This trial is an open-label, multicenter phase Ib/II clinical study to evaluate the efficacy and safety of LBL-024 monotherapy or in combination with albumin-bound paclitaxel in patients with recurrent or metastatic triple negative breast cancer(TNBC).

The trial was divided into two phases.

Stage I (Phase Ib):

Part A: Monotherapy Period:In the phase Ib Part A monotherapy period, a small number of TNBC patients were planned to be enrolled to receive LBL-024 monotherapy.The safety, tolerability, and preliminary efficacy of LBL-024 monotherapy in this population will be assessed by the sponsor and investigator in combination.

Part B: Combination Drug Safety Run-In Period:If the safety and tolerability are good and there is preliminary efficacy in Part A,The investigator discussed with the sponsor to decide whether to continue the study in Part B of Phase Ib.Part B is designed to enroll a small number of TNBC patients to receive LBL-024 combination therapy.

Stage II (Phase II) ： If the safety and tolerability are good and there is preliminary efficacy in the first stage,The investigator discusses with the sponsor to decide whether to continue the co-administration expansion study, continue to enroll TNBC patients, and using a randomized, open, positive control trial design.

This study will enroll up to 220 subjects.

Inclusion Criteria:

1. Agree to follow the trial treatment regimen, visit schedule, laboratory test, and other requirements of the protocol, and voluntarily enroll in the study and sign the written informed consent.
2. At the time of signing the informed consent form, the age was ≥ 18 years old.
3. The Eastern Cooperative Oncology Group's physical status scoring standard (ECOG) is 0~1.
4. The expected survival time is at least 12 weeks.
5. According to the evaluation of RECIST 1.1 （Response Evaluation Criteria in Solid Tumours），the subjects enrolled have at least one measurable lesion.
6. Females of childbearing age are willing to take highly effective contraceptive measures From the signing of the informed consent form to within 6 months after the last administration of the trial drug; Women of childbearing age must have a negative pregnancy test within 7 days before the first trial drug is administered.Male patients are willing to take highly effective contraceptive measures From the signing of the informed consent form to within 6 months after the last administration of the trial drug,and do not donate sperm during this period.

Exclusion Criteria:

1. Use of immunomodulatory drugs within 2 weeks prior to first dose of study drug.

2. Patients who received live vaccination within 4 weeks before the first dose of study drug or who are scheduled to receive live vaccination during the study treatment period and within 4 weeks after the last dose.

3. Patients with clinically uncontrolled pleural effusion, peritoneal effusion, or pericardial effusion.

4. Active infection within 2 weeks prior to first dose of study drug.

5. Active infectious disease.

6. Women with plans for pregnancy,Or women who are pregnant or breastfeeding.

7. Active hepatitis B or active hepatitis C.

8. History of mental illness (interfering with understanding or giving informed consent), drug abuse, alcoholism, or drug addiction.

9. The investigator believes that the subject has other conditions that may affect compliance or are not suitable for participating in this study.

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