The goal of this clinical trial is to evaluate QL1706 plus bevacizumab with or without chemotherapy in patients with PD-L1-negative, locally advanced or metastatic non-squamous non-small cell lung cancer (NSCLC) previously treated with immune checkpoint inhibitors (ICIs). The primary objectives are:

To assess the efficacy and safety of QL1706 combined with bevacizumab (± chemotherapy) in this population.

Eligible patients with PD-L1-negative, locally advanced or metastatic non-squamous NSCLC who progressed after prior PD-1/PD-L1 inhibitor therapy will be assigned to one of two treatment arms at the investigator's discretion:

Arm 1: QL1706 + bevacizumab + chemotherapy (target enrollment: 67 subjects). Single-agent chemotherapy (selected from regimens not previously received) will be administered, with options including nab-paclitaxel, pemetrexed, or docetaxel.

Arm 2: QL1706 + bevacizumab (target enrollment: 10 subjects).

Inclusion Criteria:

1. Signed an informed consent form
2. Patients aged ≥18
3. Histologically or cytologically confirmed stage III or IV non-squamous non-small cell lung cancer (NSCLC) per the American Joint Committee on Cancer (AJCC) 8th Edition staging system
4. at least one measurable lesion according to RECIST 1.1 criteria
5. ECOG PS 0-1.
6. Subjects must have adequately documented disease progression following prior treatment with PD-1/PD-L1 inhibitors (administered as monotherapy or in combination with chemotherapy)

8. The most recent tumor tissue sample prior to the first dose of the study drug demonstrated PD-L1 TPS <1% 9. appropriate organ function

Exclusion Criteria:

1. Known presence of sensitizing mutations in EGFR, EGFR exon 20 insertions, ALK fusions, ROS1 fusions, RET fusions, NTRK fusions, BRAF V600E mutations, MET exon 14 skipping mutations, or HER2 sensitizing mutations (for other genetic alterations, eligibility will be determined by the Biomarker Committee on a case-by-case basis).
2. Patients with symptomatic, neurologically unstable central nervous system (CNS) metastases, or CNS diseases that require increased steroid doses to control
3. Prior lines of systemic anti-tumor therapy ≥ 2.