Enzalutamide, sold under the brand name Xtandi, is a

nonsteroidal antiandrogen A nonsteroidal antiandrogen (NSAA) is an antiandrogen with a nonsteroidal chemical structure. They are typically selective and full or silent antagonists of the androgen receptor (AR) and act by directly blocking the effects of androgens lik ...

(NSAA) medication which is used in the treatment of

prostate cancer Prostate cancer is the neoplasm, uncontrolled growth of cells in the prostate, a gland in the male reproductive system below the bladder. Abnormal growth of the prostate tissue is usually detected through Screening (medicine), screening tests, ...

. It is indicated for use in conjunction with

castration Castration is any action, surgery, surgical, chemical substance, chemical, or otherwise, by which a male loses use of the testicles: the male gonad. Surgical castration is bilateral orchiectomy (excision of both testicles), while chemical cas ...

in the treatment of

metastatic Metastasis is a pathogenic agent's spreading from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, ...

castration-resistant prostate cancer Prostate cancer is the uncontrolled growth of cells in the prostate, a gland in the male reproductive system below the bladder. Abnormal growth of the prostate tissue is usually detected through screening tests, typically blood tests that che ...

(mCRPC), nonmetastatic castration-resistant prostate cancer, and metastatic castration-sensitive prostate cancer (mCSPC). It is taken

by mouth Oral administration is a route of administration whereby a substance is taken through the Human mouth, mouth, swallowed, and then processed via the digestive system. This is a common route of administration for many medications. Oral administ ...

Side effect In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually use ...

s of enzalutamide when added to castration include

asthenia Weakness is a symptom of many different medical conditions. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, ...

back pain Back pain (Latin: ''dorsalgia'') is pain felt in the back. It may be classified as neck pain (cervical), middle back pain (thoracic), lower back pain (lumbar) or coccydynia (tailbone or sacral pain) based on the segment affected. The lumbar area ...

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

arthralgia Arthralgia () literally means ' joint pain'. Specifically, arthralgia is a symptom of injury, infection, illness (in particular arthritis), or an allergic reaction to medication Medication (also called medicament, medicine, pharmaceuti ...

, and

hot flash Hot flushes are a form of flushing, often caused by the changing hormone levels that are characteristic of menopause. They are typically experienced as a feeling of intense heat with sweating and rapid heartbeat, and may typically last from t ...

es. Rarely, it can cause

seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

s. It has a high potential for

drug interaction In pharmaceutical sciences, drug interactions occur when a drug's mechanism of action is affected by the concomitant administration of substances such as foods, beverages, or other drugs. A popular example of drug–food interaction is the effect ...

s. Enzalutamide is an

antiandrogen 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 t ...

, and acts as an

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...

, the

biological target A biological target is anything within a living organism to which some other entity (like an endogenous ligand or a drug) is directed and/or binds, resulting in a change in its behavior or function. Examples of common classes of biological targets ...

androgen An androgen (from Greek ''andr-'', the stem of the word meaning ) is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This includes ...

s like

testosterone Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...

and

dihydrotestosterone Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone primarily involved in the growth and repair of the prostate and the penis, as well as the production o ...

. In doing so, it prevents the effects of these

hormone A hormone (from the Ancient Greek, Greek participle , "setting in motion") is a class of cell signaling, signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physio ...

s in the

prostate gland The prostate is an male accessory gland, accessory gland of the male reproductive system and a muscle-driven mechanical switch between urination and ejaculation. It is found in all male mammals. It differs between species anatomically, chemica ...

and elsewhere in the body. Enzalutamide was first described in 2006, and was introduced for the treatment of prostate cancer in 2012. It was the first second-generation NSAA to be introduced. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

Medical uses

Enzalutamide is

indicated In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...

for the treatment of people with castration-resistant prostate cancer; metastatic castration-sensitive prostate cancer; and non‑metastatic castration‑sensitive prostate cancer with biochemical recurrence at high risk for metastasis.

Prostate cancer

There is good evidence that enzalutamide is an effective treatment for increasing overall survival among people with high-risk non-metastatic castration-resistant prostate cancer, particularly those with a PSA doubling time ≤ 6 months.

