Additional Study Information: The purpose of this study is to compare the effects of using Sodium Cridanimod in combination with the progestin (hormone therapy) megestrol acetate. Hormonal therapy on its own is generally not aneffective treatment for endometrial cancer when there are not have enough progestin receptors on tumor cells. The addition of the study drug Sodium Cridanimod to the hormone therapy could increase the level of progestin receptors in your tumor tissue, allowing the progestin to work in shrinking the tumor size. An assessment of its safety is also a purpose of the study. or some women, hormone therapy on its own is not an effective treatment for endometrial cancer. This is because in these women the tumor tissue has no receptors or not enough receptors to respond to progesterone, commonly used for hormone therapy. The study drug used in this research could increase the level of progesterone receptors in tumor tissue, allowing the hormone therapy to potentially shrink the tumor size. Following are key inclusion criteria for eligibility. There are other criteria about your health that will need to be assessed to determine if you qualify for the study. Please contact Dr. Hou or her study staff to learn more about this study.