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Observational study of HER2-low unresectable and metastatic breast cancer in Russia

A Multicenter Observational Retrospective Study of Therapeutic Approaches and Clinical Outcomes in Real Clinical Practice in Russian Patients With Human Epidermal Growth Factor Receptor 2 (HER2)-Low Unresectable and/or Metastatic Breast Cancer

Observational AstraZeneca · NCT05913440

This study looks at around 3,150 adults in Russia with advanced breast cancer to see how their HER2-low status affects their treatment and outcomes.

Quick facts

Study typeObservational
Enrollment1500 (estimated)
Ages18 Years and up
SexAll
SponsorAstraZeneca Industry-sponsored
Drugs / interventionstrastuzumab
Locations67 sites (Arkhangelsk and 66 other locations)
Trial IDNCT05913440 on ClinicalTrials.gov

What this trial studies

This observational study aims to enroll approximately 3,150 adult patients with HER2-negative unresectable or metastatic breast cancer in Russia. The goal is to confirm HER2 low status in about 2,000 patients through the reassessment of archival tumor samples. Participants must have a documented hormonal status and provide consent for data and sample usage. The study focuses on understanding the characteristics and outcomes of this specific patient population.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with confirmed unresectable or metastatic HER2-negative breast cancer diagnosed between July 1, 2021, and July 1, 2022.

Not a fit: Patients with a previous HER2 positive status or other malignancies may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance the understanding of HER2-low breast cancer and inform future treatment strategies.

How similar studies have performed: While this study focuses on a specific patient population, similar observational studies have shown promise in understanding breast cancer subtypes.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

* Patients with confirmed diagnosis of unresectable and/or metastatic BC established between the 1st July 2021 and the 1st July 2022.
* Patients have HER2-negative status (IHC0, IHC1+, IHC2+/ISH-) obtained in the local laboratory.

  -. Patients have an adequate archival tumor sample and slides suitable for reassessment HER2 status\* by the reference laboratory.
* Patients have documented hormonal status (ER, PR) IHC score.
* Age ≥ 18 years at the time of inclusion.
* Patients provided written consent allowing for data and samples to be used in the future and this study would be covered by the consent for future use in accordance with ICH GCP, GPP (Good Pharmacoepidemiology Practices) and local law prior to inclusion in the study. If the patient is deceased, a waiver may be accepted

Exclusion Criteria:

* Patients with previous HER2 positive status in the anamnesis at the diagnosis or after the diagnosis of breast cancer.
* Presence of other malignancies within period since diagnosis until the timepoint of data collection.
* Patients receiving trastuzumab deruxtecan currently or received in anamnesis.
* The participation in any randomised controlled trial within period since diagnosis until end of study.

Where this trial is running

Arkhangelsk and 66 other locations

+17 more sites — see ClinicalTrials.gov for the full list.

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.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Breast Cancer
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.