnicity influences acceptability, extent of sperm suppression, and rate of recovery of spermatogenesis. Baseline differences in testicular histomorphology and testosterone metabolism between East Asian and Caucasian men have been reported, but whether this contributes significantly to varying degrees of sperm suppression in response to exogenous testosterone therapy is less known. Testosterone alone male hormonal contraceptive regimens are effective and applicable for East Asian men, and less so for Caucasians. Combinations of progestins with androgens are sufficient to optimize effectiveness of suppression and applicability to all ethnicities. New compounds such as steroidal or non-steroidal selective androgen receptor modulators with dual androgenic and progestational activities are potential compounds for further development as male hormonal contraceptive methods. At the present time, combined androgen and progestin contraceptive regimens appear to be effective, safe, reversible and convenient to use for all men with ethnic, cultural and environmental differences. Further refinements on the hormonal agent, methods of delivery, and dose optimization of the androgen relative to the progestin are necessary. This goal mandates further investment and large clinical trials in multiethnic populations to better define safety and efficacy.