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Pronunciation | a" bir a' ter one |
Trade names | Zytiga, Yonsa, others |
Other names | CB-7630; JNJ-212082; 17-(3-Pyridinyl)androsta-5,16-dien-3β-ol acetate, abiraterone (BAN UK), abiraterone acetate (JAN JP), abiraterone acetate (USAN US) |
AHFS/Drugs.com | Monograph |
MedlinePlus | a611046 |
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Routes of administration | By mouth [2] [3] |
Drug class | Antineoplastic |
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Pharmacokinetic data | |
Bioavailability | Unknown, but may be 50% at most on empty stomach [6] |
Protein binding | Abiraterone: ~99.8% (to albumin and α1-AGp ) [6] [2] [7] |
Metabolism | Esterases, CYP3A4, SULT2A1 [7] |
Metabolites | Abiraterone, others [2] [6] |
Elimination half-life | Abiraterone: 12–24 hours [2] [6] [3] |
Excretion | Feces: 88% [2] [7] Urine: 5% [2] [7] [3] |
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ECHA InfoCard | 100.149.063 |
Chemical and physical data | |
Formula | C26H33NO2 |
Molar mass | 391.555 g·mol−1 |
3D model (JSmol) | |
Melting point | 144 to 145 °C (291 to 293 °F) [8] |
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Abiraterone acetate, sold under the brand name Zytiga among others, is a medication used to treat prostate cancer. [9] Specifically it is used together with a corticosteroid for metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC). [2] [3] It should either be used following removal of the testicles or along with a gonadotropin-releasing hormone (GnRH) analog. [2] It is taken by mouth. [9]
Common side effects include tiredness, vomiting, headache, joint pain, high blood pressure, swelling, low blood potassium, high blood sugar, hot flashes, diarrhea, and cough. [9] [2] Other severe side effects may include liver failure and adrenocortical insufficiency. [2] In males whose partners can become pregnant, birth control is recommended. [2] Supplied as abiraterone acetate it is converted in the body to abiraterone. [2] Abiraterone acetate works by suppressing the production of androgens – specifically it inhibits CYP17A1 – and thereby decreases the production of testosterone. [9] In doing so, it prevents the effects of these hormones in prostate cancer. [9]
Abiraterone acetate was described in 1995, and approved for medical use in the United States and the European Union in 2011. [10] [2] It is on the World Health Organization's List of Essential Medicines. [11] [12] It is available as a generic medication. [13]
Abiraterone acetate is used in combination with prednisone, a corticosteroid, as a treatment for mCRPC (previously called hormone-resistant or hormone-refractory prostate cancer). [2] [14] [5] [4] This is a form of prostate cancer that is not responding to first-line androgen deprivation therapy or treatment with androgen receptor antagonists. Abiraterone acetate has received Food and Drug Administration (FDA) (28 April 2011), European Medicines Agency (EMA) (23 September 2011), Medicines and Healthcare products Regulatory Agency (MHRA) (5 September 2011) and Therapeutic Goods Administration (TGA) (1 March 2012) approval for this indication. [2] [14] [5] [4] In Australia it is covered by the Pharmaceutical Benefits Scheme when being used to treat castration-resistant prostate cancer and given in combination with prednisone/prednisolone (subject to the conditions that the patient is not currently receiving chemotherapy, is either resistant or intolerant of docetaxel, has a WHO performance status of <2, and his disease has not since become progressive since treatment with PBS-subsidised abiraterone acetate has commenced). [15]
Abiraterone acetate/methylprednisolone, sold under the brand name Yonsa Mpred, is a composite package that contains both abiraterone acetate (Yonsa) and methylprednisolone. [16] It was approved for medical use in Australia in March 2022. [16] [17] [18]
Contraindications include hypersensitivity to abiraterone acetate. Although documents state that it should not be taken by women who are or who may become pregnant, [14] [19] there is no medical reason that any woman should take it. Women who are pregnant should not even touch the pills unless they are wearing gloves. [19] Other cautions include severe baseline hepatic impairment, mineralocorticoid excess, cardiovascular disease including heart failure and hypertension, uncorrected hypokalemia, and adrenocorticoid insufficiency. [20]