Other uses

Enzalutamide can be used as an antiandrogen in

feminizing hormone therapy Feminizing hormone therapy, also known as transfeminine hormone therapy, is a form of Transgender_health_care#Gender-affirming_care , gender-affirming care and a gender-affirming hormone therapy , gender-affirming hormone therapy to change t ...

for

transgender women A trans woman or transgender woman is a woman who was assigned male at birth. Trans women have a female gender identity and may experience gender dysphoria (distress brought upon by the discrepancy between a person's gender identity and their ...

Available forms

Enzalutamide is provided as a capsule or tablet.

Contraindications

Enzalutamide is

contraindicated In medicine, a contraindication is a condition (a situation or factor) that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a rea ...

in women during

pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...

. It may cause fetal harm.

Side effects

Notable

side effect In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually use ...

s of enzalutamide seen in

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human subject research, human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel v ...

s have included

gynecomastia Gynecomastia (also spelled gynaecomastia) is the non-cancerous enlargement of one or both breasts in men due to the growth of breast tissue as a result of a hormone imbalance between estrogens and androgens. Updated by Brent Wisse (10 Novemb ...

, breast pain/tenderness,

fatigue Fatigue is a state of tiredness (which is not sleepiness), exhaustion or loss of energy. It is a signs and symptoms, symptom of any of various diseases; it is not a disease in itself. Fatigue (in the medical sense) is sometimes associated wit ...

es,

headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

sexual dysfunction Sexual dysfunction is difficulty experienced by an individual or partners during any stage of normal sexual activity, including physical pleasure, desire, preference, arousal, or orgasm. The World Health Organization defines sexual dysfunction ...

, and, less commonly,

s. Other "common" side effects reported in clinical trials have included

neutropenia Neutropenia is an abnormally low concentration of neutrophils (a type of white blood cell) in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria ...

visual hallucination A visual hallucination is a vivid visual experience occurring without corresponding external stimuli in an awake state. These experiences are involuntary and possess a degree of perceived reality sufficient to resemble authentic visual perception. ...

anxiety Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...

cognitive disorder Neurocognitive disorders (NCDs), also known as cognitive disorders (CDs), are a category of mental health disorders that primarily affect cognitive abilities including learning, memory, perception, and problem-solving. Neurocognitive disorders in ...

memory impairment Amnesia is a deficit in memory caused by brain damage or brain diseases,Gazzaniga, M., Ivry, R., & Mangun, G. (2009) Cognitive Neuroscience: The biology of the mind. New York: W.W. Norton & Company. but it can also be temporarily caused by t ...

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

dry skin Xeroderma, xerosis or xerosis cutis, or simply dry skin, is a skin condition characterized by excessively dry skin. The term derives . In most cases, dry skin can safely be treated with moisturizers (also called emollients). Xeroderma occurs ...

, and

pruritus An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both ...

(itching). Enzalutamide monotherapy is regarded as having a moderate negative effect on sexual function and activity, significantly less than that of GnRH analogues but similar to that of other NSAAs such as bicalutamide.

Central adverse effects

Seizures have occurred in approximately 1% of patients treated with enzalutamide in clinical trials. This is thought to be due to enzalutamide crossing the

blood–brain barrier The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that regulates the transfer of solutes and chemicals between the circulatory system and the central nervous system ...

and exerting off-target binding to and inhibition of the GABA_A receptor in the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

(it has been found to inhibit the GABA_A receptor ''

in vitro ''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

'' ( = 3.6 μM) and induces

convulsion A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is often used as a synony ...

s in animals at high doses). In addition to seizures, other potentially GABA_A receptor-related side effects observed with enzalutamide treatment in clinical trials have included

insomnia Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low ene ...

vertigo Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...

paresthesia Paresthesia is a sensation of the skin that may feel like numbness (''hypoesthesia''), tingling, pricking, chilling, or burning. It can be temporary or Chronic condition, chronic and has many possible underlying causes. Paresthesia is usually p ...

, and headache. Due to its ability to lower the

seizure threshold The term seizure threshold is used to describe the balance between excitatory (glutaminergic) and inhibitory (GABA-ergic) forces in the brain which affect how susceptible a person is to seizures. Those diagnosed with epilepsy or certain other neuro ...

