Investigation of the Anti-tumor Effect of 2X-121 in Patients With Recurrent, Advanced Ovarian Cancer

This study is testing an experimental oral drug called 2X-121 — a PARP inhibitor that blocks a protein cancer cells use to repair their DNA — in women with advanced ovarian cancer that has stopped responding to standard platinum chemotherapy. **You may be eligible if...** - You are 18 or older - You have ovarian, fallopian tube, or peritoneal cancer confirmed by biopsy (high-grade serous or endometrioid type) - Your cancer no longer responds to platinum chemotherapy — progressed within 6 months, or you are ineligible for platinum - You have received no more than one prior treatment since your cancer became platinum-resistant - You have measurable disease visible on CT or MRI scan **You may NOT be eligible if...** - You have already received more than one line of treatment after becoming platinum-resistant - You have conditions affecting blood counts, kidney, liver, or heart function - You are pregnant or breastfeeding - You have had a prior bone marrow transplant or certain prior therapies Talk to your doctor to see if this trial is right for you.