Inclusion Criteria:

• Eligible participants will be adults (≥18 years old) who have a history of histologically confirmed diagnosis of TNBC (clinical stage II-III), except inflammatory breast cancer. Bilateral and/or multifocal primary tumors are allowed. For multifocal/multicentric disease, diagnosis needs to be confirmed for each focus. Participants have confirmed TNBC (as defined by the 8th edition of American Joint Committee on Cancer [AJCC] cancer staging manual and National Comprehensive Cancer Network [NCCN] guidelines), Eastern Cooperative Oncology Group (ECOG) Performance Status (PS) of ≤2, and plan to undergo breast-conserving surgical treatment of breast cancer with curative intent within 28 days of Screening.

Exclusion Criteria:

• Participants will not be eligible if they anticipate requiring the use of a drain after BCS, and/or have received neoadjuvant therapy, and/or are undergoing immediate reconstruction surgery with flaps involving transposition of a vascularized tissue flap from a remote donor site (oncoplastic closures are allowed), intraoperative radiation therapy (IORT) or brachytherapy requiring the placement of balloons or catheters during the lumpectomy procedure, and/or have a history of invasive malignancy (other than the disease under trial, ≤5 years prior to signing informed consent except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer), and/or have stage IV disease.