# TREAT ctDNA

Source: https://onco.cc/trials/treat-ctdna/  
OnCo record `treat-ctdna` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A European trial that gives the tablet elacestrant to women whose blood shows hormone-receptor-positive breast cancer returning before scans do, to see whether it delays spread.

## Summary

TREAT ctDNA (NCT05512364, EORTC) screens patients with ER-positive, HER2-negative breast cancer for ctDNA every six months; those who become ctDNA-positive by the Signatera assay (or another assay approved for diagnosis) without distant metastasis are randomised 1:1 to elacestrant or their current endocrine therapy (tamoxifen, letrozole, anastrozole or exemestane in the registry). Natera and the Menarini Group are collaborators. The primary endpoint is distant metastasis-free survival; primary completion is estimated for November 2032.

## Fields

- Kind: Trial
- Status: recruiting
- Last checked: 2026-11-04
- Also known as: EORTC-2129-BCG
- Registry id: NCT05512364
- Phase: 3
- Setting: ER-positive, HER2-negative stage IIB to III breast cancer with ctDNA relapse and no distant metastasis: elacestrant versus continuing the same endocrine therapy
- Sponsor: European Organisation for Research and Treatment of Cancer (EORTC)
- Enrolled: 220

## Sources

- ClinicalTrials.gov NCT05512364: https://clinicaltrials.gov/study/NCT05512364

## Connected records

- trials: [TRAK-ER](https://onco.cc/trials/trak-er/)
- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/)
- technologies: [MRD / molecular residual disease testing](https://onco.cc/technologies/mrd-testing/)
- targets: [Estrogen receptor (ERα)](https://onco.cc/targets/estrogen-receptor/)
- drugs: [Anastrozole](https://onco.cc/drugs/anastrozole/), [Elacestrant](https://onco.cc/drugs/elacestrant/), [Exemestane](https://onco.cc/drugs/exemestane/), [Letrozole (and other aromatase inhibitors)](https://onco.cc/drugs/letrozole/), [Signatera](https://onco.cc/drugs/signatera/), [Tamoxifen](https://onco.cc/drugs/tamoxifen/)
- companies: [Natera](https://onco.cc/companies/natera/)
- terms: [Circulating tumour DNA (ctDNA)](https://onco.cc/terms/ctdna/), [Minimal / molecular residual disease (MRD)](https://onco.cc/terms/mrd/), [Tumour-informed versus tumour-naive ctDNA assays](https://onco.cc/terms/tumour-informed-assay/)

---
JSON: https://onco.cc/api/v1/entities/treat-ctdna.json