Inocoterone acetate

Inocoterone acetate
Clinical data
Other names	RU-38882; RU-882; 2,5-Seco-A-dinorestr-9-en-17β-ol-5-one 17β-acetate
Drug class	Nonsteroidal antiandrogen
Identifiers
	IUPAC name [(3S,3aS,9aS,9bS)-6-Ethyl-3a-methyl-7-oxo-2,3,4,5,8,9,9a,9b-octahydro-1H-cyclopenta[a]naphthalen-3-yl] acetate;
CAS Number	83646-86-0;
PubChem CID	6917958;
ChemSpider	5293176;
UNII	ONU02D116S;
KEGG	D04538;
ChEMBL	ChEMBL2107564;
CompTox Dashboard (EPA)	DTXSID401003615 ;
Chemical and physical data
Formula	C18H26O3
Molar mass	290.403 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES CCC1=C2CC[C@]3([C@H]([C@@H]2CCC1=O)CC[C@@H]3OC(=O)C)C;
	InChI InChI=1S/C18H26O3/c1-4-12-13-9-10-18(3)15(14(13)5-7-16(12)20)6-8-17(18)21-11(2)19/h14-15,17H,4-10H2,1-3H3/t14-,15+,17+,18+/m1/s1; Key:JDLUQDYTLSPFGS-FZCLSBEQSA-N;

Inocoterone acetate (USANTooltip United States Adopted Name; developmental codes RU-38882 and RU-882) is a steroid-like nonsteroidal antiandrogen (NSAA) that was developed for topical administration to treat acne but was never marketed. It is the acetate ester of inocoterone, which is less potent in comparison. Inocoterone acetate is actually not a silent antagonist of the androgen receptor but rather a weak partial agonist, similarly to steroidal antiandrogens like cyproterone acetate.

Inocoterone acetate was investigated for the treatment of acne but showed only modest (albeit statistically significant) efficacy in clinical trials. A reduction of 26% of lesions was observed in males treated with the drug after 16 weeks (~3.7 months). However, this is notably far less than that achieved with other agents such as benzoyl peroxide or antibiotics, which produce 50–75% reductions within 2 months. Similar poor results with the topical route have disappointingly been found for other antiandrogens, such as cyproterone acetate and spironolactone. Similarly to rosterolone, inocoterone acetate has no systemic antiandrogenic activity when applied systemically.