Sufugolix (INNTooltip International Nonproprietary Name, BANTooltip British Approved Name) (developmental code name TAK-013) is a non-peptide, orally-active, selective antagonist of the gonadotropin-releasing hormone receptor (GnRHR) (IC50Tooltip Half-maximal inhibitory concentration = 0.1 and 0.06 nM for affinity and in vitro inhibition, respectively).

[1] It was under development by Takeda for the treatment of endometriosis and uterine leiomyoma and reached phase II clinical trials for both of these indications, but was subsequently discontinued.

[2][3] It seems to have been supplanted by relugolix (TAK-385), which is also under development by Takeda for the treatment of these conditions and has a more favorable drug profile (including reduced cytochrome P450 inhibition and improved in vivo GnRHR antagonistic activity) in comparison.

[4] Oral administration of sufugolix at a dose of 30 mg/kg to castrated male cynomolgus monkeys resulted in nearly complete suppression of luteinizing hormone levels.

[1] The suppressive effects of sufugolix on gonadotropin and sex hormone levels are rapidly reversible with discontinuation.