Radioactive Drug (177Lu-DOTATATE) for the Treatment of Locally Advanced, Metastatic, or Unresectable Rare Endocrine Cancers

Inclusion Criteria: * Histological confirmation of PHPG, MTC, parathyroid or pituitary tumor * Locally advanced or distantly metastatic disease not amenable to surgery * Patients should have somatostatin receptor (SSTR)+ tumor as determined by 68Ga-DOTATATE PET/CT imaging. A measurable SSTR+ tumor is defined as having greater than or equal to 10 mm in diameter with uptake higher than or equal to liver and is qualitatively higher and distinguishable from background activity * In patients with multiple lesions (more than one) as determined by staging CT or MRI, the number of SSTR+ lesions should be more than or equal to the number of SSTR- lesions * Patients enrolled in cohorts 1-4 should have measurable disease defined by RECIST 1.1 * Patients enrolled in cohort 5 should have non-measurable disease as defined by RECIST 1.1 * Progressive disease per RECIST 1.1 as determined by the investigator within the 12 months preceding study enrollment * Radiographic assessment of all known disease sites, e.g., by computerized tomography (CT) scan, magnetic resonance imaging (MRI), bone scan as appropriate within 28 days before the first dose of (177)Lu-DOTATATE * Disease specific hormonal studies to assess abnormal hormonal secretion within 28 days before the first dose of (177)Lu-DOTATATE. These studies may include the following: plasma metanephrines and catecholamines for PHPG, calcitonin and CEA for MTC, prolactin for malignant prolactinomas, IGF-1 for growth hormone secreting maligna…