Pembrolizumab With Liver-Directed or Peptide Receptor Radionuclide Therapy for Neuroendocrine Tumors and Liver Metastases

This pilot phase II trial studies how effective pembrolizumab and liver-directed therapy or peptide receptor radionuclide therapy are at treating patients with well-differentiated neuroendocrine tumors and symptomatic and/or progressive tumors that have spread to the liver (liver metastases). Immunotherapy with monoclonal antibodies, such as pembrolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Liver-directed therapies such as radiofrequency ablation, transarterial embolization, yttrium-90 microsphere radioembolization, and cryoablation may help activate the immune system in order to shrink tumors that are not being directly targeted. Peptide receptor radionuclide therapy is a form of targeted treatment that is performed by the use of a small molecule, which carries a radioactive component attached to a peptide. Once injected into the body, this small molecule binds to some specific sites on tumor cells called receptors and emit medium energy radiation that can destroy cells. Because this radionuclide is attached to the peptide, which binds receptors on tumor lesions, the radiation can preferably be targeted to the tumor cells in order to destroy them. Giving pembrolizumab in combination with liver-directed therapy or peptide receptor radionuclide therapy may work better than pembrolizumab alone.