Nivolumab and 177Lu-DOTA0-Tyr3-Octreotate for Patients With Extensive-Stage Small Cell Lung Cancer

This research study is being done to assess the safety and tolerability of study drugs, 177Lu-DOTA0-Tyr3-Octreotate (Lutathera) and nivolumab in subjects with small cell lung cancer or advanced or inoperable neuroendocrine tumor of the lung that has overexpressed somatostatin receptors (SSRT). Lutathera is an investigational radioactive agent that targets tumor cells that express SSRT. Nivolumab is an investigational agent that targets and inhibits a pathway that prevents your immune system from effectively fighting your cancer. The combination of these 2 study drugs is investigational. The term "Investigational" in this context means that the drugs have not been approved for clinical use by the US Food and Drug Administration (FDA). Giving Lutathera and nivolumab together may increase the effectiveness of this therapy. We first need to find out the highest dose of Lutathera that can be given safely together with nivolumab. This study will be the first study to test giving Lutathera together with nivolumab. Once we have found the highest dose of Lutathera that can be given with nivolumab, we will treat more patients with this combination to determine how effective it is. The purposes of this study are: To find the highest doses of Lutathera that can be given with nivolumab without causing severe side effects. To find out the side effects seen by giving Lutathera at different dose levels with nivolumab. To determine if the amount of something in your tumor called PD-L1 makes you more likely to have a response to the combination of Lutathera and nivolumab.