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Breast CancerBC-PDONCT07516626

Patient-Derived Organoids to Functionally Characterize Chemotherapy Resistance in Breast Cancer

An observational study of Breast Cancer and Locally Advanced Breast Cancer (LABC), run by Atlas University at 1 site in Turkey (Türkiye).

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This prospective observational study aims to functionally characterize chemotherapy resistance in patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy. Read more about this study

Who is it for?
Ages 18 years and older, women only
How many people
40 participants
Where
1 siteTurkey (Türkiye)
Study dates
Jun 2026to Jun 2029
Phase
Observational
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • Women only
  • No healthy volunteers
  • Adult, Older adult

Study population: Adult female patients diagnosed with locally advanced breast cancer and scheduled to receive neoadjuvant chemotherapy at a tertiary academic center. All participants will be recruited prospectively and followed during the course of standard clinical treatment.

Who may be able to join

  • Female patients aged 18 years or older
  • Histologically confirmed locally advanced breast cancer
  • Planned to receive neoadjuvant chemotherapy
  • Availability of tumor tissue obtained during routine diagnostic or therapeutic procedures
  • Availability of clinical and pathological treatment data
  • Ability to provide written informed consent

Who cannot join

  • Age under 18 years
  • Metastatic breast cancer
  • Prior systemic chemotherapy or targeted therapy for the current diagnosis
  • Presence of another active malignancy
  • Severe comorbid conditions that may interfere with study participation
  • Insufficient biological sample for organoid generation or analysis
  • Inability or unwillingness to provide informed consent

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Turkey (Türkiye)1 site
  • Istanbul Atlas University Faculty of Medicine

    Istanbul

Other trials in Turkey (Türkiye)

About this study

Official title: Functional Characterization of Neoadjuvant Chemotherapy Resistance in Breast Cancer Using Patient-Derived Organoid Models and Development of Drug Repurposing Strategies With Next-Generation Small Molecules

This prospective observational study aims to functionally characterize chemotherapy resistance in patients with locally advanced breast cancer undergoing neoadjuvant chemotherapy. Despite standard molecular classification, significant heterogeneity in treatment response exists, and the biological mechanisms underlying chemoresistance remain incompletely understood.

In this study, patient-derived organoid (PDO) models will be established from tumor tissues obtained during routine clinical care. These three-dimensional models preserve the biological characteristics of individual tumors and enable ex vivo functional assessment of drug response. Chemotherapy sensitivity and resistance will be evaluated using quantitative parameters including Half-Maximal Inhibitory Concentration (IC50) values, cell viability, and apoptotic response.

Read more

Functional data obtained from PDO models will be correlated with clinical and pathological treatment outcomes, particularly pathological complete response (pCR), to assess the predictive value of PDO-based assays. In addition, apoptotic biomarkers such as Caspase-3/7 will be measured in serum samples collected during routine clinical evaluation and analyzed in relation to treatment response.

Furthermore, selected Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved small molecules will be tested in PDO models to evaluate their potential to reverse chemotherapy resistance, supporting drug repurposing strategies. This study aims to establish a functional, patient-specific platform for assessing chemoresistance and to contribute to the development of personalized therapeutic approaches in breast cancer.

Read the detailed description

Breast cancer is one of the most common malignancies worldwide, and neoadjuvant chemotherapy (NACT) is a standard treatment approach in patients with locally advanced disease. Achieving pathological complete response (pCR) after NACT is strongly associated with improved long-term outcomes. However, significant inter-patient variability in treatment response is observed, even among patients with similar molecular subtypes, highlighting the need for functional approaches to better understand and predict chemotherapy resistance.

Current predictive models based on molecular and genomic profiling are limited in their ability to capture the dynamic and functional behavior of tumors. Patient-derived organoid (PDO) models have emerged as a promising platform that preserves tumor architecture, heterogeneity, and biological characteristics, enabling patient-specific functional drug testing in a controlled ex vivo environment.

In this prospective observational study, 40 adult female patients diagnosed with locally advanced breast cancer and scheduled to receive neoadjuvant chemotherapy will be enrolled. Tumor tissues obtained during routine diagnostic or therapeutic procedures will be used to establish PDO cultures. No additional invasive procedures will be performed for research purposes.

PDO models will be subjected to standardized drug response assays to evaluate chemotherapy sensitivity and resistance. Quantitative endpoints will include dose-response curves (Half-Maximal Inhibitory Concentration (IC50) values), cell viability assays, and apoptotic activity measurements, particularly Caspase-3/7 activation. These functional parameters will be integrated to define resistance phenotypes at the individual patient level.

