Lutetium (177Lu) dotatate Peptide: Structure, Research & Science Guide

By The Peptides Codex Editorial TeamReviewed September 8, 2026

Page data last changed: 2026-10-05. Registry refreshes and identity assessments are separate from scientific content review.

Reference backbone length

8 positions

Class

Radiolabelled somatostatin-analogue peptide (peptide receptor radionuclide therapy)

Function

A somatostatin-receptor-binding peptide that carries the beta-emitting isotope lutetium-177 into neuroendocrine tumour cells

Context

Approved (FDA, 2018) for somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours — the first peptide receptor radionuclide therapy approved in the US

A peptide as a delivery vehicle: octreotate finds somatostatin receptors on neuroendocrine tumours and the lutetium-177 it carries irradiates them from inside.

Also known as: 177Lu-DOTATATE · 177Lu-DOTA-Tyr3-octreotate · lutetium oxodotreotide · Lutathera (brand)

Part of the Foundational & therapeutic peptides cluster

Overview

Lutetium (177Lu) dotatate, marketed as Lutathera, is a radiolabelled somatostatin analogue: the peptide octreotate, linked through the chelator DOTA to the beta-emitting radioisotope lutetium-177, binds tightly to somatostatin receptors on neuroendocrine tumour cells and delivers radiation to them. The FDA approved it in 2018, based on the phase 3 NETTER-1 trial, for somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours — the first peptide receptor radionuclide therapy approved in the United States.

Source & context

Biological / chemical source: Octreotate, an octreotide-derived somatostatin analogue, chelated through DOTA to lutetium-177

Primary research or clinical context: Approved (FDA, 2018) for somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours — the first peptide receptor radionuclide therapy approved in the US

What lutetium dotatate is

Lutetium (177Lu) dotatate is a radiopharmaceutical with three parts: a peptide, a chelator and a radioisotope. The peptide is octreotate, a somatostatin analogue derived from octreotide with a tyrosine at position 3; the chelator DOTA holds the metal; and the metal is lutetium-177, a beta emitter. The whole construct is described as a molecular targeted therapy linking a beta-emitting radioisotope to dotatate, which binds tightly to somatostatin receptors on neuroendocrine tumour cells (Salner et al., Advances in Radiation Oncology 2021). It is marketed as Lutathera and recorded in PubChem as compound 76966897, CAS 437608-50-9.

Mechanism: the peptide as a homing device

Neuroendocrine tumours overexpress somatostatin receptors, the same receptors that octreotide and lanreotide act on to control hormone secretion. Dotatate exploits that overexpression: after intravenous infusion the peptide binds the receptors, the complex is internalised, and the lutetium-177 decays inside or immediately beside the tumour cell, delivering beta radiation over a range of a few millimetres. The approach is called peptide receptor radionuclide therapy (PRRT), and lutetium dotatate was the first PRRT approved by the US Food and Drug Administration (Salner et al. 2021).

Approval and evidence

The FDA approved lutetium Lu 177 dotatate in early 2018 for patients with somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours, based on the phase 3 NETTER-1 trial (Cancer Discovery 2018; Choy, P&T 2018). Well-designed European studies had shown dramatic effectiveness in improving progression-free survival in these tumours, which are progressive and generally metastatic (Salner et al. 2021). The indication is drug-label specific; the LactMed database notes that manufacturers recommend discontinuing breastfeeding during therapy and for 2.5 months after the last dose because of radioactivity in milk (LactMed 2025).

Administration and adverse effects

All patients currently receive 7,400 MBq (200 mCi) per cycle, and the drug is predominantly excreted by the kidneys (Taylor et al., Hemodialysis International 2024). Reported adverse effects include potential toxicity to renal, hepatic and haematological tissues and a risk of second malignancy; in one centre's first 12 patients, tumour flare reactions — worsening symptoms from bone or soft-tissue metastases — occurred in 5 (Salner et al. 2021). Dosing in haemodialysis has no guideline; one group reduced the standard activity by 33% for a first cycle and measured radiation exposure to staff (Taylor et al. 2024).

