The Phase 1 trial includes Phase 1a (dose-escalation) and Phase 1b (dose-expansion):

• Phase 1a: Assesses safety, tolerability, PK, and preliminary efficacy of QLS5132 in advanced solid tumors using ATD + BOIN, given IV every 3 weeks. Up to 12 subjects may be enrolled in promising dose levels.
• Phase 1b: Evaluates QLS5132's anti-tumor efficacy in specific CLDN6-positive solid tumors, including ovarian cancer, NSCLC, gastric cancer, and others. Expansion studies at 1~3 selected dose levels follow successful Phase 1a results.

Inclusion Criteria:

• Advanced solid tumors;
• Measurable disease, per RECIST v1.1;
• Eastern Cooperative Oncology Group (ECOG) performance status 0-1;
• Adequate organ function;
• Recover from all reversible AEs from previous anti-tumor treatment (i.e., Grade ≤ 1, according to NCI-CTCAE v5.0), excluding alopecia (any grade) and Grade ≤ 2 neuropathy peripheral;

Exclusion Criteria:

• Previous treatment with drugs targeting CLDN6 (including ADCs), or any drug containing topoisomerase I inhibitors (including ADCs);
• Received prior chemotherapeutic, investigational, or other therapies for the treatment of cancer within 2 weeks with small molecule and within 4 weeks with biologic before the first dose of QLS5132;
• Progressive or symptomatic brain metastases;
• Serious, uncontrolled medical disorder, nonmalignant systemic disease, or active, uncontrolled infection;
• History of significant cardiac disease, or poorly controlled diabetes mellitus;
• History of recurrent autoimmune diseases;
• History of myelodysplastic syndrome (MDS) or AML;
• History of other active malignant tumors within 3 years before signing the informed consent form;
• If female, is pregnant or breastfeeding;
• Be allergic to any component of QLS5132 or its excipients.