An interventional study of ctDNA-Guided Treatment Strategy in Breast Neoplasms, Carcinoma, Ductal, Breast and Receptors, Estrogen (for ER-positive Requirement), sponsored by Natera, Inc.. Recruiting at 50 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Natera, Inc. · Not applicable, Interventional, and Treatment
The purpose of this study is to evaluate the efficacy and safety of ctDNA-guided initiation of CDK4/6 inhibitor therapy using the Signatera™ Designed on Genome test (referred to as "Signatera Genome") in participants with intermediate-risk HR+/HER2- early-stage breast cancer. Based on ctDNA test results, participants will either start CDK4/6 inhibitor therapy in addition to hormone therapy or continue hormone therapy with ongoing ctDNA surveillance. This study will compare outcomes to historical controls from the NataLEE trial to determine whether ctDNA-guided timing maintains efficacy while reducing unnecessary treatment. Participants will be followed for up to 9 years with regular blood draws, hormone therapy, imaging as needed, and quality-of-life assessments.
Participants with intermediate-risk, early-stage HR+/HER2- breast cancer will be enrolled in a prospective, single-arm, multicenter phase II study. Circulating tumor DNA (ctDNA) surveillance will be performed using the Signater Genome assay, which is customized for each participant from archived tumor and matched normal DNA to detect up to 64 tumor-specific variants in plasma.
Participants who are ctDNA positive at baseline will start CDK4/6 inhibitor therapy along with hormone therapy. Those who are ctDNA negative will continue hormone therapy with ctDNA testing every three months. If ctDNA becomes positive during surveillance, participants will first undergo staging to rule out distant disease before beginning CDK4/6 inhibitor therapy in addition to hormone therapy.
All participants will be followed for up to nine years to assess cancer outcomes. Four-year outcomes will be compared to historical controls from the NataLEE trial to evaluate whether ctDNA-guided timing maintains efficacy while reducing unnecessary treatment.
86 studies on the registry are indexed under Carcinoma, Ductal, Breast; 7 are open to participants now.
This study's planned enrollment of 725 is above the median of 92 across 69 interventional studies indexed under Carcinoma, Ductal, Breast.
Browse Carcinoma, Ductal, Breast studies →Natera, Inc. is the lead sponsor of 36 studies on the registry; 11 are open to participants now.
Compared within Carcinoma, Ductal, Breast, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Breast Neoplasms. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Patient after surgical resection where tumor was removed completely (i.e., negative microscopic margins on final pathology) and have Anatomic Stage II that is eligible for adjuvant CDK4/6 inhibitors. The criteria to be eligible for adjuvant CDK4/6 inhibitors include N1, or N0 with T3 or T2 with either G3, or G2 with Ki67 greater or equal to 20% or high genomic risk score.
Notes:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adjuvant and neoadjuvant
Neoadjuvant treatment is given before the main treatment (usually surgery), often to shrink a tumour. Adjuvant treatment is given after it, to lower the chance of the cancer coming back.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HER2
HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.
In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Reproductive potential
Able to have children. For women this usually means from the first period until menopause, unless permanently unable to through surgery; for men, unless permanently sterile. Read who the line is about — participants, women, men, or their partners.
Criteria about it usually ask for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
All participants receive circulating tumor DNA (ctDNA) testing using Signatera Genome every 3 months to guide treatment decisions. Participants with positive ctDNA results initiate CDK4/6 inhibitor therapy (ribociclib or abemaciclib) in addition to standard endocrine therapy. Participants with negative ctDNA results continue endocrine therapy alone with ongoing ctDNA surveillance. All participants continue their assigned treatment pathway until disease progression, unacceptable toxicity, or study completion.
Device: ctDNA-Guided Treatment Strategy
Circulating tumor DNA testing using Signatera Genome assay is performed every 3 months for up to 4 years to guide timing of CDK4/6 inhibitor initiation. Participants with positive ctDNA results initiate CDK4/6 inhibitor therapy (ribociclib or abemaciclib) plus standard endocrine therapy for a minimum of 2 years. Participants with negative ctDNA results continue endocrine therapy alone with ongoing surveillance. CDK4/6 inhibitor selection and endocrine therapy regimen per the physician's choice following standard-of-care guidelines.
This study also gives Ribociclib, Abemaciclib. No intervention listed here names it: that was found by reading the record.
Invasive Disease-Free Survival
The primary objective of this study is to to evaluate disease free survival (iDFS) in patients with intermediate risk breast cancer receiving standard endocrine therapy with the addition of CDK4/6 inhibitor therapy upon positive ctDNA test results as compared to historical data of treated patients (NataLEE).
Time frame: From the date of surgery up to 9 years
Plan to share: No
Started May 2026 (actual). Primary completion is estimated for May 2032, 72 months after the start.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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Studies of the drug tested here: Ribociclib