Inclusion Criteria:

• Patients must have histologically confirmed adenocarcinoma of the breast at significant risk of distant recurrence based on at least one of the following criteria:

  • For axillary lymph node positive disease:

    • Involvement of at least one sentinel or axillary lymph node on routine histologic examination; patients with negative sentinel nodes and negative axillary nodes or involvement only demonstrated by immunohistochemistry are not eligible unless they meet one of the other eligibility criteria below

    • NOTE: consider intramammary nodes as equivalent to axillary nodes for the purposes of eligibility and stratification

  • For axillary lymph node negative disease:

    • Estrogen receptor (ER) negative tumor >= 1 cm

    • ER+ tumor >= 5 cm regardless of recurrence score

    • ER+ tumor >= 1 cm but < 5 cm with a recurrence score >= 11 (patients enrolled in the TAILORx trial are eligible)

    • NOTE: axillary dissection is strongly encouraged in patients with lymph node involvement identified on sentinel node biopsy

• Patients must have completed definitive breast surgery including total mastectomy and axillary dissection (modified radical mastectomy), total mastectomy and sentinel node biopsy, breast conservation surgery and axillary dissection or breast conservation surgery and sentinel node biopsy

  • NOTE: breast conservation surgery includes lumpectomy, partial mastectomy, and excisional biopsy

• Margins of breast conservation surgery or mastectomy must be histologically free of invasive breast cancer and ductal carcinoma in situ (DCIS); patients with resection margins positive for lobular carcinoma in situ (LCIS) are eligible

• Time from last surgery for breast cancer (breast conservation surgery, mastectomy, sentinel node biopsy, axillary dissection or re-excision of breast conservation surgery margins) to planned treatment start date must be > 28 days and =< 84 days

• Eastern Cooperative Oncology Group (ECOG) performance status 0-1

• Within =< 8 weeks prior to randomization: Absolute neutrophil count >= 1,000/mm^3

• Within =< 8 weeks prior to randomization: Platelet count >= 100,000/mm^3

• Within =< 8 weeks prior to randomization: Total bilirubin =< 1.5 mg/dL

• Within =< 8 weeks prior to randomization: Aspartate aminotransferase (AST) =< 2 times upper limit of normal(ULN)

• Within =< 8 weeks prior to randomization: Serum creatinine =< 1.5 mg/dL

• Within =< 8 weeks prior to randomization: Urine protein:creatinine ratio < 1.0 or 24-hour protein

• Within =< 8 weeks prior to randomization: Partial thromboplastin time (PTT) =< 1.5 times ULN

• Within =< 8 weeks prior to randomization: Left ventricle ejection fraction (LVEF) >= institutional limits of normal by multigated acquisition scan (MUGA) or echocardiogram (ECHO)

• Patients who have undergone breast conservation surgery must receive radiation; prior to randomization, the investigator must specify the planned radiation technique:

  • Whole breast radiation (WBRT) after chemotherapy

  • Accelerated partial breast radiation (APBI) after chemotherapy

  • Accelerated partial breast radiation (APBI) prior to chemotherapy

  • NOTE: if APBI was completed prior to study entry, day 1 of protocol therapy must be at least 4 weeks after the completion of APBI

• Post-mastectomy radiation therapy (RT) is required for all patients with a primary tumor of >= 5 cm or involvement of 4 or more lymph nodes; post-mastectomy RT may be administered at the investigator's discretion for all other mastectomy patients

• Patients with human epidermal growth factor receptor (HER)2 + (3+ by immunohistochemistry [IHC] or fluorescent in situ hybridization [FISH] ratio >= 2) breast cancer are not eligible

• Patients with synchronous bilateral breast cancer (diagnosed within one month) are eligible if the higher tumor, node, metastasis (TNM) stage tumor meets the eligibility criteria for this trial

• Patients must not have clinical evidence of inflammatory disease or fixed axillary nodes at diagnosis

• Patients must not have received prior cytotoxic chemotherapy or hormonal therapy for this breast cancer; prior treatment with an anthracycline, anthracenedione or taxane for any condition is not allowed

  • NOTE: prior use of tamoxifen for chemoprevention is allowed but must be discontinued at study entry; similarly, prior raloxifene use is allowed but must be discontinued at study entry

• Patients must not have had any major surgical procedure within 28 days of planned treatment start date

  • NOTE: non-operative biopsy or placement of a vascular access device is not considered a major surgery

• Patients may not have had placement of a vascular access device within 24 hours of planned day 1 of treatment

• Patients must not have clinically significant cardiovascular or cerebrovascular disease, including:

  • Any history of

    • Cerebrovascular disease including transient ischemic attack (TIA), stroke or subarachnoid hemorrhage

    • Ischemic bowel

  • Within the last 12 months

    • Myocardial infarction

    • Unstable angina

    • New York Heart Association (NYHA) class II or greater congestive heart failure

    • Grade II or greater peripheral vascular disease

    • Uncontrolled hypertension defined as systolic blood pressure (SBP) > 160 or diastolic blood pressure (DBP) > 90

    • Uncontrolled or clinically significant arrhythmia

    • NOTE: blood pressure must be obtained within =< 8 weeks prior to randomization

    • NOTE: patients with controlled atrial fibrillation are eligible

• Patients who require full-dose anticoagulation may enroll provided they meet the following criteria:

  • The patient must have an in-range international normalized ratio (INR) (usually between 2 and 3) on a stable dose of warfarin or be on stable dose of low molecular weight (LMW) heparin

  • The patient must not have active bleeding or pathological conditions that carry high risk of bleeding (e.g. varices)

  • NOTE: prophylactic use of anticoagulants to maintain patency of a vascular access device is permitted

• Patients must not have a bleeding diathesis, hereditary or acquired bleeding disorder or coagulopathy

• Patients must not have a non-healing wound or fracture; patients with an abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within 6 months prior to randomization are not eligible

• Patients must not have hypersensitivity to paclitaxel or drugs using the vehicle Cremophor, Chinese hamster ovary cell products or other recombinant human antibodies

• Women must not be pregnant or breast-feeding; all females of childbearing potential must have a blood or urine test within 7 days prior to randomization to rule out pregnancy

• Women of childbearing potential and sexually active males must use an accepted and effective method of contraception

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 08/12/2025. Questions regarding updates should be directed to the study team contact.