Study to Evaluate the Safety and Preliminary Efficacy of 177Lu-OPS201 in NETs

Inclusion Criteria:

1. Written informed consent.
2. Patients of either gender, aged ≥ 18 years.
3. Women of childbearing potential (not surgically sterile or less than 2 years postmenopausal) must use a medically accepted method of contraception and must agree to continue use of this method for the duration of the study and for 6 months after the last dose. Acceptable methods of contraception include abstinence, or double contraception: steroidal contraceptive (oral, transdermal, implanted, and injected) in conjunction with a barrier method (intrauterine device, condom etc.).
4. Male patients must use a medically accepted method of contraception and must agree to continue use of this method for the duration of the study and for 6 months after the last activity administration.
5. Karnofsky performance score ≥ 60.
6. Life expectancy of at least 6 months.
7. Histologically confirmed diagnosis of -

   * unresectable GEP NET (Grade I and Grade II according to WHO classification (2010, Annex 01), functioning and non-functioning).
   * unresectable "typical lung carcinoid" or "atypical lung carcinoid" are acceptable (with the exception of Large Cell Bronchial Neuroendocrine Neoplasms and Small Cell Lung Cancers) (Caplin 2015).
   * malignant, unresectable pheochromocytoma or paraganglioma
8. Documentation of progressive disease based on RECIST v1.1 under prior anti-tumor therapy within 6 months of entry in the study (although the progression might have occurred more than 6 months before study entry). Patients should not have received further anti-tumor therapy once disease progression is documented. The images of this evaluation should be available for TGR evaluation.
9. In countries where sunitinib or everolimus are marketed, patients with GEP NET and lung NET will be progressive under this prior anti-tumor treatment for the respective indication. Patients not suitable for everolimus/sunitinib therapy according to a tumor board decision (or comparable local practice) may also be enrolled into the study. Patients having everolimus/sunitinib therapy should have a wash-out phase of ≥ 4 weeks before the first treatment.
10. Measurable disease based on RECIST v1.1.
11. Confirmed presence of somatostatin receptors on technically evaluable tumor lesions documented by a positive Somatostatin Receptor Scan performed within 6 months prior to enrolment in the study.
12. Calculated GFR ≥ 55 mL/min.
13. Blood test results as follows:

    * Leukocytes: ≥ 4\*10\^9/L
    * Erythrocytes: ≥ 3.5\*12\^9/L
    * Platelets: ≥ 100\*10\^9/L
    * Albumin: \> 30 g/L
    * ALT, AST, AP: ≤ 5 times ULN (upper limit of normal)
    * Bilirubin: ≤ 2 times ULN (2x 1.1 mg/dL)

Exclusion Criteria:

1. Known hypersensitivity to 177Lu, to DOTA, to JR11 or to any of the excipients of 177Lu-OPS201.
2. Any previous peptide receptor radionuclide therapy (PRRT).
3. Diagnosis of thymic NET.
4. Presence of active infection at screening or history of serious infection within the previous 6 weeks.
5. Administration of any other investigational medicinal product within 60 days prior to entry.
6. Prior or planned administration of a therapeutic radiopharmaceutical within 8 half-lives of the radionuclide including any time during the current study.
7. Any extensive radiotherapy ≤ 3 months before enrolment.
8. Chemotherapy ≤ 3 months before enrolment.
9. Nephrectomy, renal transplant or concomitant nephrotoxic therapy putting the subject at high risk of renal toxicity during the study as assessed by the investigator.
10. Pregnant or breast-feeding women: A pregnancy test will be performed at the start of the study for all female patients of childbearing potential (i.e. not surgically sterile or up to 2 years postmenopausal).
11. Any uncontrolled significant medical, psychiatric or surgical condition (active infection, unstable angina pectoris, cardiac arrhythmia, poorly controlled hypertension, poorly controlled diabetes mellitus \[HbA1c ≥9%\], uncontrolled congestive heart disease, etc.) or laboratory findings that, in the opinion of the investigator, might jeopardize the patient's safety or that would limit compliance with the objectives and assessments of the study. Note: the patient should be able to tolerate high volume load.
12. Current history of any malignancy other than NET within 5 years of enrolment except for fully -resected non-melanoma skin cancer or cervical cancer in situ. Current history of malignancy; patients with a secondary tumor in remission of \> 5 years can be included
13. Any mental condition rendering the patient unable to understand the nature, scope and possible consequences of the study, and/or evidence of an uncooperative attitude.