7α,11β-Dimethyl-19-nortestosterone: a potent and selective androgen response modulator with prostate-sparing properties

Safety and Pharmacokinetics of Single-Dose Novel Oral Androgen 11β-Methyl-19-Nortestosterone-17β-Dodecylcarbonate in Men

Context

11β-Methyl-19-nortestosterone-17β-dodecylcarbonate (11β-MNTDC) is an orally bioavailable prodrug of 11β-methyl-19-nortestosterone (11β-MNT) with androgenic and progestational activity.

Objectives

(i) Quantify 11β-MNT binding to androgen and progesterone receptors. (ii) Evaluate safety, tolerability, and serum gonadotropin and testosterone suppression by 11β-MNTDC in men.

Design and Setting

(i) In vitro receptor binding and transactivation studies and (ii) randomized, double-blind, placebo-controlled single-dose, dose-escalating phase I study at two academic medical centers.

Participants and Intervention

Twelve healthy male volunteers were randomized (five active, one placebo) to escalating single oral doses (100, 200, 400, and 800 mg) of 11β-MNTDC or placebo given with or without food.

Main Outcome Measures

(i) In vitro 11β-MNT/11β-MNTDC human receptor binding and transactivation and (ii) safety and tolerability, pharmacokinetics, and quantification of serum gonadotropin and testosterone concentrations for 24 hours following dosing.

Results

11β-MNT avidly binds and activates human androgen and progesterone receptors, but 11β-MNTDC has minimal activity. Single oral doses of 11β-MNTDC were well tolerated without serious adverse events. Administration of 11β-MNTDC with food markedly increased average 11β-MNTDC and 11β-MNT serum concentrations (P < 0.001 for all doses) compared with fasting with a significant dose-related effect on average serum drug concentrations (P < 0.0001). The 200-, 400-, and 800-mg doses significantly suppressed average serum testosterone concentrations (P < 0.05).

Conclusions

A single, oral dose of 11β-MNTDC up to 800 mg administered with food is safe and well tolerated in healthy men. The active drug 11β-MNT has androgenic and progestational activity, rapidly suppresses serum testosterone, and is a promising candidate for an effective once-daily oral male hormonal contraceptive.

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.

The current state of male hormonal contraception

World population continues to grow at an unprecedented rate, doubling in a mere 50years to surpass the 7-billion milestone in 2011. This steep population growth exerts enormous pressure on the global environment. Despite the availability of numerous contraceptive choices for women, approximately half of all pregnancies are unintended and at least half of those are unwanted. Such statistics suggest that there is still a gap in contraceptive options for couples, particularly effective reversible contraceptives for men, who have few contraceptive choices. Male hormonal contraception has been an active area of research for almost 50years. The fundamental concept involves the use of exogenous hormones to suppress endogenous production of gonadotropins, testosterone, and downstream spermatogenesis. Testosterone-alone regimens are effective in many men but high dosing requirements and sub-optimal gonadotropin suppression in 10-30% of men limit their use. A number of novel combinations of testosterone and progestins have been shown to be more efficacious but still require further refinement in delivery systems and a clearer understanding of the potential short- and long-term side effects. Recently, synthetic androgens with both androgenic and progestogenic activity have been developed. These agents have the potential to be single-agent male hormonal contraceptives. Early studies of these compounds are encouraging and there is reason for optimism that these may provide safe, reversible, and reliable contraception for men in the near future.

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.

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.

A novel synthetic androgen receptor ligand, S42, works as a selective androgen receptor modulator and possesses metabolic effects with little impact on the prostate

We identified a novel synthetic steroid, S42, as a promising candidate of selective androgen receptor (AR) modulator. Results of the whole-cell binding assay using COS-7 cells exogenously expressing various steroid receptors indicated that S42 specifically binds to AR and progesterone receptor. When orchiectomized Sprague Dawley rats were administered with S42 for 3 wk, the muscle weight of the levator ani was increased as markedly as that induced by 5alpha-dihydrotestosterone (DHT), but the weight of the prostate was not elevated at any doses in contrast to DHT. The plasma concentrations of gonadotropin and adiponectin, those down-regulated by DHT, were unaffected by S42. In addition, although the plasma triglyceride level was unaffected by DHT, it was significantly reduced by S42. This effect of S42 was associated with suppression of the SRBP-1c-mediated lipogenic and insulin-desensitizing pathway in the liver and visceral fat. Taken together, S42 works as an AR agonist in muscle and as an AR antagonist in the prostate, pituitary gland, and liver, accompanying beneficial potentials on lipid metabolism.

Metabolism and excretion of anabolic steroids in doping control--new steroids and new insights

The use of anabolic steroids in sports is prohibited by the World Anti-Doping Agency. Until the 1990s, anabolic steroids were solely manufactured by pharmaceutical companies, albeit sometimes on demand from national sports agencies as part of their doping program. Recently the list of prohibited anabolic steroids in sports has grown due to the addition of numerous steroids that have been introduced on the market by non-pharmaceutical companies. Moreover, several designer steroids, specifically developed to circumvent doping control, have also been detected. Because anabolic steroids are most often intensively subjected to phase I metabolism and seldom excreted unchanged, excretion studies need to be performed in order to detect their misuse. This review attempts to summarise the results of excretion studies of recent additions to the list of prohibited steroids in sports. Additionally an update and insight on new aspects for "older" steroids with respect to doping control is given.

Dimethandrolone undecanoate: a new potent orally active androgen with progestational activity

Dimethandrolone (DMA), the 17beta-undecanoic acid ester of dimethandrolone (DMAU; 7alpha,11beta-dimethyl-19-nortestosterone) is a potent androgen currently in development for therapeutic uses in men. Cleavage of the 17beta-ester bond liberates the biologically active DMA. In this study we investigated the activity of DMAU and DMA both in vivo and in vitro. DMAU was active orally in castrate rat bioassays, and when administered sc, a single dose produced prolonged androgenic activity and suppression of LH with sustained circulating levels of DMA. DMA, other 19-norandrogens, and C-19 androgens bound to recombinant rat androgen receptor with high affinity and were equipotent in stimulating luciferase activity (EC50, 10(-10) -10(-9) M) in CV-1 cells cotransfected with a human androgen receptor expression vector and a luciferase reporter plasmid with three hormone response elements. Because various 19-norandrogens are also known to bind to progestin receptors (PR) and to possess progestational activity in vivo, we evaluated the binding affinity of DMA for rabbit PR and recombinant human PR-A and PR-B and its ability to induce PR-mediated transcription and endogenous alkaline phosphatase activity in T47DCO human breast cancer cells. DMA and related 19-norandrogens bound with high affinity to both rabbit and human PR, whereas the less active 11alpha-methyl stereoisomer of DMA and C-19 androgens showed low or negligible binding to PR. In T47DCO cells, 10(-8) M DMA and other 19-norandrogens stimulated transcription of a progestin/glucocorticoid/androgen response element-thymidine kinase-luciferase reporter plasmid to the same extent as R5020, the potent progestin promegestone (EC50, approximately 10(-9) M), but C-19 androgens had no effect. Antiprogestins were potent inhibitors of transactivation and alkaline phosphatase activity induced by DMA and other 19-norandrogens in T47DCO cells, whereas antiandrogens were weak inhibitors. DMA and DMAU also exhibited dose-dependent progestational activity in the estrogen-primed immature female rabbit, as assessed by induction of endometrial gland arborization. The dual androgenic and progestational activities of DMA make it a potential candidate for a single-agent male contraceptive as well as for androgen therapy in men, pending a successful outcome of pharmacokinetic and toxicity studies currently in progress.