SVV-001 With Nivolumab and Ipilimumab in Patients With Poorly Differentiated Neuroendocrine Carcinomas (NEC) or Well-Differentiated High-Grade Neuroendocrine Tumors (NET)

The purpose of this study is to determine: 1. The highest dose of the trial intervention that targets neuroendocrine tumors and is tolerated by patients. 2. The highest frequency of dosing of the trial intervention that targets neuroendocrine tumors and is tolerated by patients. 3. The highest dose and frequency of dosing of the trial intervention that targets neuroendocrine tumors with at least the same degree of effectiveness and tolerability as currently available (standard of care) treatments for patients with neuroendocrine tumors.