Side effects by frequency: [2] [14] [5] [4] [20]
Very common (>10% frequency):
Common (1-10% frequency):
Uncommon (0.1-1% frequency):
Rare (<0.1% frequency):
Experience with overdose of abiraterone acetate is limited. [2] There is no specific antidote for abiraterone acetate overdose, and treatment should consist of general supportive measures, including monitoring of cardiac and liver function. [2]
Abiraterone acetate is a CYP3A4 substrate and hence should not be administered concurrently with strong CYP3A4 inhibitors such as ketoconazole, itraconazole, clarithromycin, atazanavir, nefazodone, saquinavir, telithromycin, ritonavir, indinavir, nelfinavir, voriconazole) or inducers such as phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarbital. [20] [19] It also inhibits CYP1A2, CYP2C9, and CYP3A4 and likewise should not be taken concurrently with substrates of any of these enzymes that have a narrow therapeutic index. [20] [19]
Spironolactone generally exerts anti-androgenic effects, but experimental evidence exists that it acts as an androgen receptor agonist in an androgen-depleted environment, capable of inducing prostate cancer proliferation. [21] This is supported by the observations described in several case reports. [22]
Abiraterone, the active metabolite of abiraterone acetate, inhibits CYP17A1, which manifests as two enzymes, 17α-hydroxylase (IC50 = 2.5 nM) and 17,20-lyase (IC50 = 15 nM) (approximately 6-fold more selective for inhibition of 17α-hydroxylase over 17,20-lyase) [23] [24] that are expressed in testicular, adrenal, and prostatic tumor tissues. CYP17A1 catalyzes two sequential reactions: (a) the conversion of pregnenolone and progesterone to their 17α-hydroxy derivatives by its 17α-hydroxylase activity, and (b) the subsequent formation of dehydroepiandrosterone (DHEA) and androstenedione, respectively, by its 17,20-lyase activity. [25] DHEA and androstenedione are androgens and precursors of testosterone. Inhibition of CYP17A1 activity by abiraterone acetate thus decreases circulating levels of androgens such as DHEA, testosterone, and dihydrotestosterone (DHT). Abiraterone acetate, via abiraterone, has the capacity to lower circulating testosterone levels to less than 1 ng/dL (i.e., undetectable) when added to castration. [23] [26] These concentrations are considerably lower than those achieved by castration alone (~20 ng/dL). [26] The addition of abiraterone acetate to castration was found to reduce levels of DHT by 85%, DHEA by 97 to 98%, and androstenedione by 77 to 78% relative to castration alone. [26] In accordance with its antiandrogenic action, abiraterone acetate decreases the weights of the prostate gland, seminal vesicles, and testes. [27]
Abiraterone also acts as a partial antagonist of the androgen receptor (AR), and as an inhibitor of the enzymes 3β-hydroxysteroid dehydrogenase (3β-HSD), CYP11B1 (steroid 11β-hydroxylase), CYP21A2 (Steroid 21-hydroxylase), and other CYP450s (e.g., CYP1A2, CYP2C9, and CYP3A4). [20] [28] [29] [30] In addition to abiraterone itself, part of the activity of the drug has been found to be due to a more potent active metabolite, δ4-abiraterone (D4A), which is formed from abiraterone by 3β-HSD. [31] D4A is an inhibitor of CYP17A1, 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase, and 5α-reductase, and has also been found to act as a competitive antagonist of the AR reportedly comparable to the potent antagonist enzalutamide. [31] However, the initial 5α-reduced metabolite of D4A, 3-keto-5α-abiraterone, is an agonist of the AR, and promotes prostate cancer progression. [32] Its formation can be blocked by the coadministration of dutasteride, a potent and selective 5α-reductase inhibitor. [32]
There has been interest in the use of abiraterone acetate for the treatment of breast cancer due to its ability to lower estrogen levels. [33] However, abiraterone has been found to act as a direct agonist of the estrogen receptor, and induces proliferation of human breast cancer cells in vitro . [33] If abiraterone acetate is used in the treatment of breast cancer, it should be combined with an estrogen receptor antagonist like fulvestrant. [33] In spite of its antiandrogenic and estrogenic properties, abiraterone acetate does not appear to produce gynecomastia as a side effect. [34]
