Danazol, sold as Danocrine and other brand names, is a medication used in the treatment of endometriosis, fibrocystic breast disease, hereditary angioedema and other conditions. It is taken by mouth.
Steroid sulfatase (STS), or steryl-sulfatase, formerly known as arylsulfatase C, is a sulfatase enzyme involved in the metabolism of steroids. It is encoded by the STS gene.
Estrone sulfate, also known as E1S, E1SO4 and estrone 3-sulfate, is a natural, endogenous steroid and an estrogen ester and conjugate.
An estrogen ester is an ester of an estrogen, most typically of estradiol but also of other estrogens such as estrone, estriol, and even nonsteroidal estrogens like diethylstilbestrol. Esterification renders estradiol into a prodrug of estradiol with increased resistance to first-pass metabolism, slightly improving its oral bioavailability. In addition, estrogen esters have increased lipophilicity, which results in a longer duration when given by intramuscular or subcutaneous injection due to the formation of a long-lasting local depot in muscle and fat. Conversely, this is not the case with intravenous injection or oral administration. Estrogen esters are rapidly hydrolyzed into their parent estrogen by esterases once they have been released from the depot. Because estradiol esters are prodrugs of estradiol, they are considered to be natural and bioidentical forms of estrogen.
A steroidogenesis inhibitor, also known as a steroid biosynthesis inhibitor, is a type of drug which inhibits one or more of the enzymes that are involved in the process of steroidogenesis, the biosynthesis of endogenous steroids and steroid hormones. They may inhibit the production of cholesterol and other sterols, sex steroids such as androgens, estrogens, and progestogens, corticosteroids such as glucocorticoids and mineralocorticoids, and neurosteroids. They are used in the treatment of a variety of medical conditions that depend on endogenous steroids.
Ethinylestradiol sulfonate (EES), sold under the brand names Deposiston and Turisteron among others, is an estrogen medication which has been used in birth control pills for women and in the treatment of prostate cancer in men. It has also been investigated in the treatment of breast cancer in women. The medication was combined with norethisterone acetate in birth control pills. EES is taken by mouth once per week.
A steroid ester is an ester of a steroid. They include androgen esters, estrogen esters, progestogen esters, and corticosteroid esters. Steroid esters may be naturally occurring/endogenous like DHEA sulfate or synthetic like estradiol valerate. Esterification is useful because it is often able to render the parent steroid into a prodrug of itself with altered chemical properties such as improved metabolic stability, water solubility, and/or lipophilicity. This, in turn, can enhance pharmacokinetics, for instance by improving the steroid's bioavailability and/or conferring depot activity and hence an extended duration with intramuscular or subcutaneous injection.
Estradiol sulfate (E2S), or 17β-estradiol 3-sulfate, is a natural, endogenous steroid and an estrogen ester. E2S itself is biologically inactive, but it can be converted by steroid sulfatase into estradiol, which is a potent estrogen. Simultaneously, estrogen sulfotransferases convert estradiol to E2S, resulting in an equilibrium between the two steroids in various tissues. Estrone and E2S are the two immediate metabolic sources of estradiol. E2S can also be metabolized into estrone sulfate (E1S), which in turn can be converted into estrone and estradiol. Circulating concentrations of E2S are much lower than those of E1S. High concentrations of E2S are present in breast tissue, and E2S has been implicated in the biology of breast cancer via serving as an active reservoir of estradiol.
Irosustat is an orally active, irreversible, nonsteroidal inhibitor of steroid sulfatase (STS) and member of the aryl sulfamate ester class of drugs that was under development by Sterix Ltd and Ipsen for the treatment of hormone-sensitive cancers such as breast cancer, prostate cancer, and endometrial cancer but has not yet been marketed. The drug was first designed and synthesized in the group of Professor Barry V L Potter at the Department of Pharmacy & Pharmacology, University of Bath, working together with Professor Michael J. Reed at Imperial College, London and its initial development was undertaken through the university spin-out company Sterix Ltd and overseen by Cancer Research UK (CRUK). Results of the "first-in-class" clinical trial in breast cancer of an STS inhibitor in humans were published in 2006 and dose optimisation studies and further clinical data have been reported.
Estradiol sulfamate, or estradiol-3-O-sulfamate, is a steroid sulfatase (STS) inhibitor which is under development for the treatment of endometriosis. It is the C3 sulfamate ester of estradiol, and was originally thought to be a prodrug of estradiol.
Estrone sulfate (E1S) is an estrogen medication and naturally occurring steroid hormone. It is used in menopausal hormone therapy among other indications. As the sodium salt, it is the major estrogen component of conjugated estrogens (Premarin) and esterified estrogens. In addition, E1S is used on its own as the piperazine salt estropipate. The compound also occurs as a major and important metabolite of estradiol and estrone. E1S is most commonly taken by mouth, but in the form of Premarin can also be taken by parenteral routes such as transdermal, vaginal, and injection.
