Kinase experiment:

The affinity of Elagolix sodium for hGnRH-R is determined by a competitive displacement of the radioligand GnRH from membranes prepared from HEK293 cells stably transfected with the full-length human GnRH receptor[2].

Cell experiment:

RBL-1 cells stably expressing the human cloned GnRH receptor are seeded into 96 well plates at a density of 15 000 cells per well in inositol-free DMEM containing 10% dialyzed FBS, 10 mM HEPES, 2 mM L-glutamine, 1 mM sodium pyruvate, 0.1 mM nonessential amino acids, and 50 μg/mL penicillin/streptomycin and are labeled for 48 h with 0.2 μCi myo-2-[3H]inositol. The cells are washed once in PBS and pretreated with assay buffer for 15 to 60 min at 37℃. The cells are then stimulated with GnRH (6 nM) in the presence or absence of Elagolix sodium and incubated for 60 min at 37℃[2].

Elagolix sodium is a human GnRH receptor (GnRHR) antagonist with an IC50 and Ki of 0.25 and 3.7 nM, respectively.

Elagolix sodium is a human GnRH receptor (GnRHR) antagonist with an IC50 of 0.25 nM in Kinase assay. Elagolix sodium has advanced to phase 3 trials for the treatment of endometriosis and uterine fibroids. Elagolix sodium also shows NFAT inhibition with an IC50 of 5.4 nM and effectively blocks Ca2+ flux with an IC50 of 0.86 nM[1]. Kinase assay also demonstrates that Elagolix sodium is a human GnRH receptor (GnRHR) antagonist with a Ki value of 3.7 nM[2].

References:
[1]. Kim SM, et al. Discovery of an Orally Bioavailable Gonadotropin-Releasing Hormone Receptor Antagonist. J Med Chem. 2016 Oct 13;59(19):9150-9172. Epub 2016 Sep 27.
[2]. Chen C, et al. Discovery of sodium R-(+)-4-{2-[5-(2-fluoro-3-methoxyphenyl)-3-(2-fluoro-6-[trifluoromethyl]benzyl)-4-methyl-2,6-dioxo-3,6-dihydro-2H-pyrimidin-1-yl]-1-phenylethylamino}butyrate (elagolix), a potent and orally available nonpeptide antagonist of the human gonadotropin-releasing hormone receptor. J Med Chem. 2008 Dec 11;51(23):7478-85.