Galeterone

Last updated
Galeterone
Galeterone.svg
Clinical data
Other namesTOK-001; VN/124-1; 17-(1H-Benzimidazol-1-yl)androsta-5,16-dien-3β-ol
Routes of
administration
By mouth
Identifiers
  • (3S,8R,9S,10R,13S,14S)-17-(benzimidazol-1-yl)-10,13-dimethyl-2,3,4,7,8,9,11,12,14,15-decahydro-1H-cyclopenta[a]phenanthren-3-ol
CAS Number
PubChem CID
ChemSpider
UNII
KEGG
ECHA InfoCard 100.233.599 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C26H32N2O
Molar mass 388.555 g·mol−1
3D model (JSmol)
  • C[C@]12CC[C@@H](CC1=CC[C@@H]3[C@@H]2CC[C@]4([C@H]3CC=C4N5C=NC6=CC=CC=C65)C)O
  • InChI=1S/C26H32N2O/c1-25-13-11-18(29)15-17(25)7-8-19-20-9-10-24(26(20,2)14-12-21(19)25)28-16-27-22-5-3-4-6-23(22)28/h3-7,10,16,18-21,29H,8-9,11-15H2,1-2H3/t18-,19-,20-,21-,25-,26-/m0/s1
  • Key:PAFKTGFSEFKSQG-PAASFTFBSA-N

Galeterone (developmental code names TOK-001, VN/124-1) is a steroidal antiandrogen which was under development by Tokai Pharmaceuticals for the treatment of prostate cancer. [1] It possesses a unique triple mechanism of action, acting as an androgen receptor antagonist, androgen receptor down regulator, [2] and CYP17A1 inhibitor, [3] the latter of which prevents the biosynthesis of androgens. [4] As a CYP17A1 inhibitor, galeterone shows selectivity for 17,20-lyase over 17α-hydroxylase. [5]

Galeterone was being compared to enzalutamide in a phase III clinical trial (ARMOR3-SV) for AR-V7-expressing metastatic castration-resistant prostate cancer. [6] [7] Tokai announced the discontinuation of ARMOR3-SV on July 26, 2016, after a data monitoring committee determined that the trial was unlikely to meet its endpoint. [8] On August 22, 2016, the company announced the discontinuation of their phase II expansion (ARMOR2) as well. [9]

In the week following cancellation of the ARMOR3-SV clinical trial, Tokai announced a reduction of its workforce by around 60% to a total of 10 "full-time equivalent employees." [10] On December 22, 2016, a definitive share purchase agreement was announced, under which shareholders of Otic Pharma Ltd. would become the majority owners of Tokai Pharmaceuticals Inc., resulting in a NASDAQ-listed company (OticPharma, Inc.) focused on the development and commercialization of products for ear, nose, and throat disorders. [11]

In August 2017, Tokai Pharmaceuticals discontinued the development of galeterone. [1] On December 17, 2018, it was announced that Educational & Scientific, LLC (ESL), in conjunction with University of Maryland ventures, would develop the drug. [12] [13] [14]

Prostate cancer drug abiraterone and its analog Galeterone are Δ5,3β-hydroxy steroids. Structures of these two agents are identical to endogenous steroid substrates (cholesterole, dehydroepiandorosterone and pregnenolone) for the 3β-hydroxysteroid dehydrogenase (3βHSD) of endocrine system. It has been reported that both of these agents are metabolized to 3-oxo-Δ4-steroids by 3βHSD in short period on oral administration. First metabolite 3-oxo-Δ4-abiraterone has more potent anti-prostate cancer properties than abiraterone where galeterone metabolite (3-oxo-Δ4-galaterone) has activity comparable to parent. Further these two metabolites undergo metabolism by 5α-reductase (5α-SRD) of endocrine system which leads to five more biologically inactive metabolites (Ref: Cell Chem. Biol. 2017, 24(7), 825; DOI: 10.1016/j.chembiol.2017.05.020). It is known that galeterone has poor oral bioavailability in rodents. Poor pharmacokinetic properties (oral absorption and metabolic half-life) of galeterone may be the reason for its clinical compromise.

Galeterone, along with abiraterone acetate, has been identified as an inhibitor of sulfotransferases (SULT2A1, SULT2B1b, SULT1E1), which are involved in the sulfation of dehydroepiandrosterone and other steroids and compounds, with Ki values in the sub-micromolar range. [15]

Related Research Articles

<span class="mw-page-title-main">Antiandrogen</span> Class of pharmaceutical drugs

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.

<span class="mw-page-title-main">Bicalutamide</span> Prostate cancer treatment

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.

