Anderson RA, Cormier J, Thieroff-Ekerdt R, et al. - Given that SJX-653 is a novel neurokinin 3 receptor (NK3R) antagonist, researchers conducted this randomized, placebo-controlled, double-blind, single ascending dose study to describe the safety, tolerability, pharmacokinetics, and pharmacodynamic activity of SJX-653 in healthy men. The sample consisted of 6 healthy men 18-45 years (4:2 randomization to SJX-653/placebo per cohort). Inverventions included single oral doses of 0.5 to 90 mg SJX-653. at All dose levels, SJX-653 was well tolerated. C_max and AUC_0-24 increased in a dose proportional manner. Data reported that the plasma IC₅₀ for LH reduction was 33 ng/mL. Such data show clinical proof-of-mechanism for SJX-653 as a potent centrally-acting NK3R antagonist.