Key facts from the cited literature
Item	Detail	Source
Standard activity per cycle	7,400 MBq (200 mCi)	Taylor et al. 2024
Elimination	Predominantly renal	Taylor et al. 2024
Reported toxicities	Renal, hepatic, haematological; second malignancy risk; tumour flare	Salner et al. 2021
Breastfeeding	Discontinue during therapy and for 2.5 months after	LactMed 2025

Beyond the approved indication

Because somatostatin receptors occur on other tumours, lutetium dotatate is being studied more widely. A case report describes its use in a recurrent anaplastic meningioma that had progressed through surgery, radiation, everolimus with octreotide and other agents, after an indium-111 octreotide scan confirmed somatostatin receptors in the tumour (Zahid et al., Mayo Clinic Proceedings: Innovations, Quality & Outcomes 2021), and dosimetry methods for SSTR-targeted PRRT in refractory meningioma are under development (Boursier et al., European Radiology 2023). ClinicalTrials.gov lists 100 registered studies as of September 2026, including combinations with sunitinib (NCT05687123), olaparib (NCT04086485) and capecitabine–temozolomide (NCT05247905), retreatment strategies (NCT05773274) and inoperable pheochromocytoma and paraganglioma (NCT03206060).

Relation to other profiles

The peptide component descends from octreotide, profiled on this site, and is closely related to edotreotide, the DOTA-conjugated analogue used with gallium-68 for PET imaging of the same tumours — the diagnostic half of the theranostic pair. Lutetium vipivotide tetraxetan (Pluvicto) applies the same radioligand logic to prostate cancer with a PSMA-targeting peptidomimetic. All are hospital-administered approved medicines; none is a research peptide. This profile is educational and is not medical advice.

Sequence of the selected reference form

Sequence backbone for the reference form: Lutetium(177Lu) dotatate radiolabeled complex. Termini, stereochemistry and modifications are described below.

FCYWKTCT

Analyze sequences in the playground →

Structure & chemistry

Molecular identity & reference confidence

Source-supported reference

Select the Lutathera drug-substance complex with DOTA-bound lutetium-177, D-Phe1/D-Trp4 and Cys2-Cys7 disulfide. The label reports1609.6 Da; PubChem rounds its computed value to1609.5. This is an isotope-specific reference mass. Unmetallated DOTATATE, stable-lutetium complexes and other radiometals are different forms; average_mass_da remains null.

Molecular form: Lutetium(177Lu) dotatate radiolabeled complex
Species: Synthetic radiolabeled somatostatin analogue; species is not applicable
Termini (N / C): D-Phe1 amino group acylated by DOTA chelator containing lutetium-177 / L-Thr8 free carboxyl group

Reference mass (isotope-specific) · Molecular identity assessment: 2026-10-05

Reference policy updated: 2026-10-05

Current DailyMed Lutathera official label, Section11 · 2026-10-05
PubChem PUG chemical graph properties, CID76966897 · 2026-10-05
NIH NCATS/FDA GSRS exact full definition, UNII AE221IM3BB · 2026-10-05

Full sequence with modifications

[177Lu-DOTA]-D-Phe-L-Cys-L-Tyr-D-Trp-L-Lys-L-Thr-L-Cys-L-Thr-OH; Cys2-Cys7 disulfide

Molecular formula: C65H87[177Lu]N14O19S2
Reference mass (isotope-specific): ≈ 1,609.6
Receptors: Somatostatin receptors (predominantly subtype 2) overexpressed on neuroendocrine tumour cells
Backbone: Lutetium(177Lu) dotatate radiolabeled complex
C-terminus: L-Thr8 free carboxyl group
Status: Approved: FDA (2018) for SSTR-positive gastroenteropancreatic neuroendocrine tumours

Identifiers

PubChem CID: 76966897
CAS RN: 437608-50-9
UNII: AE221IM3BB

Chemistry values: curated profile, PubChem.

