First-line Carboplatin and Paclitaxel in Combination With Pembrolizumab, Followed by Maintenance Pembrolizumab With or Without Nesuparib, in Patients With Newly Diagnosed Advanced or Recurrent MMR-proficient (pMMR) Endometrial Cancer

This study tests whether adding a PARP inhibitor (nesuparib) to standard maintenance immunotherapy (pembrolizumab) after chemotherapy improves outcomes for women with advanced or recurrent endometrial (uterine) cancer that has a normal DNA repair system (called MMR-proficient or pMMR). **You may be eligible if...** - You are a woman aged 19 or older - You have advanced (stage III–IV) or recurrent endometrial cancer confirmed by biopsy - Your tumor has been tested and found to be MMR-proficient (normal DNA repair) - You have not had chemotherapy for advanced disease before (or completed it as an adjuvant treatment at least 12 months ago) - You have good overall health (ECOG score 0–2) - Your blood counts, liver, kidney, and thyroid function are at acceptable levels **You may NOT be eligible if...** - You have previously been treated with a PARP inhibitor - Your tumor is MMR-deficient (abnormal DNA repair system) - You have active brain metastases (some treated cases may be acceptable) - You have a serious autoimmune condition, severe infection, or significant heart problems - You have HIV, active hepatitis B or C, or a history of myelodysplastic syndrome - You are pregnant or breastfeeding - You have had an organ transplant Talk to your doctor to see if this trial is right for you.