A Study to Compare Pharmacokinetics, Efficacy, Safety, and Immunogenicity of MB12 (Proposed Pembrolizumab Biosimilar) to Keytruda® in Non-small Cell Lung Cancer (BENITO Study)

Inclusion Criteria:

1. Adult male/female patients ≥18 years old at the time of signing the informed consentform (ICF).

2. Histologic or cytologic diagnosis of advanced NSCLC, stage IV (defined by the 8thedition of the Tumor Node Metastasis [TNM] classification), with no EGFR sensitizing (activating) mutation or ALK translocation, and who have not received prior systemictreatment for metastatic NSCLC. In those patients in whom the pleural or pericardialeffusion is the only location of metastatic disease, confirmation of its malignantetiology is required.

3. At least 1 radiographically measurable lesion according to response evaluationcriteria in solid tumors (RECIST) 1.1.

4. Known status of PD-L1 expression.

5. Performance based on the Eastern Cooperative Oncology Group (ECOG) performancestatus ≤1.

6. Adequate hepatic, renal, hematologic, endocrine, and coagulation function.

Exclusion Criteria:

1. Predominantly squamous cell histology NSCLC. Mixed tumors will be categorized by thepredominant cell type; if small cell elements are present, the patient is noteligible.

2. Known history of central nervous system metastases and/or carcinomatous meningitis.

3. Prior anti-programmed cell death (PD)-1, anti-PD-L1, anti-PD-L2, anti-CD137, oranti-cytotoxic T lymphocyte associated protein (CTLA)-4 therapy (includingipilimumab or any other antibody or drug that specifically targets co-stimulation ofT-cells or immune checkpoints).

4. Major surgery within 3 weeks of the first dose of study treatment.

5. Active autoimmune disease that has required systemic treatment in the last 2 years.

6. Contraindication and/or intolerance to the administration of pembrolizumab or knownsensitivity to any component of pembrolizumab.

7. Has a known sensitivity to any component of cisplatin, carboplatin, or pemetrexed.