Due to inhibition of glucocorticoid biosynthesis, abiraterone acetate can cause glucocorticoid deficiency, mineralocorticoid excess, and associated adverse effects. [35] This is why the medication is combined with prednisone, a corticosteroid, which serves as a means of glucocorticoid replacement and prevents mineralocorticoid excess. [36]
Abiraterone acetate, along with galeterone, has been identified as an inhibitor of sulfotransferases (SULT2A1, SULT2B1b, SULT1E1), which are involved in the sulfation of DHEA and other endogenous steroids and compounds, with Ki values in the sub-micromolar range. [37]
After oral administration, abiraterone acetate, the prodrug form in the commercial preparation, is converted into the active form, abiraterone. This conversion is likely to be esterase-mediated and not CYP-mediated. Administration with food increases absorption of the drug and thus has the potential to result in increased and highly variable exposures; the drug should be consumed on an empty stomach at least one hour before or two hours after food. The drug is highly protein bound (>99%), and is metabolized in the liver by CYP3A4 and SULT2A1 to inactive metabolites. The drug is excreted in feces (~88%) and urine (~5%), and has a terminal half-life of 12 ± 5 hours. [19]
Abiraterone acetate, also known as 17-(3-pyridinyl)androsta-5,16-dien-3β-ol acetate, is a synthetic androstane steroid and a derivative of androstadienol (androsta-5,16-dien-3β-ol), an endogenous androstane pheromone. [38] It is specifically a derivative of androstadienol with a pyridine ring attached at the C17 position and an acetate ester attached to the C3β hydroxyl group. [38] Abiraterone acetate is the C3β acetate ester of abiraterone. [38]
In the early 1990s, Mike Jarman, Elaine Barrie, and Gerry Potter of the Cancer Research UK Centre for Cancer Therapeutics in the Institute of Cancer Research in London set out to develop drug treatments for prostate cancer. With the nonsteroidal androgen synthesis inhibitor ketoconazole as a model, they developed abiraterone acetate, filing a patent in 1993 and publishing the first paper describing it the following year. [10] [39] Rights for commercialization of the drug were assigned to BTG, a UK-based specialist healthcare company. BTG then licensed the product to Cougar Biotechnology, which began development of the commercial product. [40] In 2009, Cougar was acquired by Johnson & Johnson, which developed and sells the commercial product, and is conducting ongoing clinical trials to expand its clinical uses. [41]
Abiraterone acetate was approved by the United States Food and Drug Administration on 28 April 2011 for mCRPC. [42] [43] The FDA press release made reference to a phase III clinical trial in which abiraterone acetate use was associated with a median survival of 14.8 months versus 10.9 months with placebo; the study was stopped early because of the successful outcome. [44] Abiraterone acetate was also licensed by the European Medicines Agency. [45] Until May 2012 the National Institute for Health and Clinical Excellence (NICE) did not recommend use of the drug within the NHS on cost-effectiveness grounds. This position was reversed when the manufacturer submitted revised costs. [46] The use is currently limited to men who have already received one docetaxel-containing chemotherapy regimen. [47] [48] It was subsequently approved for the treatment of mCSPC in 2018. [49]
Abiraterone is the INN and BAN of abiraterone acetate's major active metabolite abiraterone. [50] [51] Abiraterone acetate is the USAN , BANM , and JAN of abiraterone acetate. [50] It is also known by its developmental code names CB-7630 and JNJ-212082, while CB-7598 was the developmental code name of abiraterone. [50] [52]
Abiraterone acetate is marketed by Janssen Biotech (a subsidiary of Johnson & Johnson) under the brand name Zytiga, [50] and by Sun Pharmaceutical under the brand name Yonsa. [50]
