Lutetium-177 DOTATATE

also known as: Lutathera, 177Lu-DOTATATE, Lutetium Lu 177 dotatate

A targeted radiotherapy peptide — a somatostatin analog armed with a radioactive warhead that delivers lethal radiation directly to neuroendocrine tumor cells expressing sst2 receptors.

An octreotide derivative (DOTA-Tyr3-octreotate) chelated with the beta-emitting radionuclide lutetium-177, providing peptide receptor radionuclide therapy (PRRT) by binding somatostatin receptor type 2 on neuroendocrine tumor cells and irradiating them from within.

Mechanism of action

The DOTATATE peptide binds sst2 with high affinity and is internalized via receptor-mediated endocytosis. Lutetium-177 emits beta particles (Emax 497 keV, range ~2 mm in tissue) that cause DNA double-strand breaks in the tumor cell and nearby cells (crossfire effect). The DOTA chelator stably binds ¹⁷⁷Lu, preventing systemic release. Kidneys and bone marrow are dose-limiting organs.

Primary uses

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs)
Midgut carcinoid tumors
Pheochromocytoma/paraganglioma (investigational)
sst2-positive tumor research

Typical dosing

7.4 GBq (200 mCi) every 8 weeks × 4 doses (intravenous infusion)

4 doses total. Amino acid infusion (Lys/Arg) co-administered for renal protection. Prior sst2 positivity confirmed by ⁶⁸Ga-DOTATATE PET scan.

Regulatory status

FDA-approved in 2018 (Lutathera, Novartis/AAA) for somatostatin receptor-positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Landmark NETTER-1 trial showed 79% reduction in risk of progression or death vs. octreotide LAR.

References

[clinical-trial] Strosberg J, et al. "Phase 3 trial of ¹⁷⁷Lu-Dotatate for midgut neuroendocrine tumors (NETTER-1)." N Engl J Med, 2017;376:125-135.
[fda-pi] Lutathera (lutetium Lu 177 dotatate) Prescribing Information. Novartis.

Related peptides

Octreotide

The first-generation somatostatin analog (FDA-approved as Sandostatin, 1988) — the pharmacological counterweight to growth-hormone excess. Used for acromegaly, carcinoid syndrome, and VIPoma; now available in injectable, LAR-depot, and oral (Mycapssa, 2020) formulations.

Lanreotide

The second-generation somatostatin analog (FDA-approved as Somatuline Depot, 2007 for acromegaly; 2014 for GEP-NETs; 2017 for carcinoid) — monthly deep-SC prefilled syringe. Functionally equivalent to octreotide LAR for most indications.

Pasireotide

The somatostatin analog for Cushing's disease — the only FDA-approved medical therapy targeting pituitary ACTH secretion, with uniquely broad somatostatin receptor affinity.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.