Abstract
Immune checkpoint inhibitors (ICIs) are revolutionizing the treatment of many cancers and have demonstrated their potential as 'cancer terminators'. However, ICI treatment also has constraints, such as its immune-related adverse events (irAEs) and therapeutic resistance. These drawbacks are gradually being overcome through better knowledge of the immune system, history of disease, duration of treatment, combinational drug regimes, adequate biomarkers, and effective patient response monitoring. In this review, we discuss the present ICI therapy landscape and its therapeutic outcomes for various diseases. We also highlight biomarkers related to the ICI response.