Genomic Instability as a Biomarker of Response in Non–Small Cell Lung Cancer: Secondary Analysis of CheckMate 026

Lung cancer is one of the most common and deadly cancers worldwide, affecting millions of people each year. Our immune system can sometimes recognize and attack cancer cells, and certain treatments called immunotherapies help strengthen this response. However, not all patients benefit equally from immunotherapy, and finding reliable ways to predict who will respond best is a major challenge in cancer care.

We will focus on two important features of how cancer cells become unstable over time. The first is called Tumor Mutation Burden (TMB), which refers to the total number of genetic changes, or mutations, that occur in a tumor’s DNA (the molecule that carries our genetic information). A high TMB may make the cancer more recognizable to the immune system. The second feature is Copy Number Alterations (CNA), which are large-scale changes in the number of copies of certain genes within cancer cells. These changes can help tumors hide from the immune system and make treatment less effective. Although both TMB and CNA describe genetic instability, they represent different ways that cancer develops.

In this research, we will analyze data from the CheckMate 026 clinical trial, which tested immunotherapy in people with non-small cell lung cancer. Using this existing data, we will study whether combining TMB and CNA gives a clearer picture of which patients are most likely to benefit from immunotherapy than looking at either marker alone.

We will conduct a secondary analysis, meaning that we will use data already collected from the CheckMate 026 study rather than recruiting new patients. We will use statistical methods to compare patient outcomes and assess whether the combination of TMB and CNA can predict who responds best to treatment.

By improving how we identify patients who are more likely to benefit from immunotherapy, we hope this research will help doctors personalize treatment decisions. In the long term, our findings could contribute to better outcomes and fewer unnecessary treatments for people living with non-small cell lung cancer.