Clinical and pathological response data, including pCR status, will be collected and correlated with PDO-derived functional results to assess the predictive performance of the PDO platform. In parallel, serum samples obtained during routine clinical care will be analyzed for apoptotic biomarkers, and their association with treatment response will be evaluated.

In addition, selected Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved small molecules, particularly those not currently used in breast cancer treatment, will be tested on PDO models to investigate their potential to overcome chemotherapy resistance. This approach aims to identify candidate agents for drug repurposing and to generate a functional drug sensitivity profile for each patient.

The ultimate goal of this study is to develop a reproducible and clinically relevant functional assay system that integrates ex vivo drug response data with clinical outcomes. This platform may contribute to improved prediction of treatment response, identification of resistance mechanisms, and development of personalized therapeutic strategies in breast cancer.

Keywords
Neoadjuvant Chemotherapy, Chemotherapy Resistance, Patient-Derived Organoids, Drug Repurposing, Pathological Complete Response, Ex Vivo Drug Testing, Locally Advanced Breast Cancer
Medical subject headings
Breast Neoplasms

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT07516626
Study groupRoleWhat they receive
Locally Advanced Breast Cancer Patients CohortAdult female patients diagnosed with locally advanced breast cancer and scheduled to receive standard neoadjuvant chemotherapy. Tumor tissue and blood samples obtained during routine clinical care will be used to generate patient-derived organoid models and to perform biomarker analyses. No experimental intervention will be applied to participants.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Correlation Between PDO-Based Chemotherapy Response Metrics and Pathological Complete Response (pCR)

    Assessment of the association between functional drug response parameters obtained from patient-derived organoid (PDO) models (including Half-Maximal Inhibitory Concentration (IC50) values, cell viability, and apoptotic response) and pathological complete response (pCR) following neoadjuvant chemotherapy.

    Measured: At completion of neoadjuvant chemotherapy (approximately 6 months)

Secondary outcomes (4)
  1. Association Between PDO-Derived Drug Sensitivity Metrics and Clinical Chemotherapy Resistance

    Evaluation of chemotherapy resistance phenotypes in patient-derived organoid (PDO) models using quantitative measures such as Half-Maximal Inhibitory Concentration (IC50), cell viability, and apoptotic response, and their relationship with clinical treatment outcomes.

    Measured: At baseline (prior to initiation of neoadjuvant chemotherapy) and at completion of treatment (approximately 6 months)

  2. Serum Apoptotic Biomarkers and Their Association With Treatment Response

    Analysis of serum apoptotic biomarkers, including Caspase-3/7 levels, and their correlation with pathological treatment response and chemotherapy resistance.

    Measured: At baseline, during neoadjuvant chemotherapy, and at completion of treatment (approximately 6 months)

  3. Evaluation of Drug Repurposing Strategies in PDO Models

    Assessment of the effects of selected Food and Drug Administration (FDA) and European Medicines Agency (EMA) approved small molecules on chemotherapy-resistant patient-derived organoid (PDO) models to evaluate their potential to reverse resistance.

    Measured: Within 6 months after sample collection

  4. Development of Functional Predictive Models for Chemotherapy Response

    Integration of PDO-derived functional data and clinical parameters to develop predictive models for treatment response in breast cancer patients.

    Measured: Within 12 months after completion of data collection

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Apr 2026
  2. Study startJun 2026 (estimated)
  3. Primary completionJun 2027 (estimated)
  4. Study completionJun 2029 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
40 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07516626
Sponsor's protocol ID
ATLAS-BC-PDO-2026-01
Acronym
BC-PDO
Status last verified
Mar 2026
First submitted
1 Apr 2026
Last updated
13 Apr 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: The plan for sharing individual participant data (IPD) has not yet been finalized. Data sharing will be determined based on institutional policies, ethical approvals, and funding conditions. De-identified data may be made available upon reasonable request after completion of the study and publication of primary results.

Questions about this trial

What is this clinical trial studying?

An observational study of Breast Cancer and Locally Advanced Breast Cancer (LABC), run by Atlas University at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 13 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Emine Yildirim, MD (+905056234825, emine.yildirim@atlas.edu.tr), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Correlation Between PDO-Based Chemotherapy Response Metrics and Pathological Complete Response (pCR) (time frame: At completion of neoadjuvant chemotherapy (approximately 6 months)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Apr 2026.

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