A Study to Compare the Pharmacokinetics, Efficacy, Safety, and Immunogenicity of Pembrolizumab (SB27, EU Sourced Keytruda, and US Sourced Keytruda) in Subjects With Stage II-IIIA NSCLC Following Complete Resection and Adjuvant Platinum-based Chemotherapy

A Phase I, Randomised, Double-blind, Three-arm, Parallel Group, Multicentre Study to Compare the Pharmacokinetics (PK), Efficacy, Safety, and Immunogenicity of Pembrolizumab (SB27, European Union [EU] Sourced Keytruda, and the United States of America [US] Sourced Keytruda) in Subjects With Stage II-IIIA Non-small Cell Lung Cancer Following Complete Resection and Adjuvant Platinum-based Chemotherapy

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.

Inclusion Criteria:

• Male or female aged 18 years or older
• Diagnosed as NSCLC stage II-IIIA (staging should be confirmed after surgery)
• Have completely removed all of the cancer from the body surgically
• Have been received 3 or 4 cycles of platinum-based chemotherapy after surgery

Exclusion Criteria:

• Have received anti-cancer therapy before surgery
• Have or had autoimmune disease in past 5 years