Recurrent Endometrial Cancer

This is a pragmatic, non-inferiority randomized hybrid decentralized clinical trial. The goal of this study is to determine if one year of maintenance immunotherapy (anti-PD1 agent therapy; pembrolizumab or dostarlimab) is non-inferior to two years of maintenance therapy for patients with advanced/metastatic or recurrent endometrial cancer who have completed the standard course of cytotoxic chemotherapy plus anti-PD1 therapy (chemoimmunotherapy). Our hypothesis is that one year of maintenance therapy will be comparable, or statistically non-inferior, to two years of therapy. This question has clinical importance as there is not a clear optimal duration for maintenance immunotherapy in this setting, and checkpoint inhibitors are associated with their own unique toxicity profile (immune-related adverse events) and incremental costs to patients and the healthcare system at large. Patients who respond favorably to primary therapy and choose to enroll will be randomized (1:1) after completion of chemoimmunotherapy to one-year of maintenance anti-PD1 therapy (1-year arm) or to two-years of maintenance anti-PD1 therapy (2-year arm). The primary endpoint is progression-free survival (PFS) determined over the course of at least 3 years from randomization of patient follow up. Secondary endpoints are overall survival (OS) and incidence of immune-related adverse events (irAE). Finally, exploratory objectives include measuring differences in gut and vaginal microbial profiles and innate immune system (IIS) tumor profiles and correlation with clinical outcomes (PFS, OS).

The main purpose of this study is to: * Learn about the safety of ubamatamab and to find out what dose of ubamatamab can be given alone or with cemiplimab to patients with ovarian cancer or cancer of the uterus * The study will also look at the levels of ubamatamab and/or cemiplimab in the body and measure how well the body can remove the study drug(s). This is called pharmacokinetics * The study will also look at any signs that ubamatamab alone or with cemiplimab can treat recurrent advanced ovarian cancer or cancer of the uterus * To find out how safe and tolerable pretreatment is in combination with ubamatamab and to see how well it works to prevent or minimize Cytokine Release Syndrome (CRS)

The purpose of this study is to determine the efficacy and safety of Pembrolizumab in combination with Lenvatinib in recurrent, mismatch repair-proficient endometrial cancer after failure of first-line therapy with a platinum-based doublet chemotherapy and immunotherapy.

The purpose of this research study is to see if the study drugs abemaciclib and letrozole are effective and safe for participants with estrogen-receptor positive (ER+), mismatch repair proficient, tumor protein p53 (TP53) wild-type endometrial cancer. The names of the study drugs involved in this study are: * Abemaciclib (a type of cyclin-dependent kinase (CDK) inhibitor) * Letrozole (a type of aromatase inhibitor)