Segesterone acetate

Identification

Name
Segesterone acetate
Accession Number
DB14583
Type
Small Molecule
Groups
Approved, Investigational
Description

Segesterone acetate is a steroidal progestin or synthetic progesterone and a 19-norprogesterone derivative with no CH3 group radical in position 6 [1]. In animal studies, segesterone acetate was shown to be one of the most potent progestins [3]. It mediates progestational activity 100 times higher than that of Progesterone [5]. It is commonly sold under the brand names Nestorone and Elcometrine and serves as an active component in hormonal contraceptives. It is also used as a treatment for endometriosis in South American countries. Segesterone acetate binds selectively to progesterone receptors and not androgen receptors [2]. Due to its rapid hepatic metabolism, segesterone acetate must be administered parenterally [3]. Segesterone acetate is not an orally active compound, but it is proved to be a potent anti-ovulatory agent when given in implants, vaginal rings or percutaneous gel [3].

On August 10, 2018, Annovera™ containing segesterone acetate and Ethinylestradiol was granted approval by the U.S. Food and Drug Administration (FDA) as the first and only contraceptive that provides an entire year of protection against unintended pregnancy while entirely under a woman's control. According to the Center for Disease Control, more than 43 million women in the U.S. are at risk of unintended pregnancy, which may be associated with an elevated risk for improper prenatal care, premature and low-birth-weight infants, and physical and mental health risks [8]. The introduction of this new contraceptive method offers an expansion of birth control options for women while maintaining high efficacy and acceptability similar to existing shorter-acting combined hormonal methods [2]. In clinical trials, Annovera™ achieved a 97.3% success in pregnancy prevention [8]. Annovera™ is administered as a vaginal ring that is in place for 21 days and removed for 7 days each cycle. As with other hormonal contraceptives, Annovera™ carries the risk for serious cardiovascular events.

Structure
Thumb
Synonyms
  • 16-Methylene-17-alpha-acetoxy-19-nor-4-pregnene-3,20-dione
  • 17-Hydroxy-16-methylene-19-norpregn-4-ene-3,20-dione acetate
  • Elcometrine
  • Nestorone
External IDs
ST-1435
Categories
UNII
9AMX4Q13CC
CAS number
7759-35-5
Weight
Average: 370.489
Monoisotopic: 370.214409446
Chemical Formula
C23H30O4
InChI Key
CKFBRGLGTWAVLG-GOMYTPFNSA-N
InChI
InChI=1S/C23H30O4/c1-13-11-21-20-7-5-16-12-17(26)6-8-18(16)19(20)9-10-22(21,4)23(13,14(2)24)27-15(3)25/h12,18-21H,1,5-11H2,2-4H3/t18-,19+,20+,21-,22-,23-/m0/s1
IUPAC Name
(1R,3aS,3bR,9aR,9bS,11aS)-1-acetyl-11a-methyl-2-methylidene-7-oxo-1H,2H,3H,3aH,3bH,4H,5H,7H,8H,9H,9aH,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-1-yl acetate
SMILES
[H][C@@]12CC(=C)[C@](OC(C)=O)(C(C)=O)[C@@]1(C)CC[C@]1([H])[C@@]3([H])CCC(=O)C=C3CC[C@@]21[H]

Pharmacology

Indication

Segesterone acetate in combination with ethinyl estradiol is indicated for use by females of reproductive potential to prevent pregnancy as a combination hormonal contraceptive (CHC). It induces contraception for thirteen 28-day cycles (1 year) following vaginal administration. The vaginal system must remain in place continuously for 3 weeks (21 days) followed by a 1-week (7-day) vaginal system-free interval. The use in females with a body mass index of >29 kg/m^2 has not been adequately evaluated [Label].

Associated Therapies
Pharmacodynamics

Segesterone acetate suppresses ovulation. In a Phase I randomized, placebo-controlled, randomized crossover study involving healthy adult female subjects, there was no clinically significant QTc interval prolongation following a single intravenous bolus dose of segesterone acetate [Label]. Segesterone acetate shows no androgenic, anabolic, or estrogenic activity [3]. It also did not show uterotropic activity in ovariectomized rats [3]. In the endometrial transformation test to assess the progestational activity, dose-dependent increases in both uterine weight was observed following subcutaneous administration of segesterone acetate [5].