EC508, also known as estradiol 17β-(1- -L-proline), is an estrogen which is under development by Evestra for use in menopausal hormone therapy and as a hormonal contraceptive for the prevention of pregnancy in women. It is an orally active estrogen ester – specifically, a C17β sulfonamide–proline ester of the natural and bioidentical estrogen estradiol – and acts as a prodrug of estradiol in the body. However, unlike oral estradiol and conventional oral estradiol esters such as estradiol valerate, EC508 undergoes little or no first-pass metabolism, has high oral bioavailability, and does not have disproportionate estrogenic effects in the liver. As such, it has a variety of desirable advantages over oral estradiol, similarly to parenteral estradiol, but with the convenience of oral administration. EC508 is a candidate with the potential to replace not only oral estradiol in clinical practice, but also ethinylestradiol in oral contraceptives. Evestra intends to seek Investigational New Drug status for EC508 in the second quarter of 2018.
EC586, also known as testosterone 17β-(1- -L-proline), is an androgen and anabolic steroid which is under development by Evestra for use in androgen replacement therapy in men. It is an orally active androgen ester – specifically, a C17β sulfonamide–proline ester of the natural and bioidentical androgen testosterone – and acts as a prodrug of testosterone in the body. However, unlike oral testosterone and conventional oral testosterone esters such as testosterone undecanoate, EC586 has high oral potency, may undergo little or no first-pass metabolism, and may not have disproportionate androgenic effects in the liver. As such, it may have a variety of desirable advantages over oral testosterone, similarly to parenteral testosterone, but with the convenience of oral administration. Evestra intends to seek Investigational New Drug status for EC586 in the fourth quarter of 2018.
Estriol sulfamate, or estriol 3-O-sulfamate, is a synthetic estrogen and estrogen ester which was never marketed. It is the C3 sulfamate ester of estriol. The drug shows substantially improved oral estrogenic potency relative to estriol in rats but without an increase in hepatic estrogenic potency. However, the closely related compound estradiol sulfamate (E2MATE) failed to show estrogenic activity in humans, which is due to the fact that it is additionally a highly potent inhibitor of steroid sulfatase which regulates the estrogenicity of such compounds and thus it prevents its own bioactivation into estradiol.
Ethinylestradiol sulfamate, or 17α-ethynylestradiol 3-O-sulfamate, is a synthetic estrogen and estrogen ester which was never marketed. It is the C3 sulfamate ester of ethinylestradiol. The drug shows considerably improved oral estrogenic potency (uterotrophic) relative to ethinylestradiol in rats but without an increase in hepatic estrogenic potency. Related compounds like ethinylestradiol N,N-diethylsulfamate (J271) and ethinylestradiol pyrrolidinosulfonate (J272) have also been developed, and have similar properties in animals. However, the closely related compound estradiol sulfamate (E2MATE) failed to show estrogenic activity in humans, which is due to the fact that it is additionally a highly potent inhibitor of steroid sulfatase and prevents its own bioactivation into estradiol.
Ethinylestradiol sulfate, also known as 17α-ethynylestradiol 3-sulfate, is an estrogen ester – specifically, the C3 sulfuric acid (sulfate) ester of the synthetic estrogen ethinylestradiol (EE) – and is the major metabolite of EE. Circulating levels of EE sulfate range from 6 to 22 times those of EE when EE is taken orally. EE sulfate can be transformed back into EE (14–21%) via steroid sulfatase, and it has been suggested that EE sulfate may serve as a circulating reservoir for EE, similarly to the case of estrone sulfate with estradiol. However, the EE sulfate pool with EE is far smaller than the pool of estrone sulfate that occurs with estradiol. In addition, in contrast to the case of estrone sulfate and estrone, the conversion rate of EE sulfate back into EE is relatively low, and has been said probably isn't of clinical significance. However, other studies have suggested that EE sulfate may nonetheless contribute up to 20% of total EE levels.
Estrone phosphate (E1P), or estrone 3-phosphate, is an estrogen and steroid sulfatase inhibitor which was never marketed. It has similar affinity for steroid sulfatase as estrone sulfate and acts as a competitive inhibitor of the enzyme. In contrast to estrone sulfate however, it is not hydrolyzed by steroid sulfatase and is instead metabolized by phosphatases.
2-Methoxyestradiol disulfamate is a synthetic, oral active anti-cancer medication which was previously under development for potential clinical use. It has improved potency, low metabolism, and good pharmacokinetic properties relative to 2-methoxyestradiol (2-MeO-E2). It is also a potent inhibitor of steroid sulfatase, the enzyme that catalyzes the desulfation of steroids such as estrone sulfate and dehydroepiandrosterone sulfate (DHEA-S).
