A Study of QLS5132 in Platinum-Resistant Recurrent Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

The goal of this interventional study is to compare the effectiveness and safety of QLS5132 monotherapy with investigator's choice of chemotherapy in participants with platinum-resistant recurrent epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer.

Inclusion Criteria: * Female participants aged ≥ 18 years. * Histologically confirmed epithelial ovarian cancer, fallopian tube cancer, or primary peritoneal cancer. * Platinum-resistant recurrent disease, defined as disease progression within 6 months (≤183 days) after the last platinum-based chemotherapy. * At least one measurable lesion per RECIST v1.1. * ECOG performance status of 0 or 1. * Expected survival ≥ 12 weeks. * Adequate organ and bone marrow function. * Negative pregnancy test for women of childbearing potential, and agreement to use effective contraception. Exclusion Criteria: * Prior treatment with CLDN6-targeting therapy or topoisomerase I inhibitors (e.g., topotecan, trastuzumab deruxtecan). * Active or untreated central nervous system (CNS) metastases or carcinomatous meningitis. (Patients with stable, treated CNS metastases may be eligible). * Clinically significant cardiovascular disease, including QTc ≥ 470 ms, LVEF \< 50%, or uncontrolled hypertension. * Active infections (e.g., HBV, HCV, HIV, tuberculosis, syphilis). * Active or history of autoimmune diseases requiring systemic treatment. * Severe liver disease (Child-Pugh B or C), uncontrolled diabetes, or other severe medical conditions that may interfere with the study.