This study will compare the clinical activity of novel regimens (in combination or as single agents) to SoC in participants with relapsed/refractory advanced NSCLC. The study will be conducted in two parts. Part 1 is an open-label, optional, non-randomized part based on safety and pharmacokinetics/pharmacodynamics (PK/PD) evaluation intended to generate additional data to qualify novel regimens for the randomized study. Part 2 is a randomized, Phase II open-label part comparing the efficacy and safety of these novel regimens with SoC. Drug name mentioned as GSK4428859A (belrestotug) and EOS884448 are interchangeable for the same compound and will be referred to as GSK4428859A/EOS884448/belrestotug.
