This is a multicentre, randomized, double-blind, parallel-controlled integrated phase I/III clinical study to evaluate the similarity in efficacy, safety, PK profile, and immunogenicity of HLX17 vs. Keytruda®( US- and EU-sourced) in the first-line treatment of advanced non-squamous non-small cell lung cancer.

This study includes three treatment groups. Patients will be randomly assigned at a 2:1:1 ratio to the HLX17, US-sourced Keytruda® and EU-sourced Keytruda® group to receive the treatment of IMPs in combination with Carboplatin Plus Pemetrexed until disease progression, initiation of new anti-tumor therapy, withdrawal of informed consent form, death, unacceptable toxicity, or up to 17 cycles (whichever occurs first).

Inclusion Criteria:

• Histologically or cytologically confirmed diagnosis of stage IV inoperable to surgery or radiotherapy (AJCC 8th edition) non-squamous NSCLC.
• Without any tumor activating EGFR mutation or ALK or ROS1 gene rearrangement.
• Have not received prior systemic treatment for their advanced/metastatic NSCLC.
• At least one measurable lesion as assessed by IRRC based on RECIST v1.1.
• Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Status.
• Have adequate organ function.

Exclusion Criteria:

• Subjects with NSCLC of other histopathological types, such as mixed adenosquamous carcinoma, and subjects with small cell lung cancer or neuroendocrine carcinoma.
• Subjects with other active malignancies within 5 years or at the same time prior to screening.
• Active central nervous system metastases.
• Known interstitial pneumonia, pneumoconiosis, radiation pneumonitis, drug-related pneumonitis, and severe lung function abnormalities that may impede the investigators' diagnosis and management of drug-related pulmonary toxicity.
• Known active or suspected autoimmune diseases.
• History of immunodeficiency, including HIV antibody positive, active hepatitis B; or hepatitis C virus infections.
• Have received pembrolizumab or any other immune checkpoints inhibitors (PD-1, PD-L1, CTLA4, etc.) before screening.
• Pregnant or breastfeeding female.
• The investigator has a clear reason to believe that participation in this study would be detrimental to the subject.