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2D Structure
Also known as: 90357-06-5, Casodex, Bicalutamide (cdx), Calutide, Ici 176334, Ici-176334
Molecular Formula
C18H14F4N2O4S
Molecular Weight
430.4  g/mol
InChI Key
LKJPYSCBVHEWIU-UHFFFAOYSA-N
FDA UNII
A0Z3NAU9DP

Bicalutamide is a synthetic, nonsteroidal antiandrogen. Bicalutamide competitively binds to cytosolic androgen receptors in target tissues, thereby inhibiting the receptor binding of androgens. This agent does not bind to most mutated forms of androgen receptors. (NCI04)
Bicalutamide is an Androgen Receptor Inhibitor. The mechanism of action of bicalutamide is as an Androgen Receptor Antagonist.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
N-[4-cyano-3-(trifluoromethyl)phenyl]-3-(4-fluorophenyl)sulfonyl-2-hydroxy-2-methylpropanamide
2.1.2 InChI
InChI=1S/C18H14F4N2O4S/c1-17(26,10-29(27,28)14-6-3-12(19)4-7-14)16(25)24-13-5-2-11(9-23)15(8-13)18(20,21)22/h2-8,26H,10H2,1H3,(H,24,25)
2.1.3 InChI Key
LKJPYSCBVHEWIU-UHFFFAOYSA-N
2.1.4 Canonical SMILES
CC(CS(=O)(=O)C1=CC=C(C=C1)F)(C(=O)NC2=CC(=C(C=C2)C#N)C(F)(F)F)O
2.2 Other Identifiers
2.2.1 UNII
A0Z3NAU9DP
2.3 Synonyms
2.3.1 MeSH Synonyms

1. 4'-cyano-3-(4-fluorophenylsulfonyl)-2-hydroxy-2-methyl-3'-(trifluoromethyl)propionanilide

2. Casodex

3. Cosudex

4. Ici 176334

5. Ici-176334

2.3.2 Depositor-Supplied Synonyms

1. 90357-06-5

2. Casodex

3. Bicalutamide (cdx)

4. Calutide

5. Ici 176334

6. Ici-176334

7. N-(4-cyano-3-(trifluoromethyl)phenyl)-3-((4-fluorophenyl)sulfonyl)-2-hydroxy-2-methylpropanamide

8. N-[4-cyano-3-(trifluoromethyl)phenyl]-3-(4-fluorophenyl)sulfonyl-2-hydroxy-2-methylpropanamide

9. Ici 176,334

10. Bicalutamide (casodex)

11. Cosudex

12. A0z3nau9dp

13. Chembl409

14. Nsc-759816

15. N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2-hydroxy-2-methylpropanamide

16. Ici176,334-1

17. Propanamide, N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2-hydroxy-2-methyl-

18. Raffolutil

19. Kalumid

20. Smr000466329

21. Casodex (tn)

22. Sr-01000759410

23. Unii-a0z3nau9dp

24. Brn 5364666

25. Bicalutamine

26. Bicalutamide (jan/usp/inn)

27. Propanamide,

28. Ccris 8728

29. Hsdb 7655

30. Bicalutamide [usan:usp:inn:ban]

31. Mfcd00869971

32. (+-)-4'-cyano-alpha,alpha,alpha-trifluoro-3-((p-fluorophenyl)sulfonyl)-2-methyl-m-lactotoluidide