Generic versions of abiraterone acetate have been approved in the United States. [53] Generic versions of Yonsa are not available as of November 2019 [update] . [54] In May 2019, the United States Court of Appeals for the Federal Circuit upheld a Patent Trial and Appeal Board decision invalidating a patent by Johnson & Johnson on abiraterone acetate. [55]
Intas Pharmaceuticals markets the drug under the brand name Abiratas, Cadila Pharmaceuticals markets the drug as Abretone, and Glenmark Pharmaceuticals as Abirapro.[ citation needed ] It is marketed as Yonsa by Sun Pharmaceutical Industries (licensed from Churchill Pharmaceuticals). [56] [57]
Abiraterone acetate is marketed widely throughout the world, including in the United States, Canada, the United Kingdom, Ireland, elsewhere in Europe, Australia, New Zealand, Latin America, Asia, and Israel. [50]
A generic version is available in India at a price of $238 a month as of 2019 [update] . [58] The National Centre for Pharmacoeconomics initially found abiraterone acetate to not be cost effective based on prices in 2012, however following an agreement to supply at a lower price it was accepted in 2014. [58] [59] A generic Zytiga version is available in India at a price of under $230 a month as of 2020. [60]
Abiraterone acetate is under development for the treatment of breast cancer and ovarian cancer and as of March 2018, is in phase II clinical trials for these indications. [52] It was also under investigation for the treatment of congenital adrenal hyperplasia, but no further development has been reported for this potential use. [52]
In people previously treated with docetaxel survival is increased by 3.9 months (14.8 months versus 10.9 months for placebo). [61]
In people with castration-refractory prostate cancer but who had not received chemotherapy those who received abiraterone acetate had a progression-free survival of 16.5 months rather than 8.3 months with placebo. After a median follow-up period of 22.2 months, overall survival was better with abiraterone acetate. [62]
Abiraterone acetate may be useful for prevention of the testosterone flare at the initiation of GnRH agonist therapy in men with prostate cancer. [63]
Antiandrogens, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the androgen receptor (AR) and/or inhibiting or suppressing androgen production. They can be thought of as the functional opposites of AR agonists, for instance androgens and anabolic steroids (AAS) like testosterone, DHT, and nandrolone and selective androgen receptor modulators (SARMs) like enobosarm. Antiandrogens are one of three types of sex hormone antagonists, the others being antiestrogens and antiprogestogens.
Bicalutamide, sold under the brand name Casodex among others, is an antiandrogen medication that is primarily used to treat prostate cancer. It is typically used together with a gonadotropin-releasing hormone (GnRH) analogue or surgical removal of the testicles to treat metastatic prostate cancer (mPC). To a lesser extent, it is used at high doses for locally advanced prostate cancer (LAPC) as a monotherapy without castration. Bicalutamide was also previously used as monotherapy to treat localized prostate cancer (LPC), but authorization for this use was withdrawn following unfavorable trial findings. Besides prostate cancer, bicalutamide is limitedly used in the treatment of excessive hair growth and scalp hair loss in women, as a puberty blocker and component of feminizing hormone therapy for transgender girls and women, to treat gonadotropin-independent early puberty in boys, and to prevent overly long-lasting erections in men. It is taken by mouth.
Cytochrome P450 17A1 is an enzyme of the hydroxylase type that in humans is encoded by the CYP17A1 gene on chromosome 10. It is ubiquitously expressed in many tissues and cell types, including the zona reticularis and zona fasciculata of the adrenal cortex as well as gonadal tissues. It has both 17α-hydroxylase and 17,20-lyase activities, and is a key enzyme in the steroidogenic pathway that produces progestins, mineralocorticoids, glucocorticoids, androgens, and estrogens. More specifically, the enzyme acts upon pregnenolone and progesterone to add a hydroxyl (-OH) group at carbon 17 position (C17) of the steroid D ring, or acts upon 17α-hydroxyprogesterone and 17α-hydroxypregnenolone to split the side-chain off the steroid nucleus.
