Study to Test the Safety and How Radium-223 Dichloride an Alpha Particle-emitting Radioactive Agent Works in Combination With Pembrolizumab an Immune Checkpoint Inhibitor in Patients With Stage IV Non-small Cell Lung Cancer With Bone Metastases

The purpose of the study is to determine the safety and test the efficacy of the combination of radium-223 dichloride and pembrolizumab in patients with stage IV non-small cell lung cancer (NSCLC) with bone metastases who either have not received any systemic therapy for their advanced disease or have progressed on prior immunologic checkpoint blockade with antibodies against the programmed cell death protein-(ligand) 1 (PD-1/PD-L1). In this study researchers want to measure tumor shrinkage in response to treatment and how long that shrinkage lasts and gather information on safety. Pembrolizumab is an immunologic checkpoint blocker that promotes an immune response against the tumor. Radium-223 dichloride is an alpha particle-emitting radioactive agent which kills cancer cells.