33. Ks-1161

34. Bicalutamide - Casodex

35. Cpd000466329

36. Bicalutamide [mi]

37. Bicalutamide [inn]

38. Bicalutamide [jan]

39. Bicalutamide [hsdb]

40. Bicalutamide [usan]

41. Schembl3611

42. Bicalutamide [vandf]

43. Bicalutamide [mart.]

44. (r)-(-)-bicalutamide-d4

45. Mls000759437

46. Mls001424047

47. Propanamide, N-(4-cyano-3-(trifluoromethyl)phenyl)-3-((4-fluorophenyl)sulfonyl)-2-hydroxy-2-methyl-, (+-)-

48. S-(+)-bicalutamide-[d4]

49. Bicalutamide [usp-rs]

50. Bicalutamide [who-dd]

51. Gtpl2863

52. Dtxsid2022678

53. Bdbm18525

54. Chebi:91617

55. Ex-a962

56. Chebi:144093

57. Bcpp000337

58. Bicalutamide [orange Book]

59. Hms2051b13

60. Hms2089n12

61. Hms2232h03

62. Hms3263m13

63. Hms3372k05

64. Hms3393b13

65. Hms3654k18

66. Hms3714p13

67. Pharmakon1600-01504827

68. Bicalutamide [ep Monograph]

69. Bicalutamide [usp Impurity]

70. Act06291

71. Amy33430

72. Bcp02110

73. Bicalutamide [usp Monograph]

74. Tox21_501026

75. Nsc722665

76. Nsc759816

77. S1190

78. Akos015895073

79. Ac-4232

80. Bcp9000408

81. Ccg-100951

82. Ccg-220876

83. Ccg-222330

84. Cs-1296

85. Db01128

86. Lp01026

87. Nc00201

88. Nsc 759816

89. Nsc-722665

90. Sb17301

91. Sdccgsbi-0633779.p001

92. N-(4-cyano-3-(trifluoromethyl)phenyl)

93. Ncgc00167977-01

94. Ncgc00167977-02

95. Ncgc00167977-03

96. Ncgc00167977-09

97. Ncgc00167977-20

98. Ncgc00261711-01

99. Hy-14249

100. Db-041165

101. B3206

102. Ft-0618286

103. Ft-0631069

104. Ft-0663100

105. Sw197581-4

106. Bicalutamide (cdx), >=98% (hplc), Powder

107. C08160

108. D00961

109. Ab00639963-06

110. Ab00639963-08

111. Ab00639963-09

112. Ab00639963_10

113. 357b065

114. A803039

115. A843528

116. Q1988832

117. Sr-01000759410-4

118. Sr-01000759410-5

119. Brd-a29485665-001-03-7

120. Bicalutamide, British Pharmacopoeia (bp) Reference Standard

121. Bicalutamide, European Pharmacopoeia (ep) Reference Standard

122. Bicalutamide, United States Pharmacopeia (usp) Reference Standard

123. 4'-cyano-3-[(4- Fluorophenyl)sulfonyl]-2-hydroxy-2-methyl-3'-trifluoromethylpropionanilide

124. 4'-cyano-3-[(4-fluorophenyl)sulfonyl]-2-hydroxy-2-methyl-3'-trifluoromethylpropionanilide

125. Bicalutamide For System Suitability, European Pharmacopoeia (ep) Reference Standard

126. Bicalutamide, Pharmaceutical Secondary Standard; Certified Reference Material

127. (+/-)-4'-cyano-.alpha.,.alpha.,.alpha.-trifluoro-3-((p-fluorophenyl)sulfonyl)-2-methyl-m-lactotoluidide

