What it is
Dotatate is an eight-amino-acid ring peptide with a metal cage attached. The NETSPOT label gives its sequence as D-Phe-Cys-Tyr-D-Trp-Lys-Thr-Cys-Thr, closed into a ring by a disulfide bond between the two cysteines, with the chelator DOTA — a molecular cage that grips a metal ion — bound to the first residue. Its full name, DOTA-0-Tyr3-octreotate, describes exactly that: DOTA at position 0, tyrosine at position 3, and "octreotate", the acid form of octreotide. Molecular weight 1,435.6 Da.
Set beside the octreotide label, the peptide differs in two places (our comparison): tyrosine in place of phenylalanine at position 3, and a plain threonine acid at the end where octreotide has threoninol. Both are copies of the body's somatostatin, shrunk from 14 residues to 8 and made resistant to digestion by the two mirror-image (D) amino acids.
How it works
Many neuroendocrine tumours carry somatostatin receptors. Dotatate binds them, with highest affinity for subtype 2 (SSTR2) according to the Lutathera label, is taken into the cell, and the metal in its cage decides what happens next:
| Product | Metal | Use | First US approval |
|---|---|---|---|
| NETSPOT (kit) | gallium-68 | PET scan to locate tumours | 2016-06-01 (NDA 208547) |
| Detectnet | copper-64 | PET scan to locate tumours | 2020-09-03 (NDA 213227) |
| Lutathera | lutetium-177 | Radiation treatment (PRRT) | 2018-01-26 (NDA 208700) |
The scan and the treatment use the same peptide, which is why a positive scan is how teams check that a tumour will take up the treatment. NETTER-1 required receptor uptake "on all lesions" at least equal to normal liver before anyone could enrol (label).
What the trials show
Treatment — NETTER-1 (NCT01578239) randomised 229 people with progressive, well-differentiated midgut tumours to Lutathera 7.4 GBq every 8 weeks for up to four doses plus octreotide 30 mg, or high-dose octreotide 60 mg alone. It was open-label, with progression read by a blinded committee:
| Measure | Lutathera + octreotide (116) | Octreotide 60 mg (113) |
|---|---|---|
| Progression or death | 27 (23%) | 78 (69%) |
| Median progression-free survival | not reached | 8.5 months |
| Hazard ratio | 0.21 (0.13–0.32) | — |
| Overall response | 13% | 4% |
| Final overall survival (66 months later) | no statistically significant difference |
The broader indication — tumours of the foregut, midgut and hindgut — rests on ERASMUS, a single-site Dutch expanded-access programme. The label notes that its Lutathera-specific protocol was written eight years after the study began, with no sample size or hypothesis plan; of 1,214 people treated, 360 formed the efficacy set and the response rate was 17%.
Imaging. NETSPOT's approval rests on three open-label single-centre studies. In Study A (97 adults), of 50 patients whose tumours were found by CT or MRI, the gallium scan was positive in 48 — including 13 whose older indium In 111 pentetreotide scan had been negative — and negative in 26 of 28 whose CT or MRI was negative. Detectnet's rests on two single-centre studies, Study 1 with 63 subjects (42 patients, 21 healthy volunteers) read by three blinded readers.
Safety
For the treatment, the Lutathera label's warnings are radiation exposure, myelosuppression, later myelodysplastic syndrome and leukaemia — MDS in 2.3% of NETTER-1 patients vs none on octreotide; in ERASMUS 2.0% MDS and 0.5% acute leukaemia, with median onset 29 and 55 months — kidney toxicity (eight ERASMUS patients, under 1%, developed renal failure 3–36 months later), liver toxicity, hypersensitivity, neuroendocrine hormonal crisis (flushing, diarrhoea, low blood pressure as a tumour releases its hormones), fetal harm and infertility. An amino-acid solution is given before, during and after each dose "to decrease the reabsorption" of the drug by the kidneys (label). The NETSPOT label's warnings are cumulative radiation exposure (close contact with infants and pregnant women restricted for the first 12 hours), hypersensitivity — mostly rash and itching — and image misinterpretation, because uptake also appears in other tumour types, in splenosis and as a normal variant such as the uncinate process of the pancreas.
Where it stands
- Approved in the US as NETSPOT (2016-06-01), Lutathera (2018-01-26; efficacy supplements 2020, 2022 and 2024-04-23; the indication now covers patients 12 and older) and Detectnet (2020-09-03) (Drugs@FDA, data 2026-10-16). Lutathera label effective 2026-01-15, NETSPOT 2026-07-06.
- Research record: PubMed indexes 3,061 records for dotatate (852 for the lutetium form), 22 tagged as randomised controlled trials; ClinicalTrials.gov lists 228 studies naming DOTATATE (2026-10-17).
Related reading
Dotatate's peptide is a near twin of octreotide and a cousin of lanreotide, both copies of the body's somatostatin. The same carry-a-radioactive-atom idea, built on a non-classic peptide, is vipivotide tetraxetan in Pluvicto.