Mechanism of action

Segesterone acetate selectively binds to the progesterone receptor (PR), a transcription factor belonging to the nuclear receptor superfamily, where it acts as an agonist and transactivator [5]. According to the findings from docking experiments, it adopts the same docking position within the PR ligand-binding domain (LBD) as progesterone but due to additional stabilizing contacts between 17α-acetoxy and 16-methylene groups and PR LBD, segesterone acetate display higher potency than progesterone [5]. As with other progestins, segesterone acetate prevents ovulation by blocking the midcycle surge in luteinizing hormone (LH) secretion, thereby inhibiting the development of ovarian follicles [6]. When used in combination with segesterone acetate, ethinyl estradiol potentiates the antigonadotropic of the progestin and prevents irregular shedding of the endometrium [6]. Segesterone acetate lacks androgenic activity, and displayed binding affinity to androgen receptors that was 500- to 600-fold less than that of testosterone [4]. It does not display binding affinity toward estrogen receptors [4]. When the relative binding affinities of segesterone acetate to human steroid receptors were investigated in vitro, it was demonstrated that segesterone acetate binds to the glucocorticoid receptor [3]. However, segesterone acetate did not exert any glucocorticoid activity in the in vivo assays showing no increase in liver glycogen and tyrosine transaminase TAT [3].

TargetActionsOrganism
AProgesterone receptor
agonist
activator
Human
NAndrogen receptor
agonist
Human
NGlucocorticoid receptor
agonist
Human
Absorption

Contraceptive vaginal rings provided sustained release of contraceptive levels of segesterone acetate over 90 days in a pharmacokinetic study of healthy women [2]. Following vaginal administration for up to 13 cycles, segesterone acetate was absorbed into systemic administration and reached the peak plasma concentration in 2 hours in Cycle 1, Cycle 3, and Cycle 13. Concentrations declined after time to reach plasma concentration (Tmax) and became more constant after 96 hours post-dose.Over subsequent cycles of use, the peak serum concentrations of segesterone acetate decreased. In Cycle 1, 3 and 13, the peak plasma concentrations were 1147, 363, and 294 pg/mL [Label].

Volume of distribution

The volume of distribution of segesterone acetate is 19.6 L/kg [Label].

Protein binding

Serum protein binding of segesterone acetate is approximately 95% and it displays negligible binding affinity for sex hormone-binding globulin (SHBG) [Label].

Metabolism

Segesterone acetate undergoes rapid metabolism and inactivation in the liver [5]. Based on the findings in vitro, the major oxidative metabolites in the serum include 5α-dihydro- and 17α-hydroxy-5α­-dihydro metabolites constitute about 50% of exposure relative to segesterone acetate. The metabolites are not pharmacologically active with EC50 to progesterone receptor 10-fold higher than that of the parent compound [Label]. It was shown that 3α, 5α-tetrahydrosegesterone acetate acts as an activator at the GABA-A receptors in the brain [5].

Route of elimination

In a pharmacokinetic study, approximately 81.4% and 7.62% of the subcutaneously-administered dose in rats was excreted via feces and urine, respectively [Label].

Half life

The mean (SD) half life of segesterone acetate is 4.5 (3.4) hours [Label].

Clearance

No pharmacokinetic data available.

Toxicity

There have been no reports of serious ill effects from overdose of combination hormonal contraceptive use. Overdosage may cause withdrawal bleeding in females and nausea. In case of suspected overdose, all vaginal systems containing segesterone acetate should be removed and symptomatic treatment should be initiated [Label].

In a 2-year carcinogenicity study in rats receiving segesterone acetate via subdermal implants, there was no drug-related increase in tumor incidence. In a 2-year intravaginal carcinogenicity study in mice, segesterone acetate gel produced an increased incidence of adenocarcinoma and lobular hyperplasia in the breast at a supratherapeutic dose of 30 mg/kg/day. Segesterone acetate was not shown to be mutagenic or clastogenic [Label].

