Fenclozic acid

Trade namesMyalex

CAS Number

• 17969-20-9 ^Y

PubChem CID

• 28858

ChemSpider

• 26843 ^N

Fenclozic acid

Clinical data
Trade names	Myalex
Identifiers
IUPAC name [2-(4-Chlorophenyl)-1,3-thiazol-4-yl]acetic acid
CAS Number	17969-20-9 Y
PubChem CID	28858
ChemSpider	26843 N
UNII	58SRQ4DV53
CompTox Dashboard (EPA)	DTXSID4046157
Chemical and physical data
Formula	C11H8ClNO2S
Molar mass	253.70 g·mol−1
3D model (JSmol)	Interactive image
SMILES c1cc(ccc1c2nc(cs2)CC(=O)O)Cl
InChI InChI=1S/C11H8ClNO2S/c12-8-3-1-7(2-4-8)11-13-9(6-16-11)5-10(14)15/h1-4,6H,5H2,(H,14,15) N Key:APBSKHYXXKHJFK-UHFFFAOYSA-N N
NY (what is this?)  (verify)

Fenclozic acid (proposed brand name Myalex) is a nonsteroidal anti-inflammatory drug (NSAID) with analgesic, antipyretic, and anti-inflammatory properties developed in 1960s by ICI Pharmaceuticals.^[1][2] It failed to pass Phase III clinical trial and was withdrawn from clinical development in 1971 due to severe dose-related hepatotoxicity and jaundice in human, despite showing excellent preclinical safety profile and promising clinical efficacy in animal testings.^[3][4] It is considered a classic example of human-specific drug induced liver injury linked to unique metabolic activation in humans.^[4][5]