The purpose of the current study is to evaluate the efficacy and safety of [177Lu]Lu-DOTA-TATE plus octreotide long-acting release (LAR) versus octreotide LAR alone in newly diagnosed patients with somatostatin receptor positive (SSTR+), well differentiated Grade1 and Grade 2 (G1 and G2) (Ki-67 <10%) advanced gastroenteropancreatic neuroendocrine tumors (GEP-NETs) with high disease burden

The study consists of a screening phase, a treatment phase and a follow-up phase. This study compares treatment with [177Lu]Lu-DOTA-TATE plus octreotide LAR and octreotide LAR only.

Inclusion Criteria:

• Presence of metastasized or locally advanced, unresectable (curative intent), histologically proven, well differentiated Grade 1 or Grade 2 (Ki-67 <10%) gastroenteropancreatic neuroendocrine tumor (GEP-NET) diagnosed within 6 months prior to screening.

• Participants with high disease burden in the Investigator's opinion. Following criteria should be used as the guiding principle for determining high disease burden:

  • Primary tumor or a metastatic lesion > 4 cm
  • More than one tumor or metastatic lesions measuring > 2 cm
  • Elevated alkaline phosphatase > 2.5 X upper limit of normal (ULN)
  • Presence of bone metastasis
  • Presence of peritoneal metastasis
  • Symptoms due to tumor volume such as pain, fatigue, weight loss, anorexia etc.
  • Symptoms due to hormone excess requiring active management
  • Additionally, participants who, in the Investigator's opinion, have high disease burden due to their disease characteristics not specified above could also be considered eligible.

• Participants ≥ 12 years of age.

• RLI somatostatin receptor (SSTR) uptake on all target lesions (defined by RECIST v1.1 criteria) at least as high as normal liver uptake assessed within 3 months prior to randomization. Any of the RLI modalities as available (some examples are listed below) can be used as per local practice:

  • [68Ga]Ga-DOTA-TOC PET/CT or PET/MRI
  • [68Ga]Ga-DOTA-TATE PET/CT or PET/MRI
  • [64Cu]Cu-DOTA-TATE PET/CT or PET/MRI
  • Somatostatin receptor scintigraphy (SRS) (planar and/or SPECT/CT) with [111In]In-pentetreotide
  • SRS (planar and/or SPECT/CT) with [99mTc]Tc-octreotide.

• Adequate bone marrow and organ function as defined by the following laboratory values prior to receiving the first study treatment:

  • White blood cell (WBC) count ≥ 2 x 109/L
  • Platelet count ≥ 75 x 109/L
  • Hemoglobin (Hb) ≥ 8 g/dL
  • Creatinine clearance > 40 mL/min calculated by the Cockcroft Gault method
  • Total bilirubin ≤ 3 x ULN
  • Potassium within normal limits. Potassium level of up to 6.0 millimoles per liter (mmol/L) is acceptable at study entry if associated with creatinine clearance within normal limits calculated using Cockcroft-Gault formula. Mild decrease (grade 1) below lower limit of normal (LLN) is acceptable at study entry if considered not clinically significant by Investigator.

• ECOG performance status 0-1.

• Presence of at least 1 measurable site of disease.

Exclusion Criteria:

• Prior administration of a therapeutic radiopharmaceutical for GEP-NET at any time prior to randomization in the study.
• Any previous therapy with interferons, mTOR-inhibitors, chemotherapy or other systemic therapies except somatostatin analogues (SSAs) of GEP-NET. If as per Investigator's opinion a participant is candidate for such therapies, such participant must not be enrolled.
• Participant who received more than 4 cycles of prior SSAs (e.g., octreotide long-acting release) are not eligible. In addition, any participant receiving treatment with short-acting octreotide, which cannot be interrupted for 24 h before the administration of [177Lu]Lu-DOTA-TATE, or any participant receiving treatment with SSAs, which cannot be interrupted for at least 4 weeks before the administration of [177Lu]Lu-DOTA-TATE.
• Documented RECIST v1.1 progression during previous SSA treatments for the current GEP-NET at any time prior to randomization.
• Any previous radioembolization, chemoembolization and radiofrequency ablation for GEP-NET.
• Any major surgery within 12 weeks prior to randomization in the study.
• Known brain metastases.
• Participant with known intolerance to CT scans with intravenous (i.v.) contrast due to allergic reaction or renal insufficiency. If such a participant can be imaged with MRI, then the participant would not be excluded.
• Hypersensitivity to any somatostatin analogues, to the Investigational Medicinal Products (IMPs) active substance or to any of the excipients.
• Active severe urinary incontinence, severe voiding dysfunction, or urinary obstruction requiring an indwelling/condom catheter that, in the judgment of the Investigator, could prevent adhering to radiation safety instructions.

Other protocol-defined Inclusion/Exclusion criteria may apply.

Novartis is committed to sharing with qualified external researchers, access to patient-level data and supporting clinical documents from eligible studies. These requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to respect the privacy of patients who have participated in the trial in line with applicable laws and regulations.

This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com