, patients with known

seizure disorder Epilepsy is a group of non-communicable neurological disorders characterized by a tendency for recurrent, unprovoked seizures. A seizure is a sudden burst of abnormal electrical activity in the brain that can cause a variety of symptoms, rang ...

s or

brain injury Brain injury (BI) is the destruction or degeneration of brain cells. Brain injuries occur due to a wide range of internal and external factors. In general, brain damage refers to significant, undiscriminating trauma-induced damage. A common ...

should be closely monitored during enzalutamide treatment. NSAA-induced seizures are responsive to

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), colloquially known as "benzos", are a class of central nervous system (CNS) depressant, depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed t ...

treatment, and it has been suggested that GABA_A receptor inhibition by enzalutamide could be treated with these drugs. In dose-ranging studies, severe

was observed with enzalutamide at doses of 240 mg/day and above.

Rare adverse reactions

There is a single

case report In medicine, a case report is a detailed report of the symptoms, signs, diagnosis, treatment, and follow-up of an individual patient. Case reports may contain a demographic profile of the patient, but usually describe an unusual or novel occurrenc ...

of posterior reversible encephalopathy syndrome (PRES) with enzalutamide treatment. The

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical Drug interaction, interaction through which a Medication, drug substance produces its pharmacological effect. A mechanism of action usually includes mention o ...

of the side effect is unknown, but it was proposed to a consequence of inhibition of the GABA_A receptor by enzalutamide.

Overdose

Enzalutamide may cause

s in

overdose A drug overdose (overdose or OD) is the ingestion or application of a drug or other substance in quantities much greater than are recommended. Retrieved on September 20, 2014.

Interactions

Enzalutamide is a moderate to strong inducer of multiple

cytochrome P450 Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for examp ...

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

s including

CYP3A4 Cytochrome P450 3A4 (abbreviated CYP3A4) () is an important enzyme in the body, mainly found in the liver and in the intestine, which in humans is encoded by ''CYP3A4'' gene. It organic redox reaction, oxidizes small foreign organic molecules ( ...

CYP2C9 Cytochrome P450 family 2 subfamily C member 9 (abbreviated CYP2C9) is an enzyme protein. The enzyme is involved in the metabolism, by oxidation, of both xenobiotics, including drugs, and endogenous compounds, including fatty acids. In humans, t ...

, and

CYP2C19 Cytochrome P450 2C19 (abbreviated CYP2C19) is an enzyme protein. It is a member of the CYP2C subfamily of the cytochrome P450 mixed-function oxidase system. This subfamily includes enzymes that catalyze metabolism of xenobiotics, including some ...

and hence has a high potential for clinically relevant

s. Circulating concentrations of enzalutamide may be altered by

inhibitor Inhibitor or inhibition may refer to: Biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotransmi ...

s and

inducer In molecular biology, an inducer is a molecule that regulates gene expression. An inducer functions in two ways; namely: *By disabling repressors. The gene is expressed because an inducer binds to the repressor. The binding of the inducer to the r ...

s of

CYP2C8 Cytochrome P4502C8 (CYP2C8) is a member of the cytochrome P450 mixed-function oxidase system involved in the metabolism of xenobiotics in the body. Cytochrome P4502C8 also possesses epoxygenase activity, i.e. it metabolizes long-chain polyunsat ...

and CYP3A4, and should be avoided if possible. In a clinical study of enzalutamide for -positive

breast cancer Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipp ...

in women, enzalutamide was found to decrease serum concentrations of the

aromatase inhibitor Aromatase inhibitors (AIs) are a class of drugs used in the treatment of breast cancer in postmenopausal women and in men, and gynecomastia in men. They may also be used off-label to reduce estrogen conversion when supplementing testosterone exo ...

anastrozole Anastrozole, sold under the brand name Arimidex among others, is an antiestrogenic medication used in addition to other treatments for breast cancer. Specifically it is used for hormone receptor-positive breast cancer. It has also been used t ...

and exemestane by 90% and 50%, respectively, which could reduce their effectiveness.

Pharmacology

Pharmacodynamics

Enzalutamide acts as a selective silent

(AR), the

s like

and

(DHT). Unlike the first-generation NSAA

bicalutamide 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 remo ...

, enzalutamide does not promote translocation of AR to the

cell nucleus The cell nucleus (; : nuclei) is a membrane-bound organelle found in eukaryote, eukaryotic cell (biology), cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have #Anucleated_cells, ...

and in addition prevents binding of AR to

deoxyribonucleic acid Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of a ...

(DNA) and AR to

coactivator A coactivator is a type of transcriptional coregulator that binds to an activator (a transcription factor) to increase the rate of transcription of a gene or set of genes. The activator contains a DNA binding domain that binds either to a DNA ...