128. N-(4-cyano-3-(trifluoromethyl)phenyl)-3-((4-fluorophenyl)sulfonyl)-2-hydroxy-2-methyl-n-phenylpropanamide

129. N-(4-cyano-3-(trifluoromethyl)phenyl)-3-(4-fluorophenylsulfonyl)-2-hydroxy-2-methylpropanamide

130. N-[4-cyano-3-(trifluoromethyl)phenyl]-3-(4-fluorophenyl)sulfonyl-2-methyl-2-oxidanyl-propanamide

131. N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorobenzene)sulfonyl]-2-hydroxy-2-methylpropanamide

132. N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2-hydroxy-2-methylpropionamide

133. N-[4-cyano-3-trifluoromethyl-phenyl]-3-[4-fluorophenyl-sulfonyl]-2-hydroxy-2-methyl-propionamide

134. Propanamide, N-(4-cyano-3-(trifluoromethyl)phenyl)-3-((4-fluorophenyl)sulfonyl)-2-hydroxy-2-methyl-, (+/-)-

2.4 Create Date
2005-03-25
3 Chemical and Physical Properties
Molecular Weight 430.4 g/mol
Molecular Formula C18H14F4N2O4S
XLogP32.3
Hydrogen Bond Donor Count2
Hydrogen Bond Acceptor Count9
Rotatable Bond Count5
Exact Mass430.06104075 g/mol
Monoisotopic Mass430.06104075 g/mol
Topological Polar Surface Area116 Ų
Heavy Atom Count29
Formal Charge0
Complexity750
Isotope Atom Count0
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count1
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently Bonded Unit Count1
4 Drug and Medication Information
4.1 Drug Information
1 of 4  
Drug NameBicalutamide
PubMed HealthBicalutamide (By mouth)
Drug ClassesAntiandrogen
Drug LabelBicalutamide tablets contain 50 mg of bicalutamide, a non-steroidal androgen receptor inhibitor with no other known endocrine activity. The chemical name is propanamide, N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2-hydroxy-2-m...
Active IngredientBicalutamide
Dosage FormTablet
RouteOral
Strength50mg
Market StatusPrescription
CompanyActavis Elizabeth; Fresenius Kabi Oncol; Teva; Accord Hlthcare; Zydus Pharms Usa; Sandoz; Mylan; Sun Pharma Global

2 of 4  
Drug NameCasodex
PubMed HealthBicalutamide (By mouth)
Drug ClassesAntiandrogen
Drug LabelCASODEX (bicalutamide) Tablets contain 50 mg of bicalutamide, a non-steroidal androgen receptor inhibitor with no other known endocrine activity. The chemical name is propanamide, N [4 cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2...
Active IngredientBicalutamide
Dosage FormTablet
Routeoral; Oral
Strength50mg
Market StatusPrescription
CompanyAstrazeneca

3 of 4  
Drug NameBicalutamide
PubMed HealthBicalutamide (By mouth)
Drug ClassesAntiandrogen
Drug LabelBicalutamide tablets contain 50 mg of bicalutamide, a non-steroidal androgen receptor inhibitor with no other known endocrine activity. The chemical name is propanamide, N-[4-cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2-hydroxy-2-m...
Active IngredientBicalutamide
Dosage FormTablet
RouteOral
Strength50mg
Market StatusPrescription
CompanyActavis Elizabeth; Fresenius Kabi Oncol; Teva; Accord Hlthcare; Zydus Pharms Usa; Sandoz; Mylan; Sun Pharma Global

4 of 4  
Drug NameCasodex
PubMed HealthBicalutamide (By mouth)
Drug ClassesAntiandrogen
Drug LabelCASODEX (bicalutamide) Tablets contain 50 mg of bicalutamide, a non-steroidal androgen receptor inhibitor with no other known endocrine activity. The chemical name is propanamide, N [4 cyano-3-(trifluoromethyl)phenyl]-3-[(4-fluorophenyl)sulfonyl]-2...
Active IngredientBicalutamide
Dosage FormTablet
Routeoral; Oral
Strength50mg
Market StatusPrescription
CompanyAstrazeneca

4.2 Therapeutic Uses

Androgen Antagonists; Antineoplastic Agents

National Library of Medicine's Medical Subject Headings online file (MeSH, 1999)


/Bicalutamide/ 50 mg daily is indicated for use in combination therapy with a luteinizing hormone-releasing hormone (LHRH) analogue for the treatment of Stage D2 metastatic carcinoma of the prostate. /Included in US product label/

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


/Bicalutamide/ 150 mg daily is not approved for use alone or with other treatments. /Included in US product label/

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


4.3 Drug Warning

/Bicalutamide/ is contraindicated in any patient who has shown a hypersensitivity reaction to the drug or any of the tablet's components.

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


/Bicalutamide/ has no indication for women, and should not be used in this population, particularly for non-serious or non-life threatening conditions.

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


FDA Pregnancy Risk Category: X /CONTRAINDICATED IN PREGNANCY. Studies in animals and or humans, or investigational or post-marketing reports, have demonstrated positive evidence of fetal abnormalities or risk which clearly outweighs any possible benefit to the patient./

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


It is not known whether /bicalutamide/ drug is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when /bicalutamide/ is administered to a nursing woman.

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


For more Drug Warnings (Complete) data for BICALUTAMIDE (10 total), please visit the HSDB record page.


4.4 Drug Indication

For treatment (together with surgery or LHRH analogue) of advanced prostatic cancer.


