Clinical trial Recruiting at 21 sites Interventional Ages 18 and up

Evaluating biomarkers for PARP inhibitor resistance in breast cancer patients with BRCA mutations

Official title: Prospective and Multicentric Study Evaluating DNA Double-strand Breaks (DSBs) REpair Factors (POLQ, Shieldin Complex and 53BP1) Expression as Biomarker of PARP Inhibitor Resistance in Patients With Deleterious Germline Mutation in BRCA 1/2 and HER2-negative, Metastatic or Locally Advanced Breast Cancer.

Run by Institut Claudius Regaud · NCT05378204 · Data updated 2026-11-12

This study is testing if certain DNA repair factors can help explain why some breast cancer patients with BRCA mutations don't respond to PARP inhibitors.

More Breast Cancer trials

Quick facts

Study typeInterventional
Ages18 Years and up
SexAll
Enrollment120 (estimated)
SponsorInstitut Claudius Regaud
Academic / other
Drugs / interventionschemotherapy, immunotherapy
Locations25 sites (Bordeaux and 24 other locations)
StatusRecruiting
StartedJune 23, 2022
Main results expectedJanuary 2027
Study endsJune 2027
Registry record updatedFebruary 20, 2026
Trial IDNCT05378204 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates include adults with HER2-negative, locally advanced or metastatic breast cancer and deleterious germline BRCA1/2 mutations who are eligible for PARP inhibitor therapy.

Probably not a fit

Patients with breast cancer who do not have BRCA mutations or those with HER2-positive tumors may not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This study aims to investigate the correlation between the expression of specific DNA repair factors (POLQ, Shieldin complex, and 53BP1) and resistance to PARP inhibitors in patients with HER2-negative, locally advanced or metastatic breast cancer who have deleterious germline BRCA1/2 mutations. It consists of two multicentric, non-randomized prospective studies: the main study involving 80 patients eligible for PARP inhibitor treatment and a sub-study involving 40 patients experiencing disease progression while on PARP inhibitors. Tumor biopsies and blood samples will be collected at various points to assess the relationship between biomarker expression and treatment outcomes.

Why it matters

Potential benefit: If successful, this study could help identify biomarkers that predict resistance to PARP inhibitors, potentially leading to more personalized and effective treatment strategies for breast cancer patients.

How similar studies have gone: Other studies have shown promise in identifying biomarkers related to PARP inhibitor resistance, making this approach both relevant and potentially impactful.

Who can join: the full rules

Show full inclusion / exclusion criteria
MAIN STUDY

INCLUSION CRITERIA:

1. Women (or men) aged ≥ 18 years with histologically proven breast cancer
2. Metastatic relapse or locally advanced breast cancer
3. No-HER2 overexpression or amplification
4. Triple-negative (defines as ER\<1%, PR\<1% and HER2-negative as per ASCO CAP guidelines) or hormone receptor positive (defines as ER and/or PR ≥ 1%) breast cancer
5. Patients with metastases that can be biopsied except bone metastases. At baseline, if patients already have an archived biopsy from a secondary or a primary site (if stage IV) of their current disease, this material can be used for the study, provided that, it was collected within 3 months prior enrollment and a frozen and a FFPE sample are both available for research
6. ECOG Performance Status ≤ 2
7. Patients must have measurable or evaluable disease according to RECIST v1.1
8. Patient with deleterious germline BRCA 1 and/or 2 mutation, eligible for PARP inhibitor therapy (olaparib or talazoparib), according each investigator
9. Any number of prior lines therapy are allowed
10. Current treatment with PARP inhibitor not yet started
11. Women should be post-menopaused or willing to accept the use of an effective contraceptive regimen during the treatment period by PARP inhibitor
12. Patient able to participate and willing to give informed consent prior performance of any study-related procedures and to comply with the study protocol
13. Patient affiliated to a Social Health Insurance in France

NON-INCLUSION CRITERIA:

1. Abnormal coagulation contraindicating biopsy
2. Bone metastases when this is the only site of biopsiable disease
3. Patients with all target in a previously irradiated region, except if clear progression has been observed prior to study in at least one of them
4. Patients with known additional malignancy that is progressing or requires active treatment. Exceptions include basal cell carcinoma of the skin or squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer
5. Patients with known untreated CNS metastases and/or carcinomatous meningitis
6. Patients with a known history of Human Immunodeficiency Virus (HIV)
7. Patients with known active Hepatitis B or C
8. Patients should not be on any other anti-cancer therapy (chemotherapy, endocrine therapy, immunotherapy, tailored therapy or alternative investigational therapy)
9. Patient pregnant, or breast-feeding
10. Any psychological, familial, geographic or social situation, according to the judgment of investigator, potentially preventing the provision of informed consent or compliance to study procedure
11. Patient who has forfeited his/her freedom by administrative or legal award or who is under legal protection (curatorship and guardianship, protection of justice)

SUB-STUDY

INCLUSION CRITERIA:

1. Women (or men) aged ≥ 18 years with histologically proven breast cancer
2. Metastatic relapse or locally advanced breast cancer
3. No-HER2 overexpression or amplification
4. Triple-negative (defines as ER\<1%, PR\<1% and HER2-negative as per ASCO CAP guidelines) or hormone receptor positive (defines as ER and or PR ≥ 1%) breast cancer
5. Patients with metastases that can be biopsied except bone metastases
6. ECOG Performance Status ≤ 2
7. Patients, with deleterious germline BRCA 1 and/or 2, in progression under PARPi alone (talazoparib or olaparib)
8. Patient able to participate and willing to give informed consent prior performance of any study-related procedures and to comply with the study protocol
9. Patient affiliated to a Social Health Insurance in France

NON-INCLUSION CRITERIA:

1. Abnormal coagulation contraindicating biopsy
2. Bone metastases when this is the only site of biopsiable disease
3. Patient pregnant, or breast-feeding
4. Patients with a known history of Human Immunodeficiency Virus (HIV)
5. Patients with known active Hepatitis B or C
6. Any psychological, familial, geographic or social situation, according to the judgment of investigator, potentially preventing the provision of informed consent or compliance to study procedure
7. Patients already participating in the main REPARP study
8. Patient who has forfeited his/her freedom by administrative or legal award or who is under legal protection (curatorship and guardianship, protection of justice)

Where it's running

  • Institut Bergonie
    Bordeaux, France
    Recruiting
  • Centre Francois Baclesse
    Caen, France
    Recruiting
  • Centre Jean Perrin
    Clermont-Ferrand, France
    Recruiting
  • Centre Hospitalier Départemental Vendée
    La Roche-sur-Yon, France
    Recruiting
  • Centre Oscar Lambret
    Lille, France
    Recruiting
  • CHU de LIMOGES
    Limoges, France
    Recruiting
Show 19 more locations
  • Centre Leon Berard
    Lyon, France
    Recruiting
  • Institut Paoli Calmettes
    Marseille, France
    Recruiting
  • Centre de Cancerologie Du Grand Montpellier
    Montpellier, France
    Recruiting
  • Institut Regional Du Cancer de Montpellier
    Montpellier, France
    Recruiting
  • CHU de Nimes
    Nîmes, France
    Recruiting
  • Hopital Pitie Salpetriere
    Paris, France
    Recruiting
  • Hopital Saint Louis
    Paris, France
    Recruiting
  • Hopital Tenon
    Paris, France
    Recruiting
  • Chu de Poitiers
    Poitiers, France
    Recruiting
  • Chu Saint Etienne
    Saint-Etienne, France
    Recruiting
  • INSTITUT DE CANCEROLOGIE DE L'OUEST St-Herblain
    Saint-Herblain, France
    Recruiting
  • Iuct-O
    Toulouse, France
    Recruiting
  • Chru de Tours
    Tours, France
    Recruiting
  • Institut de Cancerologie de Lorraine
    Vandœuvre-lès-Nancy, France
    Recruiting
  • Institut Gustave Roussy
    Villejuif, France
    Recruiting
  • Centre Georges Francois Leclerc
    Dijon, France
    Withdrawn
  • INSTITUT CURIE - Site de Paris
    Paris, France
    Withdrawn
  • CENTRE ARMORICAIN DE RADIOTHERAPIE, IMAGERIE MEDICALE ET ONCOLOGIE - Hôpital privé des Côtes d'Armor
    Plérin, France
    Not yet recruiting
  • Centre Eugene Marquis
    Rennes, France
    Withdrawn

Study contacts

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 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.