Enzalutamide, sold under the brand name Xtandi, is a nonsteroidal antiandrogen (NSAA) medication which is used in the treatment of prostate cancer. It is indicated for use in conjunction with castration in the treatment of metastatic castration-resistant prostate cancer (mCRPC), nonmetastatic castration-resistant prostate cancer, and metastatic castration-sensitive prostate cancer (mCSPC). It is taken by mouth.
Veliparib (ABT-888) is a potential anti-cancer drug acting as a PARP inhibitor. It kills cancer cells by blocking a protein called PARP, thereby preventing the repair of DNA or genetic damage in cancer cells and possibly making them more susceptible to anticancer treatments. Veliparib may make whole brain radiation treatment work more effectively against brain metastases from NSCLC. It has been shown to potentiate the effects of many chemotherapeutics, and as such has been part of many combination clinical trials.
Cabazitaxel, sold under the brand name Jevtana, is a semi-synthetic derivative of a natural taxoid. It is a microtubule inhibitor, and the fourth taxane to be approved as a cancer therapy.
Orteronel (TAK-700) is a nonsteroidal CYP17A1 inhibitor that was being developed for the treatment of cancer by Takeda Pharmaceutical Company in conjunction with Millennium Pharmaceuticals. It completed two phase III clinical trials for metastatic, hormone-refractory prostate cancer but failed to extend overall survival rates, and development was voluntarily terminated as a result.
Galeterone is a steroidal antiandrogen which was under development by Tokai Pharmaceuticals for the treatment of prostate cancer. It possesses a unique triple mechanism of action, acting as an androgen receptor antagonist, androgen receptor down regulator, and CYP17A1 inhibitor, the latter of which prevents the biosynthesis of androgens. As a CYP17A1 inhibitor, galeterone shows selectivity for 17,20-lyase over 17α-hydroxylase.
Isolated 17,20-lyase deficiency (ILD), also called isolated 17,20-desmolase deficiency, is a rare endocrine and autosomal recessive genetic disorder which is characterized by a complete or partial loss of 17,20-lyase activity and, in turn, impaired production of the androgen and estrogen sex steroids. The condition manifests itself as pseudohermaphroditism in males, in whom it is considered to be a form of intersex, and, in both sexes, as a reduced or absent puberty/lack of development of secondary sexual characteristics, resulting in a somewhat childlike appearance in adulthood.
Seviteronel is an experimental cancer medication which is under development by Viamet Pharmaceuticals and Innocrin Pharmaceuticals for the treatment of prostate cancer and breast cancer. It is a nonsteroidal CYP17A1 inhibitor and works by inhibiting the production of androgens and estrogens in the body. As of July 2017, seviteronel is in phase II clinical trials for both prostate cancer and breast cancer. In January 2016, it was designated fast-track status by the United States Food and Drug Administration for prostate cancer. In April 2017, seviteronel received fast-track designation for breast cancer as well.
Apalutamide, sold under the brand name Erleada among others, is a nonsteroidal antiandrogen (NSAA) medication which is used in the treatment of prostate cancer. It is specifically indicated for use in conjunction with castration in the treatment of non-metastatic castration-resistant prostate cancer (NM-CRPC). It is taken by mouth.
Ralaniten acetate is a first-in-class antiandrogen that targets the N-terminal domain (NTD) of the androgen receptor (AR) developed by ESSA Pharmaceuticals and was under investigation for the treatment of prostate cancer. This mechanism of action is believed to allow the drug to block signaling from the AR and its splice variants. EPI-506 is a derivative of bisphenol A and a prodrug of ralaniten (EPI-002), one of the four stereoisomers of EPI-001, and was developed as a successor of EPI-001. The drug reached phase I/II prior to the discontinuation of its development. It showed signs of efficacy in the form of prostatic specific antigen (PSA) decreases (4–29%) predominantly at higher doses (≥1,280 mg) in some patients but also caused side effects and was discontinued by its developer in favor of next-generation AR NTD inhibitors with improved potency and tolerability.
