rd-162 rd-162 rd-162 is a second-generation nonsteroidal antiandrogen (nsaa) which was developed for the treatment of prostate cancer but was never marketed. it acts as a potent and selective silent antagonist of the androgen receptor (ar). the drug is a diarylthiohydantoin derivative. it is closely related to enzalutamide and apalutamide. both rd-162 and enzalutamide show 5- to 8-fold higher affinity for the ar than the first-generation nsaa bicalutamide, and only 2- to 3-fold lower affinity than dihydrotestosterone (dht), the major endogenous ligand of the receptor in the prostate gland. rd-162clinical dataroutes ofadministrationby mouthdrug classnonsteroidal antiandrogenidentifiers iupac name 4--8-oxo-6-sulfanylidene-5,7-diazaspirooctan-5-yl]-2-fluoro-n-methylbenzamide cas number915087-27-3 ypubchem cid11957756chemspider10132004unii5ze6thh5vfchemblchembl1082410chemical and physical dataformulac22h16f4n4o2smolar mass476.45 g·mol−13d model (jsmol)interactive image smiles cnc(=o)c1=c(c=c(c=c1)n2c(=s)n(c(=o)c23ccc3)c4=cc(=c(c=c4)c#n)c(f)(f)f)f inchi inchi=1s/c22h16f4n4o2s/c1-28-18(31)15-6-5-14(10-17(15)23)30-20(33)29(19(32)21(30)7-2-8-21)13-4-3-12(11-27)16(9-13)22(24,25)26/h3-6,9-10h,2,7-8h2,1h3,(h,28,31)key:jpqfgmyhkskkgw-uhfffaoysa-n rd-162 and enzalutamide were developed together and were derived from the nonsteroidal androgen ru-59063, which itself was derived from the first-generation nsaa nilutamide. rd-162 and enzalutamide were selected as the lead compounds from a group of over 200 compounds that were synthesized and assayed for antiandrogenic activity. enzalutamide was ultimately selected from the two for further clinical development and was eventually marketed. rd-162 is also very closely related to apalutamide, with the two compounds differing only by the replacement of a single atom (a carbon atom in one of the phenyl rings of rd-162 swapped with a nitrogen atom in apalutamide). apalutamide was approved for the treatment of prostate cancer in 2018.