The phase 1/2 clinical study includes three stages: Phase 1 dose escalation, phase 1 PK expansion and phase 2 cohort expansion：
* Phase 1: Assesse safety, tolerability, PK, immunogenicity and preliminary efficacy of QLS5133 in advanced solid tumors. Phase 1 dose escalation will use ATD + BOIN, the maximum sample size for each dose group is 12. For Phase 1 PK expansion, 1 to 4 appropriate doses will be selected. After the DLT observation period in the selected dose group up to 12 subjects (including those subjects in the dose escalation stage) can be further enrolled for PK expansion.
* Phase 2: Evaluates QLS5133's anti-tumor efficacy in subjects with advanced solid tumors. at least 2 dose groups will be expanded.