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.
A steroidal antiandrogen (SAA) is an antiandrogen with a steroidal chemical structure. They are typically antagonists of the androgen receptor (AR) and act both by blocking the effects of androgens like testosterone and dihydrotestosterone (DHT) and by suppressing gonadal androgen production. SAAs lower concentrations of testosterone through simulation of the negative feedback inhibition of the hypothalamus. SAAs are used in the treatment of androgen-dependent conditions in men and women, and are also used in veterinary medicine for the same purpose. They are the converse of nonsteroidal antiandrogens (NSAAs), which are antiandrogens that are not steroids and are structurally unrelated to testosterone.
A CYP17A1 inhibitor is a type of drug which inhibits the enzyme CYP17A1. It may inhibit both of the functions of the enzyme, 17α-hydroxylase and 17,20-lyase, or may be selective for inhibition of one of these two functions. These drugs prevent the conversion of pregnane steroids into androgens like testosterone and therefore are androgen biosynthesis inhibitors and functional antiandrogens. Examples of CYP17A1 inhibitors include the older drug ketoconazole and the newer drugs abiraterone acetate, orteronel, galeterone, and seviteronel. The CYP17A1 inhibitors that have been marketed, like abiraterone acetate, are used mainly in the treatment of prostate cancer. CYP17A1 inhibitors that are not selective for inhibition of 17,20-lyase must be combined with a glucocorticoid such as prednisone in order to avoid adrenal insufficiency and mineralocorticoid excess caused by prevention of cortisol production.
An androgen synthesis inhibitor is a type of drug which inhibits the enzymatic synthesis of androgens, such as testosterone and dihydrotestosterone (DHT). They include:
Δ4-Abiraterone, also known as 17-(3-pyridyl)androsta-4,16-dien-3-one, is a steroidogenesis inhibitor and active metabolite of abiraterone acetate, a drug which is used in the treatment of prostate cancer and is itself a prodrug of abiraterone. D4A is formed from abiraterone by 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase (3β-HSD). It is said to be a more potent inhibitor of steroidogenesis than abiraterone, and is partially responsible for the activity of abiraterone acetate.
N-Desmethylenzalutamide is a nonsteroidal antiandrogen (NSAA) and the major metabolite of enzalutamide, an NSAA which is used as a hormonal antineoplastic agent in the treatment of metastatic prostate cancer. It has similar activity to that of enzalutamide and, with enzalutamide therapy, circulates at similar concentrations to those of enzalutamide at steady state. N-Desmethylenzalutamide is formed from enzalutamide in the liver by the cytochrome P450 enzymes CYP2C8 and CYP3A4. It has a longer terminal half-life than enzalutamide.
Lutetium (177Lu) vipivotide tetraxetan, sold under the brand name Pluvicto, is a radiopharmaceutical medication used for the treatment of prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC). Lutetium (177Lu) vipivotide tetraxetan is a targeted radioligand therapy.
Niraparib/abiraterone acetate, sold under the brand name Akeega, is a fixed-dose combination anti-cancer medication used for the treatment of prostate cancer. It contains niraparib, a poly (ADP-ribose) polymerase (PARP) inhibitor, and abiraterone acetate, a CYP17 inhibitor.
Abiraterone acetate is a prodrug for abiraterone, a CYP17 inhibitor, which has the capacity to lower serum testosterone levels to less than 1 ng/dL (compared with levels closer to 20 ng/dL that are achieved with conventional ADT).19 [...] Relative to LHRHa alone, the addition of abiraterone resulted in an 85% decline in dihydrotestosterone (DHT) levels, a 97% to 98% decline in dehydroepiandrosterone (DHEA) levels, and a 77% to 78% decline in androstenedione levels.