In this article, we will discuss Relugolix (Mechanism of Action). So, let’s get started.
Mechanism of Action
Relugolix is a nonpeptide GnRH receptor antagonist that competitively binds to pituitary GnRH receptors, thereby, reducing the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and consequently testosterone.
Pituitary and Gonadal Hormones
Relugolix reduced LH, FSH, and testosterone concentrations after oral administration of
the recommended loading dose of 360 mg and a 120 mg dose once daily. Out of 622 patients, 56% had testosterone concentrations at castrate levels (< 50 ng/dL) by the first sampling timepoint at Day 4, and 97% maintained castrate levels of testosterone through 48 weeks. In a substudy of 137 patients who did not receive subsequent androgen deprivation therapy for at least 90 days after discontinuation of relugolix, the cumulative incidence rate of achieving testosterone concentrations above the lower limit of the normal range (> 280 ng/dL) or baseline at 90 days was 55%.
In a randomized, double-blind, placebo- and positive-controlled (open-label moxifloxacin), parallel-group thorough QT/QTc study, no increase in mean QTc interval > 10 ms was identified after administration of single 60 or 360 mg doses of relugolix (0.2 or 1 times the recommended loading dose, respectively).