The goal of this clinical trial is to compare the amount of study drug in patients' blood to confirm that SB27 works in the same way as EU and US sourced Keytruda in early or locally advanced non-small cell lung cancer (NSCLC) patients who underwent surgery and adjuvant chemotherapy. The main question it aims to answer is: • What the body does to the study drug, which is called pharmacokinetic Participants will receive investigational product (IP) administration every 3 weeks, maximum 18 cycles over about 51 weeks and blood sample will be collected. Researchers will compare 3 medicines (SB27, EU sourced Keytruda, and US sourced Keytruda) to see if SB27 works in the same way as EU and US sourced Keytruda.