A Study to Compare Uliledlimab Combined With Toripalimab, Toripalimab Monotherapy, and Pembrolizumab Monotherapy in Patients With Previously Untreated Locally Advanced Unresectable or Metastatic PD-L1- and CD73- Selected Non-Small Cell Lung Cancer

This is a Phase II/III, randomized, open-label, active-controlled, multicenter study to compare intravenous uliledlimab combined with toripalimab, toripalimab monotherapy, and pembrolizumab monotherapy in patients with previously untreated locally advanced unresectable or metastatic PD-L1-positive (tumor proportion score \[TPS\] ≥ 1%) and CD73-positive (TC/IC \> 30%; TC/IC defined as the higher of either the proportion of CD73-positive tumor cells or the proportion of CD73-positive immune cells at any intensity \[IHC1+ or above\]) NSCLC who are not suitable for targeted therapies such as EGFR, ALK, etc. The number of enrolled subjects with PD-L1 TPS ≥ 50% will be limited to approximately 60% of the total sample size to reflect the natural prevalence of advanced NSCLC. Patients who have received adjuvant or neoadjuvant therapy other than immune checkpoint inhibitor treatments are allowed to participate in this study, provided that such treatments have been completed at least 12 months prior to the occurrence of recurrence or metastasis. During the screening period, tumor samples will be collected in advance and tested by the central laboratory for PD-L1 expression levels using the PD-L1 IHC 22C3 pharmDx assay and CD73 expression levels using the CD73 antibody assay (immunohistochemistry). Previous PD-L1 testing results obtained using the PD-L1 IHC 22C3 pharmDx assay will be accepted. Patients with PD-L1 positive expression (TPS ≥ 1%) and high CD73 expression (TC/IC \> 30%) will meet the inclusion criteria. Patients who do not meet the eligibility criteria as judged by the investigator may be re-screened once. Patients with non-squamous NSCLC will be required to confirm the absence of EGFR-sensitive mutations or ALK fusion; patients with unknown EGFR and ALK expression status will be required to undergo testing and provide clinical laboratory test results prior to study enrollment, and may be enrolled after relevant driver gene mutations are ruled out. Meanwhile, patients with other definite actionable driver gene alterations (such as: ROS1 fusions, RET fusions, NTRK1/2/3 fusions, BRAF V600E mutations, MET14 exon skipping mutations, etc.) will be excluded from this study. Controversial cases with actionable gene mutations will be submitted to the study expert panel for joint decision. This study includes Phase II and Phase III stages. Approximately 150 subjects will be enrolled in the Phase II stage. Based on the evaluation of the efficacy, safety, PK, and PD results of the Phase II study, a decision will be made on whether to proceed to the Phase III study. Approximately 300 subjects will be enrolled in the Phase III stage.