Therapy of neuroendocrine tumors with the radioactively labeled somatostatin receptor antagonist 161Tb-DOTA-LM3 (Beta Plus study)

Criteria for participation in trial
Patient with diagnosed and metastatic hormonally active or inactive GEP-NEN (Grade 1 or 2) Absence of a curative surgical option At least 2 measurable lesions based on RECIST v.1.1 (minimum tumor diameter 1 cm) 68Ga-DOTATOC/-TATE PET/CT Indication for PRRT Patient age over 18 years Contraception for women of childbearing age during and up to 6 months after treatment ECOG ≤ 2 Leukocytes ≥ 3*10^9/L Hemoglobin ≥ 90 g/L Platelets ≥ 90*10^9/L Estimated GFR ≥ 50 ml/min or creatinine < 150 μmol/l Albumin > 25g/L ALT, AST, AP: ≤ 5 times the increase over the standard value Bilirubin ≤ 2 times the increase over the standard value (BASEC)

Exclusion criteria
Known intolerance to 177Lu, 161Tb, DOTA, TOC, LM3, somatostatin analogs or to the components of 177Lu-DOTATOC or 161Tb-DOTA-LM3 Bone/bone marrow metastases in the LWS leading to impairment of the calculation of the bone marrow dose Current acute infection or serious infection within the last 4 weeks prior to Visit 1 Treatment with another investigational medical product within the last 60 days prior to Visit 1 Previous or planned administration of a therapeutic radiopharmaceutical within 8 half-lives of the radionuclide of the radiopharmaceutical used, even during the ongoing study Radiotherapy involving the bone marrow in the last 3 months prior to study inclusion Chemotherapy in the last 4 weeks prior to study inclusion Pregnancy or breastfeeding Uncontrolled significant medical, psychiatric, or surgical conditions or laboratory findings that may compromise patient safety or limit the achievement of study objectives and assessments. Mental conditions preventing the patient from understanding the nature, scope, and possible consequences of the study and/or an uncooperative attitude of the patient Current history of other malignancies than NET within 5 years prior to study enrollment, except for completely resected non-melanocytic skin cancer or carcinoma in situ of the cervix (BASEC)