The oral GnRH antagonists, a new class of drugs in gynecology: from pharmacokinetics to possible clinical applications
Marta Barretta, M. Vignali, Antonio La Marca, Giovanni Grandi
Abstract
INTRODUCTION: In ovarian steroid-dependent diseases such as uterine fibroids, endometriosis and adenomyosis, oral GnRH antagonists have emerged as new therapeutic alternatives. These oral GnRH antagonists offer key advantages, including oral administration, dose-dependent estrogen suppression and rapid reversibility. AREAS COVERED: This review examines the pharmacological, clinical and therapeutic profiles of the latest non-peptide oral GnRH antagonists, through an analysis of clinical evidence and randomized clinical trials, to provide a comprehensive and up-to-date overview of their clinical applications and potential benefits. EXPERT OPINION: The clinical trials examined demonstrated significant efficacy in reducing heavy menstrual bleeding in women with fibroids and pelvic pain in women with endometriosis, with more than 70% of patients achieving primary endpoints. The use of add-back therapy minimized bone mass density loss, ensuring long-term safety. Adverse events were dose-dependent but generally well tolerated. In our opinion, the strength of oral GnRH antagonists lies in their pharmacological properties. Oral administration increases convenience, allows adjustable dosing and ensures a dose-dependent effect. These drugs provide an immediate antagonistic effect without the flare-up phenomenon. Furthermore, they are expected to act on ectopic endometrial and smooth muscle cell receptors, potentially providing additional anti-proliferative effects. However, further research is needed: long term clinical trials must compare them with existing treatments.