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

s. As such, it has been described as an AR signaling inhibitor in addition to antagonist. The drug is described as a "second-generation" NSAA because it has greatly increased efficacy as an antiandrogen relative to so-called "first-generation" NSAAs like

flutamide Flutamide, sold under the brand name Eulexin among others, is a nonsteroidal antiandrogen (NSAA) which is used primarily to treat prostate cancer. It is also used in the treatment of androgen-dependent conditions like acne, hirsutism, excessive ...

and bicalutamide. The drug has only 2-fold lower affinity for the AR than DHT, the endogenous ligand of the AR in the prostate gland. When LNCaP cells (a prostate cancer cell line) engineered to express elevated levels of AR (as found in patients with advanced prostate cancer) were treated with enzalutamide, the expression of androgen-dependent genes PSA and

TMPRSS2 Transmembrane protease, serine 2 is an enzyme that in humans is encoded by the ''TMPRSS2'' gene. It belongs to the TMPRSS family of proteins, whose members are transmembrane proteins which have a serine protease activity. The TMPRSS2 protein is ...

was down regulated in contrast to bicalutamide where the expression was upregulated. In VCaP cells which over-express the AR, enzalutamide induced

apoptosis Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...

whereas bicalutamide did not. Furthermore, enzalutamide behaves as an antagonist of the W741C mutant AR in contrast to bicalutamide which behaves as a pure

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

when bound to the W741C mutant. Dose-ranging studies of enzalutamide in men with prostate cancer have been performed.

Changes in hormone levels

Enzalutamide monotherapy at a dosage of 160 mg/day has been found to increase circulating levels of

by 114.3%,

(DHT) by 51.7%,

estradiol Estradiol (E2), also called oestrogen, oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of female reproductive cycles such as estrous and menstrual cycles. Estradiol is responsible ...

by 71.7%,

sex hormone-binding globulin Sex hormone-binding globulin (SHBG) or sex steroid-binding globulin (SSBG) is a glycoprotein that binds to androgens and estrogens. When produced by the Sertoli cells in the seminiferous tubules of the testis, it is called androgen-binding prot ...

(SHBG) by 100.6%,

dehydroepiandrosterone Dehydroepiandrosterone (DHEA), also known as androstenolone, is an endogenous steroid hormone precursor. It is one of the most abundant circulating steroids in humans. DHEA is produced in the adrenal glands, the gonads, and the brain. It funct ...

(DHEA) by 9.6%,

androstenedione Androstenedione, or 4-androstenedione (abbreviated as A4 or Δ4-dione), also known as androst-4-ene-3,17-dione, is an endogenous weak androgen steroid hormone and intermediate in the biosynthesis of estrone and of testosterone from dehydroe ...

by 51.1%,

luteinizing hormone Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (G ...

(LH) by 184.7%,

follicle-stimulating hormone Follicle-stimulating hormone (FSH) is a gonadotropin, a glycoprotein polypeptide hormone. FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, puberty, pubertal maturat ...

(FSH) by 47.0%, and

prolactin Prolactin (PRL), also known as lactotropin and mammotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secr ...

by 16.8%. These changes in hormone levels are similar to those with high-dose bicalutamide monotherapy. The median maximum decrease in levels of prostate-specific antigen (PSA) levels was 99.6%.

Comparison with other antiandrogens

Enzalutamide has approximately 8-fold higher

binding affinity In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from Latin ''ligare'', which means 'to bind'. In protein-ligand binding, the ligand is usuall ...

for the

androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone, in th ...

(AR) compared to

. One study found an of 21 nM for enzalutamide and 160 nM for bicalutamide at the AR in the LNCaP cell line (7.6-fold difference), while another found respective IC₅₀ values of 36 nM and 159 nM (4.4-fold difference). In accordance, clinical findings suggest that enzalutamide is a significantly more potent and effective antiandrogen in comparison to first-generation NSAAs such as bicalutamide, flutamide, and nilutamide. Also, unlike with the first-generation NSAAs, there has been no evidence of

hepatotoxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury (DILI) is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdr ...

or elevated liver enzymes in association with enzalutamide treatment in clinical trials.

