Additional Study Information: The purpose of this study is to assess the overall safety and efficacy (how well the drug works) of study drug M7824 in the treatment of unresectable, non-small cell lung cancer. Another purpose is to determine whether use of the study drug in combination with chemoradiation (chemotherapy plus radiation therapy) followed by the study drug will result in greater survival and tumor reduction. The study drug is thought to work by blocking two pathways in tumors that normally allow the tumors to resist attack by the immune system, thus allowing them to grow and spread. By blocking these two pathways, the study drug allows the body's immune system to more effectively attack the tumors and prevent the tumors from spreading. You will randomly be divided into one of two groups for this study. One group will receive either the study drug plus with chemoradiation therapy, followed by more of the study drug, or the FDA approved drug Durvalumab combined with chemoradiation therapy, followed by more Durvalumab.