FDA Label


5 Pharmacology and Biochemistry
5.1 Pharmacology

Bicalutamide is an antineoplastic hormonal agent primarily used in the treatment of prostate cancer. Bicalutamide is a pure, nonsteroidal anti-androgen with affinity for androgen receptors (but not for progestogen, estrogen, or glucocorticoid receptors). Consequently, Bicalutamide blocks the action of androgens of adrenal and testicular origin which stimulate the growth of normal and malignant prostatic tissue. Prostate cancer is mostly androgen-dependent and can be treated with surgical or chemical castration. To date, antiandrogen monotherapy has not consistently been shown to be equivalent to castration.


5.2 MeSH Pharmacological Classification

Androgen Antagonists

Compounds which inhibit or antagonize the biosynthesis or actions of androgens. (See all compounds classified as Androgen Antagonists.)


Antineoplastic Agents

Substances that inhibit or prevent the proliferation of NEOPLASMS. (See all compounds classified as Antineoplastic Agents.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
BICALUTAMIDE
5.3.2 FDA UNII
A0Z3NAU9DP
5.3.3 Pharmacological Classes
Androgen Receptor Inhibitor [EPC]; Androgen Receptor Antagonists [MoA]
5.4 ATC Code

L02BB03

S76 | LUXPHARMA | Pharmaceuticals Marketed in Luxembourg | Pharmaceuticals marketed in Luxembourg, as published by d'Gesondheetskeess (CNS, la caisse nationale de sante, www.cns.lu), mapped by name to structures using CompTox by R. Singh et al. (in prep.). List downloaded from https://cns.public.lu/en/legislations/textes-coordonnes/liste-med-comm.html. Dataset DOI:10.5281/zenodo.4587355


L - Antineoplastic and immunomodulating agents

L02 - Endocrine therapy

L02B - Hormone antagonists and related agents

L02BB - Anti-androgens

L02BB03 - Bicalutamide


5.5 Absorption, Distribution and Excretion

Absorption

Bicalutamide is well-absorbed following oral administration, although the absolute bioavailability is unknown.


Clearance

Apparent oral cl=0.32 L/h [Normal Males]


Bicalutamide is well-absorbed following oral administration, although the absolute bioavailability is unknown. Co-administration of bicalutamide with food has no clinically significant effect on rate or extent of absorption.

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


Bicalutamide is highly protein-bound (96%).

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


... Bicalutamide metabolites are excreted almost equally in urine and feces with little or no unchanged drug excreted in urine; conversely, unchanged drug predominates in plasma. Bicalutamide in feces is thought to arise from hydrolysis of bicalutamide glucuronide and from unabsorbed drug. ...

PMID:15509184 Cockshott ID; Clin Pharmacokinet 43 (13): 855-78 (2004)


... Healthy male volunteers (n = 15) were administered single oral doses of bicalutamide (50 mg) after food and after fasting as part of a three-treatment, three-period, randomized cross-over study, with a 9 week washout. After fasting, plasma concentrations of (R)-bicalutamide were much higher than those of (S)-bicalutamide; the mean (R)-enantiomer Cmax (734 ng mL-1) was about nine times higher than the (S)-enantiomer value (84 ng mL-1). The corresponding tmax values were 19 and 3 hr for (R)- and (S)-bicalutamide, respectively. Elimination of (R)-bicalutamide from plasma was monoexponential and slow (t1/2 = 5.8 d). Elimination of (S)-bicalutamide was biphasic in some volunteers but monophasic in others (terminal t1/2 =1.2 d; n = 11). There was no significant effect of food on AUC, tmax, or t1/2 data for either enantiomer. The observed slightly higher values of Cmax for (R)-bicalutamide (14%) and (S)-bicalutamide (19%), when dosing with food, achieved statistical significance. ...

PMID:9312310 Cockshott ID et al; Biopharm Drug Dispos 18 (6): 499-507 (1997)


For more Absorption, Distribution and Excretion (Complete) data for BICALUTAMIDE (9 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Bicalutamide undergoes stereo specific metabolism. The S (inactive) isomer is metabolized primarily by glucuronidation. The R (active) isomer also undergoes glucuronidation but is predominantly oxidized to an inactive metabolite followed by glucuronidation.


