Comparing Retreatment of 177Lu-DOTATATE PRRT Versus the Usual Treatment in Patients With Metastatic Unresectable Gastroenteropancreatic Neuroendocrine Tumors, NET RETREAT Trial

This phase II trial compares the effect of retreatment with 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) to the usual approach of treatment with everolimus, sunitinib, or cabozantinib in patients who have previously received 177Lu-DOTATATE for gastroenteropancreatic neuroendocrine tumor (GEPNET) that has spread from where it first started (primary site) to other places in the body (metastatic) and that cannot be removed by surgery (unresectable). PRRT is a type of radiation therapy for which a radioactive chemical is linked to a peptide (small protein) that targets tumor cells. When this radioactive peptide is injected into the body, it binds to a specific receptor found on some tumor cells. The radioactive peptide builds up in these cells and helps kill the tumor cells without harming normal cells. In this trial 177Lu-DOTATATE is used for PRRT. 177Lu-DOTATATE PRRT may increase the length of time until worsening of the GEPNET compared to the usual approach. Everolimus is in a class of medications called kinase inhibitors. It is also a type of angiogenesis inhibitor. Everolimus works by stopping tumor cells from reproducing and by decreasing blood supply to the tumor cells. Sunitinib and cabozantinib, block certain proteins, which may help keep tumor cells from growing. They may also prevent the growth of new blood vessels that tumors need to grow. Sunitinib malate is a type of tyrosine kinase inhibitor and a type of antiangiogenesis agent. Retreating with 177Lu-DOTATATE may work better than everolimus, sunitinib or cabozantinib in shrinking or stabilizing tumors in patients with metastatic and unresectable GEPNET who were previously treated with 177Lu-DOTATATE.