Endocrine Abstracts

State of the art: In pharmacology, human chorionic gonadotropin (hCG) is considered equivalent to luteinising hormone (LH) since both act on the same receptor. Thus, when testicular function needs to be clinically restored (i.e. in case of hypogonadotropic hypogonadism [HH]), hCG is used instead of LH. However, growing evidences showed LH and hCG activate different molecular pathways and offer different outcomes in women undergoing assisted reproduction. The different action between LH and hCG is still not evaluated in men.

Aim of the study: To assess the pharmacodynamics of recombinant LH in HH men, comparing recombinant LH (Luveris®) to the gold standard approach, i.e. hCG (Gonasi HP®).

Study design: A multicenter, longitudinal, randomized, open label, phase II, ‘non-inferiority’ clinical trial was designed. Endpoints will be testosterone serum levels and drug safety. 32 men with acquired HH will be enrolled and randomized (1:1) to study group treated with Luveris or to control group treated with Gonasi. In both groups, increasing drug doses will be administered (75, 150, 225, 300 IU daily for LH and 500, 1000, 1500 and 2000 IU two times weekly for hCG). Both treatments will be performed for 8 weeks, during which the patient will be evaluated twice weekly, followed by a 4-week washout period. Testosterone and its metabolite will be evaluated at the end of study using the gold standard mass spectrometry methodology.

Expected Results: We expect to describe for the first time the pharmacodynamics of both LH and hCG chronically administered in men, creating a dose-response curve for both compounds. Moreover the clinical hCG dosage is still empirical, thus we will recognize the best treatment regimen to restore normal testosterone levels in HH, for both LH and hCG treatment. This study is preliminary to further studies assessing LH in hypogonadal and/or infertile patients.

Current study state: The study started in March 2022 and we currently enrolled 3 HH patients.