Study of Neoadjuvant Olaparib Monotherapy and Olaparib and Durvalumab Combination in HER2 Negative BRCAm Breast Cancer

Inclusion Criteria:

Males or Females ≥18 years
Minimum body weight of 30 kg
Capable of giving signed informed consent.
Male and Female participants of childbearing potential must use effective methods of contraception

Histologically confirmed, newly diagnosed, primary, operable, nonmetastatic invasive breast cancer with the following characteristics:

--ER-negative or ER-low defined as IHC nuclear staining ≤10%

HER2-negative (not eligible for anti-HER2 therapy) defined as:

IHC 0, 1+ without in situ hybridization OR
In situ hybridization non-amplified with ratio less than 2.0 OR
In situ hybridization average HER2 copy number < 6 signals/cells

Clinical TNM staging (per AJCC 8th Edition) as follows:

T1b (>5 mm but ≤10 mm), N0, no known metastases (M0 or MX); OR
T1c (>10 mm but ≤20 mm), N0, no known metastases (M0 or MX); OR
T1 (>1 mm but ≤20 mm), N1, no known metastases (M0 or MX); OR
T2 (>20 mm but ≤50 mm), N0, no known metastases (M0 or MX).).
Documented deleterious or suspected deleterious mutation in BRCA1 or BRCA2 from local BRCA testing using either a germline or tumour test.
Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
Participants must have adequate organ and bone marrow function
Participant must be willing to undergo a baseline research biopsy prior to start of study treatment.
Participant must be willing to have any leftover tumour tissue/FFPE from the diagnostic biopsy submitted for research purposes, if available.

Exclusion Criteria:

Any evidence of other diseases (such as severe or uncontrolled systemic diseases or active, uncontrolled infections, including but not limited to, uncontrolled ventricular arrhythmia, uncontrolled hypertension, recent [within 3 months] myocardial infarction, uncontrolled major seizure disorder, renal transplant, active bleeding diseases, unstable spinal cord compression, superior vena cava syndrome, extensive interstitial bilateral lung disease on High Resolution Computed Tomography scan
Refractory nausea and vomiting, chronic gastrointestinal disease likely to interfere with absorption of the study medication, inability to swallow the formulated product
History of another primary malignancy except for malignancy treated with curative intent with no known active disease for ≥5 years before the first dose of study intervention and of low potential risk for recurrence
Participants with MDS or AML
For higher risk (Cohort B) participants only: Active or prior documented autoimmune or inflammatory disorders (including inflammatory bowel disease [eg, colitis or Crohn's disease], diverticulitis [with the exception of diverticulosis], systemic lupus erythematosus, sarcoidosis, granulomatosis with polyangiitis, Graves' disease, rheumatoid arthritis, hypophysitis, uveitis, etc), autoimmune pneumonitis, and autoimmune myocarditis
Known active hepatitis infection, positive hepatitis C antibody, hepatitis B virus surface antigen or hepatitis B virus core antibody
Known to have tested positive for human immunodeficiency virus unless currently on effective anti-retroviral therapy with an undetectable viral load within 6 months
History of arrhythmia (multifocal premature ventricular contractions, bigeminy, trigeminy, ventricular tachycardia), which is symptomatic or requires treatment (Common Terminology Criteria for Adverse Events [CTCAE] Grade 3), symptomatic or uncontrolled atrial fibrillation despite treatment, or asymptomatic sustained ventricular tachycardia
Participant must not have had any prior treatment for the current breast cancer, including surgery, chemotherapy, hormonal therapy, radiation, or experimental therapy
For higher risk (Cohort B) participants only: Prior exposure to anti-PD1, anti-PD-L1, or anti-CTLA4 agents (ICIs); OR an agent directed to other co-inhibitory or co-stimulatory T-cell receptors
Any concurrent anticancer treatment
Major surgical procedure (excluding placement of vascular access, local surgery of isolated lesions, or diagnostic staging) within 2 weeks of the first dose of study intervention
For higher risk (Cohort B) participants only: Current or prior use of immunosuppressive medication within 14 days before the first dose of durvalumab.

Concomitant use of:

Known strong cytochrome P450 (CYP3A) inhibitors or moderate CYP3A inhibitors within 2 weeks prior to first dose of study intervention
Known strong CYP3A inducers or moderate CYP3A inducers .The required washout period prior to starting study therapy is 5 weeks for enzalutamide or phenobarbital and 3 weeks for other agents