[CAS NO. 832720-36-2]  Elagolix Sodium

Elagolix displays high affinity in a competition binding assay for hGnRH-R (Ki = 0.90 nM) and low CYP3A4 inhibition (IC50 = 56 μM). It is a slowly disassociating antagonist exhibiting very high affinity (KD = 54 pM) and insurmountable antagonism. Elagolix is highly selective at hGnRH-R, its wider receptor selectivity is tested at a concentration of 10 μM in a panel of radioligand binding assays for 100 off-target receptors, ion channels, enzymes, and transporters, and significant activity is not observed (inhibition <50%). It does not stimulate histamine release from cultured rat peritoneal mast cells. Elagolix lacks the necessary high binding affinity to the rat GnRH receptor (Ki = 4400 nM) and it possesses high affinity at the monkey GnRH receptor (Ki = 3.3 nM).