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

Synthetic androgens for male contraception

High global rates of unintended pregnancy (>40% of all pregnancies) are relatively stagnant despite a broad array of female contraceptive options. Data suggest many men are enthusiastic to utilize novel, reversible, male contraceptives, particularly those that may be administered orally. Hormonal male contraception utilizes androgens or androgen-progestin combinations to exploit endocrine negative feedback, interrupting the hypothalamic-pituitary-testicular axis to suppress spermatogenesis. Modifications of testosterone allow for tailoring of steroid activity and show promise as single agent hormonal male contraceptives. The addition of progestin activity by molecular modification of testosterone could enhance the degree and speed of sperm suppression compared to testosterone alone using a single, exogenous steroid. Moreover, modifications that block reduction of testosterone to dihydrotestosterone could diminish androgenic stimulation of prostate tissue. This review summarizes data in the development of modified androgens for male hormonal contraception and suggest a path forward for these molecules in helping to fill the gap in contraceptive technologies for men.

Male Hormonal Contraception-Current Stage of Knowledge

Male hormonal contraception has been the focus of extensive research efforts aimed at identifying effective and reversible methods for male fertility control. This review summarizes the current state of knowledge, key achievements, and future directions in the development of male hormonal contraception. A review was conducted using the PubMed, Embase, and Scopus databases. The search strategy included terms such as "male hormonal contraception", "Nestorone", "7α,11β-Dimethyl-19-nortestosterone 17β-undecanoate (DMAU)" and "11β-methyl-19-nortestosterone 17β-dodecylcarbonate (11β-MNTDC)". A total of 107 references were analyzed to synthesize the most relevant findings regarding the hormonal contraceptive agents under investigation. The review outlines historical and recent advancements in male hormonal contraception, highlighting compounds that have demonstrated limitations in effectiveness, side effects, or inconvenient administration. Notable candidates under study include 7α-methyl-19-nortestosterone (MENT), DMAU, 11β-MNTDC, and the combination of segesterone acetate with testosterone in gel form. These agents show promise due to their ability to suppress follicle-stimulating hormone (FSH) and luteinizing hormone (LH), leading to effective spermatogenesis inhibition with minimal side effects. Additionally, the phenomenon of spermatogenic rebound is considered. Among the investigated agents, oral DMAU, 11β-MNTDC, and the Nestorone-testosterone gel appear to be the most promising candidates for male hormonal contraception due to their high efficacy, user-friendly administration, and favorable safety profiles. However, further large-scale clinical trials are necessary to confirm their long-term effects on human health and fertility, ensuring their viability as future contraceptive options.

Testosterone and male contraception

PURPOSE OF REVIEW

Rates of unintended pregnancy have remained relatively stagnant for many years, despite a broad array of female contraceptive options. Recent restrictions on access to abortion in some countries have increased the urgency for expanding contraceptive options. Increasing data suggest men are keen to utilize novel reversible male contraceptives.

RECENT FINDINGS

Despite decades of clinical research in male contraception, no reversible hormonal product currently exists. Nestorone/testosterone, among other novel androgens, shows promise to finally move to pivotal Phase 3 studies and introduction to the marketplace.

SUMMARY

Hormonal male contraception utilizes androgens or androgen-progestin combinations to exploit negative feedback that regulates the hypothalamic-pituitary-testicular axis. By suppressing release of gonadotropins, these agents markedly decrease endogenous testosterone production, lower intratesticular testosterone and suppress spermatogenesis. The addition of a progestin enhances the degree and speed of sperm suppression. The androgen component preserves a state of symptomatic eugonadism in the male. There is growing demand and acceptance of male contraceptive options in various forms. As these formulations progress through stages of drug development, regulatory oversight and communication with developers around safety and efficacy standards and garnering industry support for advancing the production of male contraceptives will be imperative.

Male contraception: narrative review of ongoing research

BACKGROUND

Since the release of the combined oral contraceptive pill in 1960, women have shouldered the burden of contraception and family planning. Over 60 years later, this is still the case as the only practical, effective contraceptive options available to men are condoms and vasectomy. However, there are now a variety of promising hormonal and non-hormonal male contraceptive options being studied. The purpose of this narrative review is to provide clinicians and laypeople with focused, up-to-date descriptions of novel strategies and targets for male contraception. We include a cautiously optimistic discussion of benefits and potential drawbacks, highlighting several methods in preclinical and clinical stages of development.

RESULTS

As of June 2023, two hormonal male contraceptive methods are undergoing phase II clinical trials for safety and efficacy. A large-scale, international phase IIb trial investigating efficacy of transdermal segesterone acetate (Nestorone) plus testosterone gel has enrolled over 460 couples with completion estimated for late 2024. A second hormonal method, dimethandrolone undecanoate, is in two clinical trials focusing on safety, pharmacodynamics, suppression of spermatogenesis and hormones; the first of these two is estimated for completion in December 2024. There are also several non-hormonal methods with strong potential in preclinical stages of development.

CONCLUSIONS

There exist several hurdles to novel male contraception. Therapeutic development takes decades of time, meticulous work, and financial investment, but with so many strong candidates it is our hope that there will soon be several safe, effective, and reversible contraceptive options available to male patients.

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.

Testosterone Replacement Therapy in Hypogonadal Men

All approved testosterone replacement methods, when used according to recommendations, can restore normal serum testosterone concentrations, and relieve symptoms in most hypogonadal men. Selection of the method depends on the patient's preference with advice from the physician. Dose adjustment is possible with most delivery methods but may not be necessary in all hypogonadal men. The use of hepatotoxic androgens must be avoided. Testosterone treatment induces reversible suppression of spermatogenesis; if fertility is desired in the near future, human chronic gonadotropin, selective estrogen receptor modulator, estrogen antagonist, or an aromatase inhibitor that stimulates endogenous testosterone production may be used.

Comparison of metabolic effects of the progestational androgens dimethandrolone undecanoate and 11β-MNTDC in healthy men

BACKGROUND

Dimethandrolone (DMA) and 11β-methyl-19-nortestosterone (11β-MNT) are two novel compounds with both androgenic and progestational activity that are under investigation as potential male hormonal contraceptives. Their metabolic effects have never been compared in men.

OBJECTIVE

Assess for changes in insulin sensitivity and adiponectin and compare the metabolic effects of these two novel androgens.

MATERIALS/METHODS

In two clinical trials of DMA undecanoate (DMAU) and 11β-MNT dodecylcarbonate (11β-MNTDC), oral prodrugs of DMA and 11β-MNT, healthy men received drug, or placebo for 28 days. Insulin and adiponectin assays were performed on stored samples. Mixed model analyses were performed to compare the effects of the two drugs. Student's t test, or the non-parametric Kruskal-Wallis test as appropriate, was used to evaluate for an effect of active drug versus placebo.

RESULTS

Class effects were seen, with decrease in HDL-C and SHBG, and increase in weight and hematocrit, with no statistically significant differences between the two compounds. No changes in fasting glucose, fasting insulin, or HOMA-IR were seen with either compound. There was a slight decrease in adiponectin with DMAU that was not seen with 11β-MNTDC. An increase in LDL-C was seen with 11β-MNTDC but not with DMAU.

DISCUSSION

There were no significant changes in insulin resistance after 28 days of oral administration of these novel androgens despite a mild increase in weight. There may be subtle differences in their metabolic impacts that should be explored in future studies.

CONCLUSION

Changes in metabolic parameters should be carefully monitored when investigating androgenic compounds.

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.