Immune Induction Strategies to Improve Response to Immune Checkpoint Blockade in Triple Negative Breast Cancer (TNBC) Patients

Inclusion Criteria:

* Metastatic or incurable locally advanced triple negative breast cancer (ER \< 10%, HER2 IHC 0,1+ or 2+ with no amplification)
* Metastatic lesion accessible for histological biopsy
* 18 years or older
* Maximum of three lines of chemotherapy for metastatic disease and with evidence of progression of disease. Treatment with low-dose doxorubicin in the palliative setting is not allowed.
* WHO performance status of 0 or 1
* Measurable or evaluable disease according to RECIST 1.1
* Disease Free Interval (defined as time between first diagnosis or locoregional recurrence and first metastasis) longer than 1 year
* Subjects with brain metastases are eligible if these are not symptomatic and free of progression of at least 4 weeks
* A maximum dosage of 360 mg/m2 of anthracyclines and no previous anthracycline-related cardiac toxicity. In case of radiation in the cardiac area, hypertension, diabetes mellitus or hypercholesterolemia, the left ventricular ejection fraction must be 50% or higher.
* Adequate bone marrow, kidney and liver function

Exclusion Criteria:

* uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris
* known history of leptomeningeal disease localization
* history of having received other anticancer therapies within 2 weeks of start of the study drug
* history of immunodeficiency, autoimmune disease, conditions requiring immunosuppression (\>10 mgl daily prednisone equivalents) or chronic infections.
* prior treatment with immune checkpoint inhibitors.
* active other cancer
* history of uncontrolled serious medical or psychiatric illness
* current pregnancy or breastfeeding