• Willing and able to provide written informed consent.

• Ability to comply with the protocol.

• Female ≥ 18 years of age.

• Triple-negative disease, defined as tumour cells being:

‣ Negative for ER with \<10% of tumour cells positive for ER on IHC or IHC score (Allred) of ≤3.

⁃ Negative for PR with \<10% of tumour cells positive for PR on IHC or IHC score (Allred) of ≤3 or PR unknown, and

⁃ Negative for HER2 with 0, 1+ or 2+ intensity on IHC and no evidence of amplification on ISH.

• PDL1 negative, defined as 22C3 CPS\<10.

• Patients must have:

‣ at least one lesion, not previously irradiated, that can be measured accurately at baseline as ≥ 10mm in the longest diameter (except lymph nodes which must have short axis ≥ 15mm) with computed tomography (CT) or magnetic resonance imaging (MRI) performed within 28 days prior to randomisation which is suitable for accurate repeated measurements, or

⁃ lytic or mixed (lytic + sclerotic) bone lesions in the absence of measurable disease as defined above; patients with sclerotic/osteoblastic bone lesions only in the absence of measurable disease are not eligible. Patient that cannot be assessed by the CT or MRI should be excluded from the study.

• Representative formalin-fixed paraffin embedded (FFPE) breast tumour samples with an associated pathology report from the primary or recurrent cancer that are determined to be available and sufficient for central testing OR tumour accessible for biopsy.

• ECOG performance status 0-1.

• Life expectancy ≥12 weeks.

⁃ Adequate haematologic and end-organ function within 28 days prior to the first study treatment defined by the following:

∙ Absolute neutrophil count ≥ 1500 cells/μL (1.5 x 109/L) (without granulocyte) colony-stimulating factor support within 2 weeks prior to Cycle 1, Day 1).

‣ WBC \> 2500/μL (2.5 x 109/L).

‣ Platelet count ≥ 100,000/μL (100 x 109/L) (transfusion not permitted within 28 days of study medication).

‣ Haemoglobin ≥ 9.0 g/dL (90g/L) with no blood transfusions (packed red blood cells).

‣ Serum albumin ≥ 3g/dL.

‣ AST (SGOT) or ALT (SGPT) and ALP ≤ 2.5 times the institutional upper limit of normal (ULN), bilirubin ≤ 1.5 x ULN (patients with liver metastases who have AST or ALT ≤ 5 x the institutional ULN may be enrolled).

‣ aPTT ≤ 1.5 × the institutional ULN, INR \<1.5 and absence of evidence of impaired hepatic synthesis function. This applies only to patients who are not receiving therapeutic anticoagulation; patients receiving therapeutic anticoagulation should be on a stable dose.

‣ Serum Creatinine ≤ 1.5 x institutional ULN.

‣ Glomerular filtration rate ≥ 40mL/min as assessed by standard methodology at the investigating center (i.e., Cockcroft Gault, MDRD or CKD-EPI formulae, EDTA clearance or 24 h urine collection).

‣ No evidence of haematuria: +++ on microscopy or dipstick.

⁃ Patients of childbearing potential are eligible provided they have a negative serum or urine pregnancy test on Cycle 1, Day 1 (within 72 hours) of study treatment, preferably as close to the first dose as possible. Patients must agree to use adequate contraception, defined as those methods with a failure rate of \< 1 % per year beginning 14 days before the first dose of study drug and for 7 months after the last dose of study drug. Also, participants must not donate, or retrieve for their own use, ova at any time during this study and for at least 7 months after the last dose of treatment. Preservation of ova should be considered prior to randomisation or the first dose of study intervention.

⁃ Body Weight \> 30 kg.