This study is to evaluate the progression-free survival (PFS) of SHR-A1811 combined with SHR-1316 in the first-line treatment of PD-L1-positive locally recurrent unresectable or metastatic triple-negative breast cancer with Toripalimab combined with Nab-paclitaxel, as assessed by blinded independent central review (BICR).

Inclusion Criteria:

1. Age 18-75 years old (including both ends), female.
2. Pathologically confirmed locally recurrent unresectable or metastatic triple-negative breast cancer.
3. Expected survival ≥ 12 weeks.
4. Have adequate renal and hepatic function.
5. Patients voluntarily joined the study and signed the informed consent.

Exclusion Criteria:

1. Patients with active central nervous system (CNS) metastases who have not undergone surgery or radiotherapy.
2. Have other malignancies within the past 5 years.
3. Presence with uncontrollable third space effusion.
4. Have undergone other anti-tumor treatment within 4 weeks before the first dose.
5. A history of immunodeficiency.
6. Clinically significant cardiovascular diseases.
7. Known or suspected interstitial lung disease.
8. Known hereditary or acquired bleeding tendency.
9. Toxicities from prior anti-tumor therapy that have not recovered to ≤ Grade 1.
10. Known hypersensitivity to any of the study drugs or their excipients, or a history of allergy to humanized monoclonal antibody products.
11. Presence of other severe physical or mental disorders or clinically significant laboratory abnormalities.