Affected organisms
Not Available
Pathways
Not Available
Pharmacogenomic Effects/ADRs
Not Available

Interactions

Drug Interactions
DrugInteraction
AlclometasoneThe serum concentration of Alclometasone can be increased when it is combined with Segesterone acetate.
AlfuzosinThe metabolism of Segesterone acetate can be decreased when combined with Alfuzosin.
AmcinonideThe serum concentration of Amcinonide can be increased when it is combined with Segesterone acetate.
AmitriptylineThe metabolism of Amitriptyline can be decreased when combined with Segesterone acetate.
AmoxicillinThe metabolism of Segesterone acetate can be increased when combined with Amoxicillin.
AnagrelideThe therapeutic efficacy of Anagrelide can be increased when used in combination with Segesterone acetate.
ArgatrobanThe therapeutic efficacy of Argatroban can be increased when used in combination with Segesterone acetate.
AtomoxetineThe metabolism of Segesterone acetate can be decreased when combined with Atomoxetine.
AzithromycinThe metabolism of Segesterone acetate can be decreased when combined with Azithromycin.
BetamethasoneThe metabolism of Segesterone acetate can be increased when combined with Betamethasone.
Food Interactions
Not Available

References

General References
  1. Simmons KB, Kumar N, Plagianos M, Roberts K, Hoskin E, Han L, Alami M, Creasy G, Variano B, Merkatz R: Effects of concurrent vaginal miconazole treatment on the absorption and exposure of Nestorone(R) (segesterone acetate) and ethinyl estradiol delivered from a contraceptive vaginal ring: a randomized, crossover drug-drug interaction study. Contraception. 2018 Mar;97(3):270-276. doi: 10.1016/j.contraception.2017.10.010. Epub 2017 Oct 31. [PubMed:29097225]
  2. Jensen JT, Edelman AB, Chen BA, Archer DF, Barnhart KT, Thomas MA, Burke AE, Westhoff CL, Wan LS, Sitruk-Ware R, Kumar N, Variano B, Blithe DL: Continuous dosing of a novel contraceptive vaginal ring releasing Nestorone(R) and estradiol: pharmacokinetics from a dose-finding study. Contraception. 2018 May;97(5):422-427. doi: 10.1016/j.contraception.2018.01.012. Epub 2018 Feb 2. [PubMed:29409834]
  3. Sitruk-Ware R: Pharmacological profile of progestins. Maturitas. 2008 Sep-Oct;61(1-2):151-7. [PubMed:19434887]
  4. Kumar N, Koide SS, Tsong Y, Sundaram K: Nestorone: a progestin with a unique pharmacological profile. Steroids. 2000 Oct-Nov;65(10-11):629-36. [PubMed:11108869]
  5. Kumar N, Fagart J, Liere P, Mitchell SJ, Knibb AR, Petit-Topin I, Rame M, El-Etr M, Schumacher M, Lambert JJ, Rafestin-Oblin ME, Sitruk-Ware R: Nestorone(R) as a Novel Progestin for Nonoral Contraception: Structure-Activity Relationships and Brain Metabolism Studies. Endocrinology. 2017 Jan 1;158(1):170-182. doi: 10.1210/en.2016-1426. [PubMed:27824503]
  6. Rivera R, Yacobson I, Grimes D: The mechanism of action of hormonal contraceptives and intrauterine contraceptive devices. Am J Obstet Gynecol. 1999 Nov;181(5 Pt 1):1263-9. [PubMed:10561657]
  7. Prasad PV, Bashir M, Sitruk-Ware R, Kumar N: Single-dose pharmacokinetics of Nestorone, a potential female-contraceptive. Steroids. 2010 Mar;75(3):252-64. doi: 10.1016/j.steroids.2009.12.011. Epub 2010 Jan 11. [PubMed:20064539]
  8. FDA Approves Annovera (segesterone acetate and ethinyl estradiol) Vaginal Contraceptive System - Drugs.com [Link]
External Links
ChemSpider
97161
ChEBI
135563
ChEMBL
CHEMBL3707377
Wikipedia
Segesterone_acetate
FDA label
Download (2.18 MB)

