Testing the Addition of Sunitinib Malate to Lutetium Lu 177 Dotatate (Lutathera) in Pancreatic Neuroendocrine Tumors

PRIMARY OBJECTIVE: I. To evaluate the safety and maximum tolerated dose (MTD) for the combination of sunitinib malate with lutetium Lu 177 dotatate in metastatic unresectable pancreatic neuroendocrine tumors (NETS). SECONDARY OBJECTIVES: I. To observe and record anti-tumor activity. II. To assess objective response rate (ORR) of the combination by the Response Evaluation Criteria in Solid Tumors (RECIST) version (v)1.1. III. To assess progression-free survival (PFS) and overall survival (OS) of the combination. IV. To determine the duration of response (DOR) from the combination. V. To determine lutetium Lu 177 dotatate dosimetry in the combination. VI. To associate somatostatin receptor (SSR) positron emission tomography (PET) triage imaging with lutetium Lu 177 dotatate dosimetry. VII. To assess the correlation of chromogranin A (CgA) with disease response in patients being treated with lutetium Lu 177 dotatate. OUTLINE: This is a dose-escalation study of sunitinib malate followed by a dose-expansion study. Patients receive sunitinib malate orally (PO) daily (QD) from day 1 of lutetium 177 dotatate therapy to 28 days after the last dose of lutetium 177 dotatate in the absence of unacceptable toxicity. Patients also receive lutetium Lu 177 dotatate intravenously (IV) over 30 minutes on day 1 of each cycle. Cycles repeat every 8 weeks (Q8W) for 4 cycles in the absence of unacceptable toxicity. Patients undergo a computed tomography (CT) scan and/or magnetic resonance imaging (MRI) throughout the trial. Patients also undergo a SSR PET/CT scan during screening and blood sample collection on study. After completion of study treatment, patients are followed for up to 4 weeks.