<span class="mw-page-title-main">CYP17A1</span> Mammalian protein found in Homo sapiens

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.

<span class="mw-page-title-main">Trilostane</span> Chemical compound

Trilostane, sold under the brand names Modrenal and Vetoryl among others, is a medication which has been used in the treatment of Cushing's syndrome, Conn's syndrome, and postmenopausal breast cancer in humans. It was withdrawn for use in humans in the United States in the 1990s but was subsequently approved for use in veterinary medicine in the 2000s to treat Cushing's syndrome in dogs. It is taken by mouth.

<span class="mw-page-title-main">Abiraterone acetate</span> Chemical compound

Abiraterone acetate, sold under the brand name Zytiga among others, is a medication used to treat prostate cancer. Specifically it is used together with a corticosteroid for metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC). It should either be used following removal of the testicles or along with a gonadotropin-releasing hormone (GnRH) analog. It is taken by mouth.

<span class="mw-page-title-main">Enzalutamide</span> Antiandrogen medication used in treatment of prostate cancer

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.

<span class="mw-page-title-main">Cabazitaxel</span> Chemical compound

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.

<span class="mw-page-title-main">Inborn errors of steroid metabolism</span> Medical condition

An inborn error of steroid metabolism is an inborn error of metabolism due to defects in steroid metabolism.

<span class="mw-page-title-main">Zanoterone</span> Chemical compound

Zanoterone, also known as (5α,17α)-1'-(methylsulfonyl)-1'-H-pregn-20-yno[3,2-c]pyrazol-17-ol, is a steroidal antiandrogen which was never marketed. It was investigated for the treatment of benign prostatic hyperplasia (BPH) but failed to demonstrate sufficient efficacy in phase II clinical trials, and also showed an unacceptable incidence rate and severity of side effects. As such, it was not further developed.

<span class="mw-page-title-main">Seviteronel</span> Chemical compound

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.

Darolutamide, sold under the brand name Nubeqa, is an antiandrogen medication which is used in the treatment of non-metastatic castration-resistant prostate cancer in men. It is specifically approved to treat non-metastatic castration-resistant prostate cancer (nmCRPC) in conjunction with surgical or medical castration. The medication is taken by mouth twice per day with food.

<span class="mw-page-title-main">Apalutamide</span> Chemical compound

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.

<span class="mw-page-title-main">Ralaniten acetate</span> Chemical compound

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.

<span class="mw-page-title-main">CYP17A1 inhibitor</span>

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.

<span class="mw-page-title-main">Proxalutamide</span> Chemical compound

Proxalutamide is a nonsteroidal antiandrogen (NSAA) – specifically, a selective high-affinity silent antagonist of the androgen receptor (AR) – which is under development by Suzhou Kintor Pharmaceuticals, inc., a subsidiary of Kintor Pharmaceutical Limited, for the potential treatment of COVID-19, prostate cancer, and breast cancer. It was approved in Paraguay for the treatment of COVID-19 in July 2021, but has not been approved at this time in other countries.

Δ<sup>4</sup>-Abiraterone Chemical compound

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.

<span class="mw-page-title-main">3-Keto-5α-abiraterone</span> Chemical compound

3-Keto-5α-abiraterone, also known as 17-(3-pyridyl)-5α-androst-16-en-3-one, is an active metabolite of abiraterone acetate that has been found to possess androgenic activity and to stimulate prostate cancer progression. It is formed as follows: abiraterone acetate to abiraterone by esterases; abiraterone to Δ4-abiraterone by 3β-hydroxysteroid dehydrogenase/Δ5-4 isomerase; and Δ4-abiraterone to 3-keto-5α-abiraterone by 5α-reductase. 3-Keto-5α-abiraterone may counteract the clinical effectiveness of abiraterone acetate, and so inhibition of its formation using the 5α-reductase inhibitor dutasteride is being investigated as an adjunct to abiraterone acetate in the treatment of prostate cancer.

Ketodarolutamide is a nonsteroidal antiandrogen (NSAA) and the major active metabolite of darolutamide, an NSAA which is used in the treatment of prostate cancer in men. Similarly to its parent compound, ketodarolutamide acts as a highly selective, high-affinity, competitive silent antagonist of the androgen receptor (AR). Both agents show much higher affinity and more potent inhibition of the AR relative to the other NSAAs enzalutamide and apalutamide, although they also possess much shorter and comparatively less favorable elimination half-lives. They have also been found not to activate certain mutant AR variants that enzalutamide and apalutamide do activate. Both darolutamide and ketodarolutamide show limited central nervous system distribution, indicating peripheral selectivity, and little or no inhibition or induction of cytochrome P450 enzymes such as CYP3A4, unlike enzalutamide and apalutamide.

