leflutrozole leflutrozole leflutrozole (developmental code names bgs-649, cgp-47645) is an aromatase inhibitor which is under development by mereo biopharma and novartis for the treatment of hypogonadism in men. it was also under investigation for the treatment of endometriosis, but development for this indication was discontinued. as of december 2017, leflutrozole is in phase ii clinical trials for hypogonadism. leflutrozoleclinical dataother namesbgs-649; cgp-47645routes ofadministrationby mouthidentifiers iupac name 4-benzonitrile cas number143030-47-1pubchem cid126735chemspider112569uniircx0ie6ejzchemblchembl225550comptox dashboard (epa)dtxsid80162296 chemical and physical dataformulac17h10fn5molar mass303.300 g·mol−13d model (jsmol)interactive image smiles c1=cc(=cc=c1c#n)c(c2=cc=c(c=c2)c#n)(n3c=nc=n3)f inchi inchi=1s/c17h10fn5/c18-17(23-12-21-11-22-23,15-5-1-13(9-19)2-6-15)16-7-3-14(10-20)4-8-16/h1-8,11-12hkey:pzdlrbuqywmnbr-uhfffaoysa-n