Inclusion Criteria:

          1. Anatomic stage I - III triple-negative breast cancer at diagnosis

          2. Estrogen receptors (ER) and Progesterone receptors (PR) status <10%

          3. Residual disease following at least 4 cycles of neoadjuvant chemotherapy. Patients who
             received other investigational immunotherapy or targeted therapy during the
             neoadjuvant phase of treatment are eligible.

          4. ≥ 18 years of age

          5. Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2

          6. All clinically significant toxic effects of prior cancer therapy resolved to Grade ≤ 1
             by the National Cancer Institute Common Terminology Criteria for Adverse Events,
             version 5.0 (NCI CTCAE, v 5.0), except alopecia and G2 neuropathy.

          7. No evidence of metastatic disease.

          8. A minimum 4-week wash out from previous chemotherapy treatment is required.

          9. Adequate hematologic function: Absolute neutrophil count (ANC) ≥ 1,500 cells/μL (≥
             1,500/mm3); Platelets ≥ 100,000 cells/μL (≥ 100,000/mm3)

         10. Adequate hepatic function: Bilirubin ≤ 1.5 times the specific institutional upper
             limit of normal (ULN). Exception: If Gilbert's syndrome; then ≤ 5 times ULN. Aspartate
             transaminase (AST) and alanine transaminase (ALT) each ≤ 2.5 x ULN

         11. Adequate renal function: Serum creatinine ≤ 1.5 x ULN; or calculated creatinine
             clearance > 50 mL/min using the Cockcroft Gault formula.

         12. Planned for 6 months or 8 cycles of adjuvant capecitabine.

         13. Women of childbearing potential (WOCBP) must have a negative pregnancy test.

         14. WOCBP must agree to use effective contraception during the study and for 3 months
             after the last dose.

         15. Male participants and their female partners of child bearing potential must be willing
             to use an appropriate method of contraception during the study and for 3 months after
             the last dose.

         16. Capable of giving signed informed consent, which includes compliance with requirements
             and restrictions listed in the informed consent form (ICF) and in the protocol

        Exclusion Criteria:

          1. Metastatic breast cancer

          2. Has not had definitive surgical resection

          3. Pregnant or breastfeeding

          4. Has not completed definitive adjuvant radiation if planned

          5. Known human immunodeficiency virus (HIV) positivity or active hepatitis B or C.

          6. Investigational agents within 4 weeks of study initiation

          7. Inability to swallow oral medications