Capecitabine in ER+/HER2-negative Breast Cancer

NCT07631052 | Recruiting Phase 2 DMC

• 1 other identifier: CATER MRD
• Study Type: interventional
• Target: 15
• Locations: 1 country
• Sites: 1

Brief Summary

This is a Phase 2 study for patients with resected Stage I-III HR+/HER2-negative breast cancer with detected molecular residual disease (MRD+) following standard neo/adjuvant and locoregional therapy delivered with curative intent. In this study participants will be treated with capecitabine. Capecitabine will be administered orally at a dose of 500 mg 3 times daily for up to 12 months, or until the time of clinical recurrence, discontinuation due to toxicity, or withdrawal of consent. This study will have two stages, stage 1 would enroll up to 8 participants to clear the Minimal Residual Disease (MRD) and Stage 2 will enroll up to 5 participants. The purpose of this study is to determine if this study population would have a better outcome from receiving capecitabine rather than having no change in treatment if MRD is detected.

Conditions

Breast Cancer Stage I; Breast Cancer Stage II; Breast Cancer Stage III; ER-positive, HER2-negative Breast Cancer

Outcome Measures

Primary Outcomes (1)

• Clearance rate of ctDNA at 16 weeks after the use of metronomic capecitabine measured using the Pathlight assay in patients with molecular residual disease (MRD). ctDNA clearance is defined as no detection of plasma ctDNA.

  Following Week 16 of treatment

Secondary Outcomes (3)

• Distant recurrence free survival (DRFS).

  Time of consent signed through to follow up (up to 5 years)

• Number and severity of treatment related adverse events as assessed by CTCAE v5.0.

  Time of consent signed through to 30 days last dose of study drug

• Measure ctDNA levels in MRD positive patients using the Pathlight assay after initiation of metronomic capecitabine.

  Time of consent signed through study completion, approximately 3 years

Other Outcomes (4)

• Number of patients with detectable residual disease and early treatment response using novel liquid biopsy.

  Through study completion, approximately 3 years.

• Proportion of patients with ctDNA clearance (defined as undetectable by the tumor-informed personalized ctDNA assay) and log-fold change in ctDNA quantification.

  Through study completion, approximately 3 years

• Frequency of tumor genomic alterations associated with subsequent development of ctDNA-detected molecular residual disease and treatment resistance during adjuvant surveillance and intervention in patients with primary ER+/HER2- breast cancer.

  Through study completion, approximately 3 years

Study Arms (1)

Capecitabine

EXPERIMENTAL

Capecitabine 500 mg

Drug: Capecitabine

Interventions

Capecitabine DRUG

Capecitabine 500 mg

Capecitabine

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female patients ≥ 18 years of age with histologically confirmed (by local assessment with ASCO/CAP criteria), resected ER-positive/HER2-negative stage I-III breast cancer
• Evidence of MRD (positive test by the Pathlight assay) despite standard adjuvant therapy
• No contraindications to capecitabine (including absence of DPYD variants that in the opinion of the investigator are a contraindication to metronomic capecitabine)
• No clinical or radiographic evidence of recurrent or metastatic disease
• Previous Therapy requirements: (i) Received at least 24 months of adjuvant endocrine therapy, including 6 months of an aromatase inhibitor and (i) Received at least 12 months of adjuvant CDK4/6i if indicated, unless not tolerated or declined
• ECOG performance status of 0-1.
• Patient must have adequate organ function as determined by the following:
• a. Renal function:
• Serum creatinine \< 1.5 x ULN (upper limit of normal range) or a calculated creatinine clearance of \> 50mL/min using the Cockcroft-Gault formula
• b. Bone marrow function (without hematopoietic growth factors or transfusion):
• Absolute neutrophil count (ANC) \> 1.0 x 109/L
• Hemoglobin \> 90 g/L or \> 9g/dL
• Platelets \> 75 x 109/L
• c. Liver function:
• Total bilirubin ≤ 1.5 × ULN and \< 35 uMol/L; OR total bilirubin \>1.5 × ULN with indirect bilirubin \< 1.5 × ULN.

You may not qualify if:

• Prior therapy with capecitabine.
• Previous or concurrent malignancy within 3 years of study entry, with the following exceptions: adequately treated basal or squamous cell skin cancer, superficial bladder cancer, prostate intraepithelial neoplasm, carcinoma in-situ of the cervix, or other non-invasive or indolent malignancy; other solid tumors treated curatively without evidence of recurrence for at least 3 years prior to study entry.
• Impaired cardiovascular function or clinically significant cardiovascular diseases, including any of the following:
• History of acute coronary syndromes (including myocardial infarction, unstable angina, coronary artery bypass grafting, coronary angioplasty, or stenting) \<6 months prior to screening,
• Symptomatic chronic heart failure (e.g., New York Heart Association Class ≥ 2), history or current evidence of clinically significant cardiac arrhythmia and/or conduction abnormality \<6 months prior to screening except atrial fibrillation and paroxysmal supraventricular tachycardia.
• Uncontrolled hypertension defined as persistent elevation of systolic blood pressure ≥ 160 mmHg or diastolic blood pressure ≥ 100mmHg, despite current therapy.
• Known positive serology for HIV (Human immunodeficiency virus) that is not currently controlled with antiretroviral therapy.
• Has a known history of or is positive for active hepatitis B or hepatitis C unless adequate viral suppression is achieved. Participants who have had definitive treatment for HCV are permitted if HCV RNA is undetectable at Screening Visit.
• Impaired gastrointestinal function or disease that may significantly alter the absorption of capecitabine.
• Medical, psychiatric, cognitive, or other conditions that may compromise the patient's ability to understand the patient information, give informed consent, comply with the study protocol, or complete the study.

Sponsors & Collaborators

• University Health Network, Toronto: lead

Study Sites (1)

UHN - Princess Margaret Cancer Centre

Toronto, Ontario, M5G 1Z5, Canada

RECRUITING

MeSH Terms

Conditions

Breast Neoplasms

Interventions

Capecitabine

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Intervention Hierarchy (Ancestors)

Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Fluorouracil; Uracil; Pyrimidinones; Deoxyribonucleosides; Nucleosides; Nucleic Acids, Nucleotides, and Nucleosides

Central Study Contacts

David Cescon, MD

CONTACT

416-946-2245; dave.cescon@uhn.ca

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 4, 2025
• First Posted: June 5, 2026
• Study Start (Estimated): June 30, 2026
• Primary Completion (Estimated): August 1, 2029
• Study Completion (Estimated): August 1, 2029
• Last Updated: June 11, 2026

Record last verified: 2026-06

Locations

CA (1)