Progestins for the Treatment of Endometrial Cancer or Precancers of the Uterus Before Surgery, The Pro-Window Trial

This phase II trial tests compares the effect of progestins, megestrol acetate to micronized progesterone, in treating patients with endometrial cancer and precancers of the uterus (atypical endometrial hyperplasia) before surgery. Progestins, similar to the natural hormone progesterone, are approved drugs used in birth control and hormone replacement pills, and some can treat uterine endometrial cancers. In the initial comparison of this rotating umbrella trial, megestrol acetate, a progestin, will be compared to micronized progesterone, a form of natural progesterone that is a hormone produced by body normally. Hormone therapy using megestrol acetate and micronized progesterone may be effective in treating patients with endometrial cancer or atypical endometrial hyperplasia before surgery, and understanding the tissue effects of each agent on the malignant endometrium will uncover novel mechanistic and biomarker data to understand how best to advanced hormone therapy for endometrial cancer.

NCT Number	NCT07436793
Lead Sponsor	New Mexico Cancer Research Alliance Collaborators: University of New Mexico Cancer Center, National Cancer Institute (NCI)
Conditions	Endometrial Endometrioid Adenocarcinoma, Endometrial Hyperplasia
Enrollment	140 participants
Start Date	2026-06-15
Primary Completion	2030-06-30 (estimated)
Study Completion	2031-06-30 (estimated)
Updated on ClinicalTrials.gov	2026-07-02