Evaluating 6 months of HER2-targeted therapy for early-stage breast cancer patients with a complete response to initial treatment

A Single-arm, Multicentre, Pragmatic Trial Evaluating 6-months of HER2-targeted Therapy in Patients With HER2 Positive Early-stage Breast Cancer That Achieve a Pathological Complete Response to Neoadjuvant Systemic Therapy (REaCT-HER TIME)

Phase 4 Interventional Ottawa Hospital Research Institute · NCT04928261

This study is testing if 6 months of HER2-targeted therapy can help early-stage breast cancer patients who have already responded well to initial treatment, while also reducing side effects and costs.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment50 (estimated)
Ages18 Years and up
SexAll
SponsorOttawa Hospital Research Institute Academic / other
Drugs / interventionschemotherapy, trastuzumab
Locations1 site (Ottawa, Ontario)
Trial IDNCT04928261 on ClinicalTrials.gov

What this trial studies

This trial investigates the effectiveness of administering 6 months of HER2-targeted therapy using trastuzumab for patients with early-stage, HER2-positive breast cancer who have achieved a pathological complete response (pCR) after receiving neoadjuvant systemic chemotherapy. The goal is to determine if a shorter duration of treatment can maintain positive outcomes while reducing the risk of cardiotoxicity and treatment costs. This multicenter, single-arm trial aims to provide insights into treatment de-escalation for patients who have shown excellent outcomes with initial therapy. Participants will be monitored for their response to the reduced treatment regimen.

Who should consider this trial

Good fit: Ideal candidates are patients with early-stage, HER2-positive breast cancer who have achieved a pathological complete response after neoadjuvant therapy.

Not a fit: Patients with residual invasive disease or those who have metastatic breast cancer will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could reduce treatment duration and associated side effects for patients with early-stage HER2-positive breast cancer.

How similar studies have performed: Other studies have shown promising results with treatment de-escalation in similar patient populations, indicating potential for success in this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Early-stage (I-III, i.e. non-metastatic) as per AJCC 8th edition, ER/PR positive or negative, HER2-positive as per 2018 American Society of Clinical Oncology/College of American Pathologists human epidermal growth factor receptor 2 (HER2) testing in breast cancer guidelines.
* Treated with neoadjuvant chemotherapy and HER2 targeted therapy preoperatively with a pathological complete response (pCR) defined as the absence of residual invasive cancer on hematoxylin and eosin evaluation of the complete resected breast specimen and all sampled regional lymph nodes following completion of neoadjuvant systemic therapy at surgery. Must have received less than 6 months of HER2 targeted therapy
* Able to provide verbal consent and complete questionnaires in English or French

Exclusion Criteria:

* Residual invasive disease following neoadjuvant therapy, or metastatic disease
* Contraindication to further HER2-targeted therapy following completion of neoadjuvant treatment
* Any psychological, familial, sociological or geographical condition potentially hampering compliance with the trial protocol

Where this trial is running

Ottawa, Ontario

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Breast CancerCardiac toxicitiesHer2 PositivePathological complete response
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.