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).
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
- Conditions the study is for
- Breast Cancer, Locally Advanced Breast Cancer (LABC)
- 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
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 group | Role | What they receive |
|---|---|---|
| Locally Advanced Breast Cancer Patients Cohort | Adult 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.
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)
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)
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)
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
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.
- First posted8 Apr 2026
- Study startJun 2026 (estimated)
- Primary completionJun 2027 (estimated)
- Study completionJun 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast CancerStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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)
Sponsor and investigators
- Lead sponsor
- Atlas University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Emine YILDIRIM, Atlas University
- Investigators
- Emine Yildirim, Principal investigator, Istanbul Atlas University Faculty of Medicine
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.
Study at a glance
From the registry record, last updated by the sponsor on 13 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT07516626
- Acronym / sponsor ID
- BC-PDO / ATLAS-BC-PDO-2026-01
- Keywords
- Neoadjuvant Chemotherapy, Chemotherapy Resistance, Patient-Derived Organoids, Drug Repurposing, Pathological Complete Response, Ex Vivo Drug Testing, Locally Advanced Breast Cancer
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Atlas UniversityUniversity, hospital or other
- Study start
- Jun 2026 (estimated)
- Primary completion
- Jun 2027 (estimated)
- Study completion
- Jun 2029 (estimated)
- First posted
- 8 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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.
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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Locally Advanced Breast Cancer Patients Cohort | – | –Adult 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. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- 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.
Key inclusion criteria (6 listed)
- 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
Key exclusion criteria (7 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Correlation Between PDO-Based Chemotherapy Response Metrics and Pathological Complete Response (pCR)
Time frame: At completion of neoadjuvant chemotherapy (approximately 6 months)
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.
4 secondary outcomes
Association Between PDO-Derived Drug Sensitivity Metrics and Clinical Chemotherapy Resistance
Time frame: At baseline (prior to initiation of neoadjuvant chemotherapy) and at completion of treatment (approximately 6 months)
Serum Apoptotic Biomarkers and Their Association With Treatment Response
Time frame: At baseline, during neoadjuvant chemotherapy, and at completion of treatment (approximately 6 months)
Evaluation of Drug Repurposing Strategies in PDO Models
Time frame: Within 6 months after sample collection
Development of Functional Predictive Models for Chemotherapy Response
Time frame: Within 12 months after completion of data collection
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Apr 2026.
- Individual participant dataSharing planned: 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Emine Yildirim principal investigator
Istanbul Atlas University Faculty of Medicine
1 site in 1 country: see every site and its status.
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.