pipendoxifene pipendoxifene pipendoxifene (inn) (developmental code name era-923) is a nonsteroidal selective estrogen receptor modulator (serm) that was under development by ligand pharmaceuticals and wyeth-ayerst laboratories (now wyeth) for the treatment of breast cancer but was not marketed. it is a member of the 2-phenylindole group of serms and is structurally related to zindoxifene and the marketed bazedoxifene. the drug reached phase ii clinical trials before its development was discontinued. it was synthesized at the same time as bazedoxifene and was intended as a backup drug for bazedoxifene, only to be developed further if bazedoxifene had failed in clinical trials. no further development was reported after 2002 and it was formally announced that development had been terminated in november 2005. pipendoxifeneclinical dataother namesera-923identifiers iupac name 2-(4-hydroxyphenyl)-3-methyl-1-methyl]indol-5-ol cas number198480-55-6pubchem cid6433099chemspider4938287uniitpc5q8496gchemblchembl44426chemical and physical dataformulac29h32n2o3molar mass456.586 g·mol−13d model (jsmol)interactive image smiles cc1=c(n(c2=c1c=c(c=c2)o)cc3=cc=c(c=c3)occn4ccccc4)c5=cc=c(c=c5)o inchi inchi=1s/c29h32n2o3/c1-21-27-19-25(33)11-14-28(27)31(29(21)23-7-9-24(32)10-8-23)20-22-5-12-26(13-6-22)34-18-17-30-15-3-2-4-16-30/h5-14,19,32-33h,2-4,15-18,20h2,1h3key:jicogkjoqxtaip-uhfffaoysa-n unlike the serm raloxifene, pipendoxifene is devoid of uterotrophic activity in immature/ovariectomized rodents.