Endometrial histology following 1 year of a continuous daily regimen of levonorgestrel 90 micro g/ethinyl estradiol 20 micro g

Julia V. Johnson, University of Massachusetts Medical School
Gary S. Grubb, Wyeth Research
Ginger D. Constantine, Wyeth Research

At the time of publication, Julia Johnson was not yet affiliated with the University of Massachusetts Medical School.

Abstract

OBJECTIVE: The objective of this study was to evaluate the effect of a continuous daily regimen of levonorgestrel (LNG) 90 micro g/ethinyl estradiol (EE) 20 micro g on endometrial histology.

METHODS: This was a substudy of a large phase 3 trial conducted in six sites in North America. Healthy and sexually active women aged between 18 and 49 years took LNG 90 micro g/EE 20 micro g daily for 1 year. Results from endometrial biopsies performed at pretreatment baseline and those after at least 6 months of treatment were compared. RESULTS: Of the 146 participants, 93 had a baseline biopsy and completed at least six pill packs. Before treatment, 56 subjects (60%) had an endometrial biopsy with findings classified as "weakly proliferative or proliferative." During the last on-therapy visit, 48 subjects (52%) had an endometrium categorized as "other," which included primarily an inactive or benign endometrium (n=42). No hyperplasia or malignancy was observed during the study.

CONCLUSION: The results of a 1-year continuous regimen of LNG 90 micro g/EE 20 micro g were shown to have a good endometrial safety profile.