PARP-inhibitor on Advanced Metastatic Breast Cancer in Germline PALB2 Mutations Carriers (PALB2-PARPi-01)

Inclusion Criteria:

• Adult patients over 18 years
• PALB2 germline heterozygous mutation carrier, wild type BRCA1&2 (breast cancer 1&2) affected with metastatic breast cancer in first metastatic treatment line or beyond
• Histologically or cytologically confirmed breast cancer with evidence of metastatic disease.
• Triple Negative breast cancer; Patients affected with triple negative cancers should have received anthracyclines and taxanes in neo/adjuvant therapy.
• Or patients with Hormonal receptor positive (HR+)/ Human epidermal growth factor receptor 2 negative (HER2-) breast cancer, with treatment failure after a second line of therapy; Estrogen Receptor/ProgesteroneReceptor breast cancer positive patients must have received and progressed on currently recommended therapies in this indication (endocrine therapy, CDK4/6 inhibitors (adjuvant or metastatic)), or have a disease form that the treating physician believes to be inappropriate for recommended therapies in this indication.
• Prior therapy with an anthracycline and a taxane in an adjuvant setting.
• Prior platinum allowed as long as no breast cancer progression occurred on treatment or if given in adjuvant/neoadjuvant setting, at least 12 months elapsed from last dose to study entry.
• Eastern Cooperative Oncology Group (ECOG) performance status 0-2.
• Adequate bone marrow, kidney and liver function.
• Patients without visceral crisis

Exclusion Criteria:

• Patients with HER2 positive disease.
• Untreated and/or uncontrolled brain metastases.
• Patients in visceral crisis requiring chemotherapy
• Cytopenia, defined with the following thresholds: (i) Neutrophil count < 1500/mm3; Platelet count< 100 000/mm3; Hemoglobin <9g/dL
• Prior malignancy unless curatively treated and disease-free for > 5 years prior to study entry. Prior adequately treated non-melanoma skin cancer, in situ cancer of the cervix, ductal carcinoma in situ (DCIS) or stage I grade 1 endometrial cancer allowed.
• Known HIV (Human Immunodeficiency Virus) infection.
• Pregnant or breast-feeding women.
• Lack of affiliation to a social security benefit plan (as a beneficiary or assignee)