Teverelix Trifluoroacetate

Teverelix trifluoroacetate is a decapeptide, gonadotropin‐releasing hormone antagonist that binds competitively and reversibly to gonadotropin‐releasing hormone receptors in the pituitary gland, resulting in immediate suppression of luteinizing hormone and follicle‐stimulating hormone, which in turn causes a very rapid decrease in testosterone production in the Leydig cells of the testes in men and in estradiol in the ovaries in women. This phase 1 clinical study was an open‐label, parallel‐design, single‐center, single‐dose study in older, healthy male subjects. Following injection, teverelix is released into the systemic circulation in a biphasic manner. An initial rapid phase is followed by a slow‐release phase thought to be due to the formation of a depot, which limits the diffusion of teverelix into the blood. The release characteristics differ significantly for the subcutaneous (SC) and intramuscular (IM) routes. Teverelix maximum concentration and exposure increased in an approximately dose‐proportional manner across the 60 to 120 mg SC doses. All 3 pharmacodynamic end points (luteinizing hormone, follicle‐stimulating hormone, and total testosterone) showed reductions that were more prolonged following the 90 mg IM administration compared to 90 mg SC administration.