Testing Different Amounts of the Combination of Drugs M1774 and ZEN-3694 for the Treatment of Recurrent Ovarian and Endometrial Cancer

This study is testing two experimental drugs (M1774 and ZEN-3694) in people with recurrent ovarian or endometrial (uterine) cancer. Researchers are testing different dose combinations to find the safest and most effective approach, particularly in cancers with or without a gene called ARID1A. **You may be eligible if...** - You are 18 or older with recurrent clear cell, endometrioid ovarian cancer, or endometrial cancer, or recurrent platinum-resistant high-grade serous ovarian cancer - You have received 1 to 3 prior chemotherapy regimens - Your cancer is measurable on imaging - Your blood counts, kidney, and liver function meet required levels - You are able to swallow oral medications **You may NOT be eligible if...** - You are currently taking another investigational drug - You have previously received ATR, ATM, BET, or PI3K inhibitor drugs - You are taking proton pump inhibitors (like omeprazole) that cannot be stopped - You have serious heart conditions or prolonged QT interval on your heart tracing (ECG) - You have a history of serious DNA repair disorders - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.