Resistance mechanisms in prostate cancer

Enzalutamide is only effective for a certain period of time, after that the growth of the cancer is not inhibited by this antiandrogen. The mechanisms of resistance to Enzalutamide are being intensively studied. Currently, several mechanisms have been found: * AR mutations * AR

splice variant Alternative splicing, alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to produce different splice variants. For example, some exons of a gene may be included ...

s *

Glucocorticoid receptor The glucocorticoid receptor (GR or GCR) also known by its gene name ''NR3C1'' ( nuclear receptor subfamily 3, group C, member 1) is the steroid receptor for glucocorticoids such as cortisol. The GR is expressed in almost every cell in the bod ...

bypass * Increase in

flux Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications in physics. For transport phe ...

glycolysis Glycolysis is the metabolic pathway that converts glucose () into pyruvic acid, pyruvate and, in most organisms, occurs in the liquid part of cells (the cytosol). The Thermodynamic free energy, free energy released in this process is used to form ...

Autophagy Autophagy (or autophagocytosis; from the Greek language, Greek , , meaning "self-devouring" and , , meaning "hollow") is the natural, conserved degradation of the cell that removes unnecessary or dysfunctional components through a lysosome-depe ...

mediated resistance * Wnt signaling activation * Increase in intra-tumoral androgen biosynthesis mediated by AKR1C3 enzyme *

Interleukin 6 Interleukin 6 (IL-6) is an interleukin that acts as both a pro-inflammatory cytokine and an anti-inflammatory myokine. In humans, it is encoded by the ''IL6'' gene. In addition, osteoblasts secrete IL-6 to stimulate osteoclast formation. Smoo ...

signaling mediated resistance

Cytochrome P450 modulation

Enzalutamide is reported to be a strong

of the

and a moderate inducer of

and

, and can affect the circulating concentrations of drugs that are metabolized by these enzymes.

Pharmacokinetics

The

bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. H ...

of enzalutamide in humans is unknown, but is at least 84.6% based on the amount recovered from

urine Urine is a liquid by-product of metabolism in humans and many other animals. In placental mammals, urine flows from the Kidney (vertebrates), kidneys through the ureters to the urinary bladder and exits the urethra through the penile meatus (mal ...

and

bile Bile (from Latin ''bilis''), also known as gall, is a yellow-green/misty green fluid produced by the liver of most vertebrates that aids the digestion of lipids in the small intestine. In humans, bile is primarily composed of water, is pro ...

excretion Excretion is elimination of metabolic waste, which is an essential process in all organisms. In vertebrates, this is primarily carried out by the lungs, Kidney (vertebrates), kidneys, and skin. This is in contrast with secretion, where the substa ...

studies. Similarly, the bioavailability of enzalutamide in rats is 89.7%.

Steady-state In systems theory, a system or a process is in a steady state if the variables (called state variables) which define the behavior of the system or the process are unchanging in time. In continuous time, this means that for those properties ''p'' ...

concentrations of enzalutamide are achieved within 28 days of treatment initiation. The

plasma protein binding Plasma protein binding refers to the degree to which medications attach to blood proteins within the blood plasma. A drug's efficacy may be affected by the degree to which it binds. The less bound a drug is, the more efficiently it can traverse o ...

of enzalutamide is 97 to 98%, while that of ''N''-desmethylenzalutamide (NDME), its major

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

, is 95%. Enzalutamide is primarily bound to

albumin Albumin is a family of globular proteins, the most common of which are the serum albumins. All of the proteins of the albumin family are water- soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Alb ...

. The medication is

metabolized Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

in the

liver The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...

, mainly by the

and

. CYP2C8 is primarily responsible for the formation of NDME. Enzalutamide has a long

elimination half-life Biological half-life (elimination half-life, pharmacological half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the blood plasma. ...

of 5.8 days on average, with a range of 2.8 to 10.2 days. The elimination half-life of NDME is even longer, at about 7.8 to 8.6 days. Enzalutamide is eliminated 71.0% in

, 13.6% in

, and 0.39% in

feces Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...

Chemistry

Enzalutamide is a

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

aryl In organic chemistry, an aryl is any functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, such as phenyl and naphthyl. "Aryl" is used for the sake of abbreviation or generalization, and "Ar" is used ...

thiohydantoin

derivative In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...

and is structurally related to the earlier first-generation NSAAs such as

, nilutamide, and

as well as to newer second-generation NSAAs like apalutamide and proxalutamide.

