Chemistry:Formestane

Short description: Chemical compound

Formestane

Clinical data
Trade names	Lentaron, others
Other names	4-Hydroxyandrost-4-ene-3,17-dione
AHFS/Drugs.com	International Drug Names
Routes of administration	Intramuscular injection
Drug class	Aromatase inhibitor; Antiestrogen
ATC code	L02BG02 (WHO)
Identifiers
IUPAC name (8R,9S,10R,13S,14S)-4-hydroxy-10,13-dimethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthrene-3,17-dione
CAS Number	566-48-3 Y
PubChem CID	11273
ChemSpider	10799 Y
UNII	PUB9T8T355
KEGG	D07260 Y
ChEBI	CHEBI:75172 N
ChEMBL	ChEMBL132530 Y
Chemical and physical data
Formula	C19H26O3
Molar mass	302.414 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C4C(/O)=C3/CC[C@@H]2[C@H](CC[C@@]1(C(=O)CC[C@H]12)C)[C@@]3(C)CC4
InChI InChI=1S/C19H26O3/c1-18-10-8-15(20)17(22)14(18)4-3-11-12-5-6-16(21)19(12,2)9-7-13(11)18/h11-13,22H,3-10H2,1-2H3/t11-,12-,13-,18+,19-/m0/s1 Y Key:OSVMTWJCGUFAOD-KZQROQTASA-N Y
NY (what is this?)  (verify)

Formestane, formerly sold under the brand name Lentaron among others, is a steroidal, selective aromatase inhibitor which is used in the treatment of estrogen receptor-positive breast cancer in postmenopausal women. The drug is not active orally, and was available only as an intramuscular depot injection. Formestane was not approved by the United States FDA and the injectable form that was used in Europe in the past has been withdrawn from the market. Formestane is an analogue of androstenedione.

Formestane is often used to suppress the production of estrogens from anabolic steroids or prohormones. It also acts as a prohormone to 4-hydroxytestosterone, an active steroid which displays weak androgenic activity in addition to acting as a weak aromatase inhibitor.