opigolix opigolix opigolix (inn, usan; developmental code name asp-1707) is a small-molecule, non-peptide, orally active gonadotropin-releasing hormone antagonist (gnrh antagonist) which was under development by astellas pharma for the treatment of endometriosis and rheumatoid arthritis. it was also under investigation for the treatment of prostate cancer. it reached phase ii clinical trials for both endometriosis and rheumatoid arthritis prior to the discontinuation of its development in april 2018. opigolixclinical dataother namesasp-1707routes ofadministrationby mouthdrug classgnrh modulator; gnrh antagonist; antigonadotropinidentifiers iupac name (2r)-n'--2-fluorophenyl]sulfonyl-2-hydroxypropanimidamide cas number912587-25-8 ypubchem cid11977994uniivq6ck0citakeggd11351chemical and physical dataformulac25h19f3n4o5smolar mass544.51 g·mol−13d model (jsmol)interactive image smiles c(o)/c(n)=n/s(=o)(=o)c1cc(c(=o)c(c(=o)c2cc(f)ccc2f)=c2nc3ccccc3n2)ccc1f inchi inchi=1s/c25h19f3n4o5s/c1-12(33)24(29)32-38(36,37)20-10-13(6-8-17(20)28)22(34)21(23(35)15-11-14(26)7-9-16(15)27)25-30-18-4-2-3-5-19(18)31-25/h2-12,30-31,33h,1h3,(h2,29,32)/t12-/m1/s1key:cwnlbpbifaluqd-gfccvegcsa-n