Clinical Trials

Clinical Trials
PhaseStatusPurposeConditionsCount
1CompletedDiagnosticContraception1
1CompletedPreventionContraception1
1CompletedTreatmentAntifungal Drug Adverse Reaction1

Pharmacoeconomics

Manufacturers
Not Available
Packagers
Not Available
Dosage forms
Not Available
Prices
Not Available
Patents
Not Available

Properties

State
Solid
Experimental Properties
PropertyValueSource
melting point (°C)173-177FDA Label
water solubilityInsolubleFDA Label
Predicted Properties
PropertyValueSource
Water Solubility0.00231 mg/mLALOGPS
logP2.52ALOGPS
logP3.64ChemAxon
logS-5.2ALOGPS
pKa (Strongest Acidic)17.46ChemAxon
pKa (Strongest Basic)-4.7ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count0ChemAxon
Polar Surface Area60.44 Å2ChemAxon
Rotatable Bond Count3ChemAxon
Refractivity102.95 m3·mol-1ChemAxon
Polarizability41.79 Å3ChemAxon
Number of Rings4ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted ADMET features
Not Available

Spectra

Mass Spec (NIST)
Not Available
Spectra
Not Available

Taxonomy

Classification
Not classified

Targets

Kind
Protein
Organism
Human
Pharmacological action
Yes
Actions
Agonist
Activator
General Function
Zinc ion binding
Specific Function
The steroid hormones and their receptors are involved in the regulation of eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues. Progesterone receptor ...
Gene Name
PGR
Uniprot ID
P06401
Uniprot Name
Progesterone receptor
Molecular Weight
98979.96 Da
References
  1. Kumar N, Fagart J, Liere P, Mitchell SJ, Knibb AR, Petit-Topin I, Rame M, El-Etr M, Schumacher M, Lambert JJ, Rafestin-Oblin ME, Sitruk-Ware R: Nestorone(R) as a Novel Progestin for Nonoral Contraception: Structure-Activity Relationships and Brain Metabolism Studies. Endocrinology. 2017 Jan 1;158(1):170-182. doi: 10.1210/en.2016-1426. [PubMed:27824503]
  2. Sitruk-Ware R: Pharmacological profile of progestins. Maturitas. 2008 Sep-Oct;61(1-2):151-7. [PubMed:19434887]
  3. Kumar N, Koide SS, Tsong Y, Sundaram K: Nestorone: a progestin with a unique pharmacological profile. Steroids. 2000 Oct-Nov;65(10-11):629-36. [PubMed:11108869]
Kind
Protein
Organism
Human
Pharmacological action
No
Actions
Agonist
General Function
Zinc ion binding
Specific Function
Steroid hormone receptors are ligand-activated transcription factors that regulate eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues. Transcription ...
Gene Name
AR
Uniprot ID
P10275
Uniprot Name
Androgen receptor
Molecular Weight
98987.9 Da
References
  1. Kumar N, Koide SS, Tsong Y, Sundaram K: Nestorone: a progestin with a unique pharmacological profile. Steroids. 2000 Oct-Nov;65(10-11):629-36. [PubMed:11108869]
Kind
Protein
Organism
Human
Pharmacological action
No
Actions
Agonist
General Function
Zinc ion binding
Specific Function
Receptor for glucocorticoids (GC). Has a dual mode of action: as a transcription factor that binds to glucocorticoid response elements (GRE), both for nuclear and mitochondrial DNA, and as a modula...
Gene Name
NR3C1
Uniprot ID
P04150
Uniprot Name
Glucocorticoid receptor
Molecular Weight
85658.57 Da
References
  1. Sitruk-Ware R: Pharmacological profile of progestins. Maturitas. 2008 Sep-Oct;61(1-2):151-7. [PubMed:19434887]

Enzymes

Kind
Protein
Organism
Human
Pharmacological action
Unknown
Actions
Substrate
General Function
Vitamin d3 25-hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation react...
Gene Name
CYP3A4
Uniprot ID
P08684
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da

Drug created on August 13, 2018 15:06 / Updated on September 17, 2018 21:07