The main inclusion criteria include but are not limited to the following:
- Has locally recurrent unresectable or metastatic TNBC that cannot be treated with curative intent
- Has not received systemic treatment for locally recurrent unresectable or metastatic breast cancer
- Participants previously treated for early-stage breast cancer must have completed all prior therapy for early-stage breast cancer with curative intent at least 6 months before the first disease recurrence
- Is a candidate for treatment with pembrolizumab and one of the TPC options: paclitaxel or nab-paclitaxel or gemcitabine + carboplatin
- Participants who have AEs due to previous anticancer therapies must have recovered to ≤Grade 1 or baseline with the exception of alopecia or vitiligo. Participants with endocrine-related AEs who are adequately treated with hormone replacement are eligible
- Participants who are hepatitis B surface antigen (HBsAg) positive are eligible if they have received hepatitis B virus (HBV) antiviral therapy for at least 4 weeks, and have undetectable HBV viral load
- Participants with history of hepatitis C virus (HCV) infection are eligible if HCV viral load is undetectable
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
- Has breast cancer amenable to treatment with curative intent
- Has TNBC with evaluable tumor programmed death ligand 1 (PD-L1) expression at combined positive score (CPS) ≥10
- Has received prior systemic therapy for treatment of locally recurrent unresectable or metastatic breast cancer
- Has Grade ≥2 peripheral neuropathy
- Has history of documented severe dry eye syndrome, severe Meibomian gland disease and/or blepharitis, or severe corneal disease that prevents/delays corneal healing
- Has active inflammatory bowel disease requiring immunosuppressive medication or previous history of inflammatory bowel disease
- Has uncontrolled, significant cardiovascular disease or cerebrovascular disease
- Has skin only metastatic disease
- Has advanced/metastatic, symptomatic visceral spread at risk of rapidly evolving into life-threatening complications
- Human immunodeficiency virus (HIV)-infected participants with a history of Kaposi’s sarcoma and/or Multicentric Castleman’s Disease
- Has known additional malignancy that is progressing or has required active treatment within the past 5 years
- Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis. Participants with previously treated brain metastases may participate provided they are radiologically stable
- Active autoimmune disease that has required systemic treatment in the past 2 years. Replacement therapy (eg, thyroxine, insulin, or physiologic corticosteroid) is allowed
- History of (noninfectious) pneumonitis/interstitial lung disease that required steroids or has current pneumonitis/interstitial lung disease
- Concurrent active Hepatitis B (defined as HBsAg positive and/or detectable HBV deoxyribonucleic acid (DNA)) and Hepatitis C virus (HCV) (defined as anti-HCV antibody (Ab) positive and detectable HCV ribonucleic acid (RNA)) infection
- History of stem cell/solid organ transplant
- Has not adequately recovered from major surgery or has ongoing surgical complications