Clinical development snapshot

ClinicalTrials.gov lists 84 registered studies with “Lutetium dotatate” as an intervention (snapshot 2026-10-01). A registry footprint is not evidence of efficacy or approval.

Registered studies

Highest phase reached

Phase 4

Active in latest 100

Most recent update

2026-10-01

Most recently updated studies
NCT	Title	Phase	Status	Updated
NCT05773274	Comparing Retreatment of 177Lu-DOTATATE PRRT Versus the Usual Treatment in Patients With Metastatic Unresectab	Phase 2	recruiting	2026-10-01
NCT02743741	Lu-DOTATATE Treatment in Patients With 68Ga-DOTATATE Somatostatin Receptor Positive Neuroendocrine Tumors	Not applicable	completed	2026-09-29
NCT03971461	Phase II Study of 177Lu-DOTATATE Radionuclide in Adults With Progressive or High-risk Meningioma	Phase 2	active not recruiting	2026-09-29
NCT04086485	Lu-177-DOTATATE (Lutathera) in Combination With Olaparib in Inoperable Gastroenteropancreatico Neuroendocrine	Phase 2	recruiting	2026-09-28
NCT05583708	Phase II Study of Peptide Receptor Radionuclide Therapy in Combination With Immunotherapy for Patients With Me	Phase 2	recruiting	2026-09-25
NCT05109728	A Dose Finding Study of [177Lu]Lu-DOTA-TATE in Newly Diagnosed Glioblastoma in Combination With Standard of Ca	Phase 1	active not recruiting	2026-09-22

See all on ClinicalTrials.gov →

Concentration math

Lutetium (177Lu) dotatate — reconstitution calculator

Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.

Reference form: Lutetium(177Lu) dotatate radiolabeled complexReference mass (isotope-specific): 1,609.6 Da

Peptide in vial (mg)

Diluent added (mL)

Syringe graduation

Solution concentration

5 mg/mL5,000 mcg/mL

Amount to measure (optional)

mcg

Enter an amount to see the volume it corresponds to.

Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.

Open the Lutetium (177Lu) dotatate calculator on its own page →

Change log

Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.

2026-09-08IdentifiersCross-linked to PubChem CID 76966897.
2026-09-08TrialsClinicalTrials.gov snapshot added: 84 registered studies, highest phase 4.
2026-09-08EditorialProfile content reviewed and updated by the editorial team.

FAQ about Lutetium (177Lu) dotatate

What is Lutetium (177Lu) dotatate?+

What Canadian product status is recorded for Lutetium (177Lu) dotatate?+

Canadian product status for Lutetium (177Lu) dotatate has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.

What is the length of the selected reference form for Lutetium (177Lu) dotatate?+

The selected reference form (Lutetium(177Lu) dotatate radiolabeled complex) has 8 residues or residue-derived units in its backbone. Other forms in this family may have a different length.

What is lutetium dotatate?+

A radiopharmaceutical (Lutathera) in which the somatostatin-analogue peptide octreotate, chelated by DOTA, carries the beta-emitter lutetium-177 to somatostatin-receptor-positive neuroendocrine tumours.

How does Lutathera work?+

The peptide binds somatostatin receptors overexpressed on tumour cells; the attached lutetium-177 then irradiates those cells from within — peptide receptor radionuclide therapy.

Is lutetium dotatate approved?+

Yes. The FDA approved it in 2018 for somatostatin-receptor-positive gastroenteropancreatic neuroendocrine tumours, based on the NETTER-1 trial.

What are the side effects?+

The literature reports potential renal, hepatic and haematological toxicity, a risk of second malignancy, and tumour flare reactions shortly after treatment.

How is it related to octreotide?+

Octreotate is derived from octreotide; both bind somatostatin receptors. Octreotide controls hormone secretion, while dotatate delivers radiation.

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References & further reading

Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.

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