History

Enzalutamide was discovered by Charles Sawyers and Michael Jung at the

University of California, Los Angeles The University of California, Los Angeles (UCLA) is a public university, public Land-grant university, land-grant research university in Los Angeles, California, United States. Its academic roots were established in 1881 as a normal school the ...

. They and their colleagues synthesized and evaluated nearly 200 thiohydantoin

s of RU-59063, an analogue of nilutamide, for AR antagonism in human prostate cancer cells, and identified enzalutamide and RD-162 as lead compounds. These compounds were

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

ed in 2006 and described in 2007.Sawyers, C., Jung, M., Chen, C., Ouk, S., Welsbie, D., Tran, C., ... & Yoo, D. (2006). U.S. Patent Application No. 11/433,829. https://patents.google.com/patent/US2007000475

/ref> Enzalutamide was developed and marketed by

Medivation Medivation, Inc. was an American biopharmaceutical company focused on development of novel therapies to treat serious diseases for which there are limited treatment options. Medivation was headquartered in San Francisco, California, beginning oper ...

for the treatment of prostate cancer. It was approved by the US

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) for the treatment of mCRPC in the United States in August 2012, and for the treatment of nonmetastatic castration-resistant prostate cancer in July 2018. Enzalutamide was the first new AR antagonist to be approved for the treatment of prostate cancer in over 15 years, following the introduction of the first-generation NSAA

in 1995. It was the first second-generation NSAA to be introduced. In July 2018, the FDA approved enzalutamide for the treatment of people with castration-resistant prostate cancer. The approval broadens the indication to include people with both non-metastatic castration-resistant prostate cancer and metastatic castration-resistant prostate cancer. Enzalutamide was previously approved for the treatment of people with metastatic castration-resistant prostate cancer. In December 2019, the FDA approved enzalutamide for the treatment of people with metastatic castration-sensitive prostate cancer (mCSPC). Enzalutamide was previously approved for the treatment of people with castration-resistant prostate cancer. In June 2023, the FDA approved talazoparib, in combination with enzalutamide, for the treatment of people with homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer (mCRPC). In November 2023, the FDA approved enzalutamide for the treatment of people with non-metastatic castration-sensitive prostate cancer with biochemical recurrence at high risk for metastasis (high-risk BCR). Efficacy was evaluated in EMBARK (NCT02319837), a randomized, controlled clinical trial of 1068 patients with nmCSPC with high-risk BCR. All patients had prior definitive therapy with radical prostatectomy and/or radiotherapy with curative intent, had PSA doubling time ≤ 9 months, and were not candidates for salvage radiotherapy at enrollment. Patients were randomized 1:1:1 to receive blinded enzalutamide 160 mg once daily plus leuprolide, open-label single- agent enzalutamide 160 mg once daily, or blinded placebo once daily plus leuprolide. The application was granted

priority review Priority review is a program of the United States Food and Drug Administration (FDA) to expedite the review process for drugs that are expected to have a particularly great impact on the treatment of a disease. The priority review voucher program ...

and fast track designations.

Society and culture

Legal status

In June 2024, the

Committee for Medicinal Products for Human Use The Committee for Medicinal Products for Human Use (CHMP), formerly known as the Committee for Proprietary Medicinal Products (CPMP), is the European Medicines Agency's committee responsible for elaborating the agency's opinions on all issues regar ...

of the

European Medicines Agency The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of pharmaceutical products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products ...

adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Enzalutamide Viatris, intended for the treatment of prostate cancer. The applicant for this medicinal product is Viatris Limited. Text was copied from this source which is copyright European Medicines Agency. Reproduction is authorized provided the source is acknowledged. Enzalutamide Viatris is a generic medication, generic of Xtandi.

Economics

Pfizer reported revenue of for Xtandi in 2023.

Research

Breast cancer

Research suggests that enzalutamide may be effective in the treatment of certain types of

in women. It has been tested for the treatment of triple-negative, AR-positive breast cancer in a Phases of clinical research#Phase II, phase II

Hirsutism

Enzalutamide has been suggested as a potential treatment for hirsutism and hyperandrogenism in women with polycystic ovary syndrome.

References

{{Authority control Astellas Pharma Drugs developed by Pfizer Benzamides CYP3A4 inducers Fluoroarenes GABAA receptor negative allosteric modulators Hormonal antineoplastic drugs Imidazolidines Lactams Nitriles Nonsteroidal antiandrogens Progonadotropins Prostate cancer Thioureas Trifluoromethyl compounds