References

  1. 1 2 "Galeterone - Eledon Pharmaceuticals - AdisInsight".
  2. Vasaitis, Tadas; Belosay, Aashvini; Schayowitz, Adam; Khandelwal, Aakanksha; Chopra, Pankaj; Gediya, Lalji K.; Guo, Zhiyong; Fang, Hong-Bin; Njar, Vincent C. O.; Brodie, Angela M. H. (August 2008). "Androgen Receptor Inactivation Contributes to Antitumor Efficacy of CYP17 Inhibitor VN/124-1 in Prostate Cancer". Molecular Cancer Therapeutics. 7 (8): 2348–2357. doi:10.1158/1535-7163.MCT-08-0230. ISSN   1535-7163. PMC   2643345 . PMID   18723482.
  3. Handratta, Venkatesh D.; Vasaitis, Tadas S.; Njar, Vincent C. O.; Gediya, Lalji K.; Kataria, Ritesh; Chopra, Pankaj; Newman, Donnell; Farquhar, Rena; Guo, Zhiyong; Qiu, Yun; Brodie, Angela M. H. (2005-04-01). "Novel C-17-Heteroaryl Steroidal CYP17 Inhibitors/Antiandrogens: Synthesis, in Vitro Biological Activity, Pharmacokinetics, and Antitumor Activity in the LAPC4 Human Prostate Cancer Xenograft Model". Journal of Medicinal Chemistry. 48 (8): 2972–2984. doi:10.1021/jm040202w. ISSN   0022-2623. PMID   15828836.
  4. Brawer MK (2008). "New treatments for castration-resistant prostate cancer: highlights from the 44th annual meeting of the American Society of Clinical Oncology, May 30–June 3, 2008, Chicago, IL". Rev Urol. 10 (4): 294–6. PMC   2615106 . PMID   19145273.
  5. Yin L, Hu Q (2014). "CYP17 inhibitors--abiraterone, C17,20-lyase inhibitors and multi-targeting agents". Nat Rev Urol. 11 (1): 32–42. doi:10.1038/nrurol.2013.274. PMID   24276076. S2CID   7131777.
  6. "A Study of Galeterone Compared to Enzalutamide In Men Expressing Androgen Receptor Splice Variant-7 mRNA (AR-V7) Metastatic CRPC - Full Text View - ClinicalTrials.gov". clinicaltrials.gov. Retrieved 2016-02-27.
  7. Silberstein, John L.; Taylor, Maritza N.; Antonarakis, Emmanuel S. (2016-04-01). "Novel Insights into Molecular Indicators of Response and Resistance to Modern Androgen-Axis Therapies in Prostate Cancer". Current Urology Reports. 17 (4): 29. doi:10.1007/s11934-016-0584-4. ISSN   1534-6285. PMC   4888068 . PMID   26902623.
  8. "Tokai Pharmaceuticals Announces Clinical Update" (Press release). 26 July 2016.
  9. "Tokai Pharma in flux with lead product candidate galeterone, enrollment in mid-stage prostate cancer study nixed; shares slump 23% after hours (NASDAQ:ELDN) | Seeking Alpha". 22 August 2016.
  10. "Tokai Pharmaceuticals takes ax to 60% of workforce after PhIII blowout". Fierce Biotech. August 2016.
  11. "Otic Pharma to Become Majority Owner of Tokai Pharma (TKAI)".
  12. "Lowe inks new deal for clinical trials of another cancer drug". Stock Gitter.
  13. "EDUCATIONAL & SCIENTIFIC, LLC AND UNIVERSITY OF MARYLAND, BALTIMORE EXPAND RELATIONSHIP THROUGH LICENSING AGREEMENT TO DEVELOP NOVEL PROSTATE CANCER TREATMENT". BioSpace. Retrieved 2019-04-03.
  14. "Jamaica Observer: Lowe and Team Granted Licence for Further Development of Prostate Cancer Drug". www.umventures.org. Retrieved 2019-04-03.
  15. Yip CK, Bansal S, Wong SY, Lau AJ (February 2018). "Identification of Galeterone and Abiraterone as Inhibitors of Dehydroepiandrosterone Sulfonation Catalyzed by Human Hepatic Cytosol, SULT2A1, SULT2B1b, and SULT1E1". Drug Metab. Dispos. 46 (4): 470–482. doi: 10.1124/dmd.117.078980 . PMID   29436390.