Mitchell D. Creinin : Estetrol in contraception

Описание: Conférence donnée le Samedi 23 avril 2022 à 9h30 à la Séance en l'honneur du Professeur Jean-Michel Foidart : Estetrol, a Human Fetal Estrogen from Molecular Biology to the Clinics par Mitchell D. CREININ, M.D. (University of California Davis Sacramento CA, USA)

Estetrol, a native estrogen with selective action in human tissues, has been developed for clinical use with initial phase 1 clinical trials starting in 2005. A robust Phase 2 program evaluated different dose of estetrol, in combination with both levonorgestrel and drospirenone, to identify a target product. Phase 2 studies assessed cycle control, ovarian function, and safety parameters, clearly demonstrating the benefit of an estetrol/dropirenone combination. Both of these hormones are relatively “neutral” on the liver and kidney, resulting in different outcomes during phase 2 studies as compared to ethinyl estradiol containing combined contraceptives. Of particular interest are the novel findings related to hemostatic parameters; for the first time, investigators could study differences in coagulation markers when only the estrogen differed, giving more insight into the impact of various hormone on clotting risk. The findings suggest a potentially lower risk of venous thromboembolic events (VTEs) as compared to ethinyl estradiol products. The phase 3 program included two parallel, multicenter studies – one performed in Europe and Russia, and the other in the U.S. and Canada. Enrolling more than 3,600 participants, the trials demonstrated high contraceptive efficacy, no difference in pregnancy rates between obese and non-obese participants, excellent cycle control, and a low adverse event profile. The only adverse event that resulted in discontinuation with a rate exceeding 1% was bleeding complaints, with a low rate of 2.8%. The phase 3 study also provided the opportunity for the first large population evaluation of VTE events. With only one VTE occurring in the two studies, for which 4 or more would have been expected, we begin to see the potential benefits of this combination come to fruition. Still, population-based phase 4 studies are still needed to confirm the low VTE risk with estetrol/drospirenone oral contraceptive.