This multicenter, randomized, double-blind study will evaluate the safety and efficacy of PM8002 in combination with Nab-Paclitaxel compared with placebo combined with Nab-Paclitaxel as first-line treatment in inoperable locally advanced/metastatic triple-negative breast cancer(TNBC)

Inclusion Criteria:

• Ability to understand and willing to provide written informed consent and to comply with scheduled visits and study procedures;
• Female, aged 18 to 70 years (inclusive);
• Histologically confirmed unresectable locally advanced or metastatic breast cancer with negative status for ER, PR, and HER-2. Testing results for all three markers conducted within 24 months prior to the initiation of the study by a local facility accredited by clinical research center are acceptable. If deemed necessary by the investigator during screening, subjects may provide additional biopsy to confirm the latest pathological;
• Subjects who have not received prior systemic treatment（except endocrine therapy） for advanced breast cancer are eligible for the study. Subjects who have received Taxane-based chemotherapy during the neoadjuvant and/or adjuvant treatment phase are eligible, as long as the occurrence of relapse or metastasis is at least 12 months after the end of treatment;
• Performance status as assessed by the Eastern Cooperative Oncology Group (ECOG) is 0-1;
• Life expectancy of 12 weeks or more;
• According to RECIST 1.1, the subject has at least 1 measurable lesion as the targeted lesion (the only bone metastasis or the only central nervous system metastasis should not be considered as a measurable lesion. A measurable lesion located at the previously irradiated radiation field or other local treatment area should not be selected as targeted lesion, unless the lesion shows unequivocal radiographic progression).

Exclusion Criteria:

• Previous treatment with immune checkpoint agonists (such as CD137 agonists) or immune checkpoint inhibitors (such as CTLA-4, PD-1, PD-L1, LAG3 monoclonal antibody, etc.) or anti-vascular endothelial growth factor (VEGF) target drugs;
• Has uncontrolled or symptomatic brain or spine cord metastases;
• Those who have had other active malignant tumors within 5 years prior to the study treatment, except for those that can be treated locally and have been cured ;
• Poorly controlled hypertension (systolic blood pressure ≥ 140 mmHg and/or diastolic blood pressure ≥ 90 mmHg);
• With a history of hypertensive crisis or hypertensive encephalopathy;
• With a history of abdominal fistula, tracheoesophageal fistula, gastrointestinal perforation, or intra-abdominal abscess within the last 6 months prior to the start of the study treatment;
• Adverse events resulting from prior anti-tumor therapies should be assessed and graded according to the CTCAE 5.0 criteria, subjects whose AEs have not returned to Grade 1 or below;
• Has uncontrollable pleural, pericardial, or abdominal effusions;
• Has received allogeneic hematopoietic stem cell transplantation or organ transplantation.

The data will be published or presented for publications (poster, abstract,articles or papers) or any presentations.

After the trial completed

NCI is committed to sharing data in accordance with NIH policy