Bicalutamide undergoes stereospecific metabolism. The S (inactive) isomer is metabolized primarily by glucuronidation. The R (active) isomer also undergoes glucuronidation but is predominantly oxidized to an inactive metabolite followed by glucuronidation. Both the parent and metabolite glucuronides are eliminated in the urine and feces. The S-enantiomer is rapidly cleared relative to the R-enantiomer, with the R-enantiomer accounting for about 99% of total steady-state plasma levels.

US Natl Inst Health; DailyMed. Current Medication Information for Casodex (Bicalutamide) (August 2007). Available from, as of November 12, 2008: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?id=4740


5.7 Biological Half-Life

5.9 days


... Elimination of (S)-bicalutamide was biphasic in some volunteers but monophasic in others (terminal t1/2 =1.2 d; n = 11). ...

PMID:9312310 Cockshott ID et al; Biopharm Drug Dispos 18 (6): 499-507 (1997)


/The/ apparent plasma elimination half-life observed following repeated administration was 8.4 +/- 1.1 days.

PMID:8712091 Kotake T et al; Hinyokika Kiyo 42 (2): 143-53 (1996)


5.8 Mechanism of Action

Bicalutamide competes with androgen for the binding of androgen receptors, consequently blocking the action of androgens of adrenal and testicular origin which stimulate the growth of normal and malignant prostatic tissue.


Bicalutamide is a nonsteroidal antiandrogen that is structurally and pharmacologically related to flutamide and nilutamide. Bicalutamide inhibits the action of androgens by competitively blocking nuclear androgen receptors in target tissues such as the prostate, seminal vesicles, and adrenal cortex; blockade of androgen receptors in the hormone-sensitive tumor cells may result in growth arrest or transient tumor regression through inhibition of androgen-dependent DNA and protein synthesis. Bicalutamide is a selective antiandrogen with no androgenic or progestational activity in various animal models. The relative binding affinity of bicalutamide at the androgen receptor is more than that of nilutamide and approximately 4 times that of hydroxyflutamide, the active metabolite of flutamide.

McEvoy, G.K. (ed.). American Hospital Formulary Service. AHFS Drug Information. American Society of Health-System Pharmacists, Bethesda, MD. 2007., p. 944


Common pharmacologic therapies for prostate cancer (ie, gonadotropin-releasing hormone [GnRH] analogs, nonsteroidal antiandrogens) when used as monotherapy initially result in increased serum testosterone concentrations, which may limit the effects of the drugs. Androgen receptors in the hypothalamus are blocked by bicalutamide, which disrupts the inhibitory feedback of testosterone on luteinizing hormone (LH) release, resulting in a temporary increase in secretion of LH; the increase in LH stimulates an increase in the production of testosterone. As GnRH analogs have potent GnRH agonist properties, testicular steroidogenesis continues during the first few weeks after initiating therapy. However, the combination of orchiectomy or GnRH analog therapy to suppress testicular androgen production and an antiandrogen to block response of remaining adrenal androgens provides maximal androgen blockade. Concomitant administration of antiandrogens such as bicalutamide in patients initiating therapy with a GnRH analog can inhibit initial androgenic stimulation and potential exacerbation of symptoms (e.g., bone pain, urinary obstruction, liver pain, impending spinal cord compression) that may occur during the first month of GnRH analog therapy.

McEvoy, G.K. (ed.). American Hospital Formulary Service. AHFS Drug Information. American Society of Health-System Pharmacists, Bethesda, MD. 2007., p. 944


