Pharmacokinetic Similarity Between ABP 234 and Keytruda® (Pembrolizumab)

Inclusion Criteria: * Males and females ≥ 18 years of age. * Pathological diagnosis of non-squamous NSCLC. * Stage IB (T2 ≥ 4 cm), II, or IIIA NSCLC after complete surgical resection and received platinum-based chemotherapy. * For programmed death-ligand 1 (PD-L1) testing, tumor tissue from the resected site of disease must be sent, received, and analyzed for biomarkers. * Treated with platinum-based chemotherapy: 1. Chemotherapy must have begun within 12 weeks after the resection surgery. 2. The last chemotherapy dose must have been completed at least 3 weeks and no more than 12 weeks before the participant is randomized. * Eastern Cooperative Oncology Group (ECOG) performance status score 0 or 1. * Epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), and ROS-1 negative. * Have adequate organ function as indicated by laboratory values. * Absence of severe comorbidities that in the opinion of the investigator might hamper participation in the study and/or treatment administration. * Participants must sign approved informed consent form (ICF). Exclusion Criteria: * Evidence of disease. * Prior treatment with anti-programmed cell death protein 1 and anti-PD-L1/2 modulating agents in adjuvant setting. * History or presence of immune-mediated disorders. * Participants with type 1 diabetes mellitus, residual hypothyroidism due to autoimmune thyroiditis only requiring hormone replacement, or skin disorders not requiring systemic treatment are permitted to enroll. * Participant has positive screen for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb) or hepatitis C (HCV). * History of congenital immunodeficiency diseases, prior allogeneic stem cell transplantation, or organ transplantation. * History of any other malignancy other than NSCLC within 5 years prior to screening, except for appropriately treated carcinoma in situ of the cervix, nonmelanoma skin carcinoma, papillary thyroid cancer treated with surgery, etc. * Known clinically significant history of liver disease consistent with Child-Pugh Class B or C, including active viral or other hepatitis virus, current alcohol abuse or cirrhosis. * Surgery or chemotherapy-related toxicity not resolved to grade 1 with the exception of grade ≤ 2 alopecia, fatigue, neuropathy, and lack of appetite/nausea. * Woman of childbearing potential who is pregnant or is breast feeding. * Woman of childbearing potential who is not consenting to use highly effective methods of birth control. * Man with a partner of childbearing potential who does not consent to use highly effective methods of birth control. * Participant has known hypersensitivity to monoclonal antibodies or to any of the excipients of the investigational product (IP). * Active cardiac disease or history of cardiac dysfunction, that in the judgment of the investigator would place the participant at additional risk when participating in the study. * Has a history of (non-infectious) pneumonitis/interstitial lung disease that required steroids or has current neumonitis/interstitial lung disease. * Live vaccine therapy within 4 weeks prior to IP administration. * Participation in another investigational drug study within 30 days prior to IP administration.