Bicalutamide was developed from a series of nonsteroidal compounds related to flutamide that showed a range of pharmacologic activity from full androgen agonist to pure antiandrogen, including progestational and antiprogestational properties. Bicalutamide is a pure antiandrogen that binds to rat, dog, and human prostate; the affinity compared with the natural ligand 5 alpha-dihydrotestosterone is low, but bicalutamide has an affinity for the rat androgen receptor approximately four times higher than hydroxyflutamide, the active metabolite of flutamide. Bicalutamide also binds to androgen receptors found in the LNCaP human prostate tumor and the Shionogi S115 mouse mammary tumor cell line, as well as androgen receptors transfected into CV-1 and HeLa cells. In all cases, bicalutamide behaves as a pure antiandrogen and inhibits gene expression and cell growth stimulated by androgen. Studies with the LNCaP cell line are particularly interesting, as these cells contain a mutated androgen receptor (codon 868, Thr-->Ala), which behaves idiosyncratically with other antiandrogens (cyproterone acetate and flutamide): both these antiandrogens act as agonists in this cell line and stimulate proliferation. Studies in vivo show that bicalutamide is a potent antiandrogen in the rat. In immature, castrated male rats treated daily with testosterone propionate, bicalutamide produces a profound inhibition of accessory sex organ (ventral prostate and seminal vesicles) growth at oral doses as low as 0.25 mg/kg; it is more active in this test than flutamide or cyproterone acetate. In mature male rats, daily oral doses of bicalutamide produce a dose-related reduction in weights of the ventral prostate glands and seminal vesicles: in this test, bicalutamide is around five times as potent as flutamide. In contrast to flutamide, which produces dose-related, marked increases in serum luteinizing hormone (LH) and testosterone as a consequence of the central inhibition of the negative feedback effects of androgens on the hypothalamic-pituitary-tests axis, bicalutamide has little effect on serum LH and testosterone; i.e., it is peripherally selective. The peripheral selectivity of bicalutamide in the rat is not due to differences between the prostate versus hypothalamic or pituitary receptors, as bicalutamide reverses the suppressive effect of testosterone on luteinizing hormone-releasing hormone (LHRH) secretion from hypothalamic slices in vitro and is as effective as flutamide at sensitizing the pituitary gland to secrete LH in response to administered LHRH. The peripheral selectivity of bicalutamide has now been shown to be due to poor penetration across the blood-brain barrier: tissue distribution studies with [3H]bicalutamide show that although it is concentrated in the organs of metabolism and secretion as well as in the prostate, the pituitary glands, and the seminal vesicles, levels in the hypothalamus and the central nervous system (CNS) are much lower than in blood. Indeed, it is probable that levels found in the CNS reflect levels of blood contamination. In dogs, bicalutamide has exquisite potency and causes dose-related atrophy of the prostate gland and epididymides; with an oral ED50 of 0.1 mg/kg, it is around 50 times as potent as flutamide in this species and also more potent than the steroidal antiandrogen WIN49596 and the 5 alpha-reductase inhibitor MK-906. Even at substantial multiples of the active dose (up to 100 mg/kg orally), bicalutamide failed to increase serum testosterone, so it is also peripherally selective in the dog.

PMID:8560673 Furr B, Tucker H; Urology 47(1A Suppl):13-25; discussion 29-32 (1996)


Although widely accepted as an androgen receptor antagonist, the mechanism by which it induces apoptosis remains unclear. Defining exact pathways by which bicalutamide induces its apoptotic effects would help to advance its clinical applications. /Investigators/ aimed to examine the apoptotic effects of bicalutamide at 24 hr and comment on the role of the caspases and calpains in mediating bicalutamide-induced apoptosis in androgen-dependent and androgen-independent cells. PWR-1E, PC-3 and DU-145 cells were treated with bicalutamide and assessed for apoptosis by flow cytometry at 24 hr. DU-145 cells were used to compare differences between two different metastatic receptor-negative cells and to verify apoptotic induction at 48 hr. To delineate a specific pathway of action for bicalutamide, PC-3 and PWR-1E cells were pretreated with specific inhibitors of caspase-dependent (zVAD-FMK) and caspase-independent pathways (calpain 2 inhibitor). Bicalutamide induced apoptosis in androgen-dependent PWR-1E cells via a caspase-dependent and calpain-independent mechanism. In androgen-independent PC-3 cells, bicalutamide also induced apoptosis by mechanisms that were partially inhibited by pan-caspase inhibition but were partially calpain dependent. Understanding into how bicalutamide exerts its effects in androgen-independent cells will yield further insights into the treatment of hormone-refractory disease.

PMID:18475288 Floyd MS Jr et al; Prostate Cancer Prostatic Dis 12 (1): 25-33 (2008)