A Study of BL-B01D1 Plus an Anti-PD-1 Antibody Versus Nab-paclitaxel Plus an Anti-PD-1 Antibody in Patients With Previously Untreated, Locally Advanced, Inoperable or Metastatic Triple-Negative Breast Cancer Whose Tumors Express PD-L1 (PANKU-Breast04)

A Phase III Randomized Controlled Clinical Study of BL-B01D1 Plus an Anti-PD-1 Antibody Versus Nab-paclitaxel Plus an Anti-PD-1 Antibody in Patients With Previously Untreated, Locally Advanced, Inoperable or Metastatic Triple-Negative Breast Cancer Whose Tumors Express PD-L1 (PANKU-Breast04)

This trial is a registrational Phase III, randomized, open-label, multicenter study designed to compare the efficacy and safety of BL-B01D1 in combination with a PD-1 monoclonal antibody versus nab-paclitaxel in combination with a PD-1 monoclonal antibody in patients with PD-L1-positive, previously untreated, inoperable locally advanced or recurrent metastatic triple-negative breast cancer.

Study Overview

• Status: Not yet recruiting
• Conditions: Triple-Negative Breast Cancer (TNBC)
• Intervention / Treatment: Drug: BL-B01D1; Drug: PD-1 monoclonal antibody; Drug: Nab-paclitaxel

• Study Type: Interventional
• Enrollment (Estimated): 436
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Sa Xiao, PHD; Phone Number: +8615013238943; Email: xiaosa@baili-pharm.com

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China
      • Fudan University Shanghai Cancer Center
      • Principal Investigator: Jian Zhang
      • Principal Investigator: Jiong Wu
      • Contact: Jiong Wu; Phone Number: 021-64175590-73546; Email: wujiong1122@vip.sina.xn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Voluntarily sign the informed consent form and agree to comply with the protocol requirements;
2. Female patients aged 18 to 75 years;
3. Expected survival time ≥ 3 months;
4. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1;
5. Pathologically confirmed recurrent or metastatic triple-negative breast cancer;
6. Confirmed PD-L1 expression positivity by central laboratory testing;
7. No prior systemic anti-tumor therapy in the advanced/recurrent or metastatic setting;
8. Agree to provide archived tumor tissue specimens (surgical specimens) or fresh tissue samples from primary or metastatic lesions obtained within 3 years;
9. Must have at least one measurable lesion as defined by RECIST v1.1;
10. Toxicities from prior anti-tumor therapy must have recovered to ≤ Grade 1 as defined by NCI-CTCAE v6.0;
11. No severe cardiac dysfunction, with left ventricular ejection fraction (LVEF) ≥ 50%;
12. Organ function levels must meet the protocol-specified requirements;
13. Urine protein ≤ 1+ or < 1000 mg/24 h;
14. For premenopausal women of childbearing potential, a pregnancy test (serum) must be performed within 7 days before starting treatment, and pregnancy must be ruled out; patients must not be lactating. All enrolled patients (regardless of sex) must use adequate barrier contraception throughout the entire treatment period and for 7 months after the end of treatment.

Exclusion Criteria:

1. Received surgery, radical radiotherapy, or immunotherapy within 4 weeks before the first dose;
2. Prior exposure to ADC drugs with topoisomerase I inhibitor payload;
3. Prior treatment with other T-cell receptor-targeting agents (excluding PD-1/PD-L1);
4. Use of immunomodulators within 14 days before the first study drug dose;
5. History of severe cardiac or cerebrovascular disease;
6. Receiving chronic systemic corticosteroids at >10 mg/day prednisone before the first dose;
7. Active autoimmune or inflammatory disease;
8. Any thrombotic event within 6 months before randomization;
9. Prolonged QTc, complete left bundle branch block, or similar;
10. Active malignancy diagnosed within 3 years before randomization;
11. Hypertension uncontrolled by two antihypertensives;
12. Poorly controlled diabetes/hyperglycemia;
13. History of steroid-treated ILD/interstitial pneumonitis;
14. Concurrent lung disease causing clinically significant respiratory impairment;
15. Active CNS metastases;
16. Severe infection within 4 weeks before randomization;
17. Massive or symptomatic serosal effusion;
18. Severe non-healing wound, ulcer, or fracture within 4 weeks before consent;
19. Clinically significant bleeding or bleeding tendency within 4 weeks before consent;
20. Inflammatory bowel disease, extensive bowel resection, immune enteritis, bowel obstruction, or chronic diarrhea;
21. Allergy or contraindication to the study drug;
22. History of autologous/allogeneic stem cell transplantation;
23. HIV antibody positive, active HBV, or active HCV;
24. History of severe neurological or psychiatric illness;
25. Received or planning to receive live vaccine within 28 days before randomization;
26. Other conditions rendering the patient unsuitable per investigator's judgment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BL-B01D1+PD-1 monoclonal antibody; Participants receive BL-B01D1+PD-1 monoclonal antibody in the first cycle (3 weeks). Participants with clinical benefit could receive additional treatment for more cycles. The administration will be terminated because of disease progression or intolerable toxicity occurring or other reasons.	Drug: BL-B01D1; Administration by intravenous infusion for a cycle of 3 weeks.; Other Names: BMS-986507; iza-bren; izalontamab brengitecan; Drug: PD-1 monoclonal antibody; Administration by intravenous infusion for a cycle of 3 weeks.
Active Comparator: nab-paclitaxel+PD-1 monoclonal antibody; Participants receive nab-paclitaxel+PD-1 monoclonal antibody in the first cycle (3 weeks). Participants with clinical benefit could receive additional treatment for more cycles. The administration will be terminated because of disease progression or intolerable toxicity occurring or other reasons.	Drug: PD-1 monoclonal antibody; Administration by intravenous infusion for a cycle of 3 weeks.; Drug: Nab-paclitaxel; Administration by intravenous infusion for a cycle of 3 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BICR-assessed Progression-free Survival (PFS)	Progression-free survival (PFS) as assessed by BICR is defined as the time between the date subjects were randomized and the first observation of disease progression (based on BICR's image-based assessment) or death.	Up to approximately 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AUC0-t	AUC0-t is defined as area under the serum concentration-time curve from time 0 to the time of the last measurable concentration.	Up to approximately 24 months
Cmax	Maximum serum concentration (Cmax) of BL-B01D1 will be investigated.	Up to approximately 24 months
T1/2	Half-life (T1/2) of BL-B01D1 will be investigated.	Up to approximately 24 months
CL (Clearance)	CL in the serum of BL-B01D1 per unit of time will be investigated.	Up to approximately 24 months
Objective Response Rate (ORR)	Objective response rate (ORR) is defined as the number of CR and PR in the treatment and control groups divided by the number of that group in the full analysis set (FAS).	Up to approximately 24 months
Disease Control Rate (DCR)	Disease Control Rate (DCR) : Percentage of all randomized subjects who rated the best overall response (BOR) as complete response (CR), partial response (PR), and disease stabilization (SD) according to RECIST 1.1 criteria.	Up to approximately 24 months
Duration of Response (DOR)	Duration of Response (DOR) : defined as the period from the date when tumor response is first recorded to the date when objective tumor progression is first recorded or the date of death.	Up to approximately 24 months
Treatment Emergent Adverse Event (TEAE)	TEAE is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally emerging, or any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a pre-existing condition during the treatment of BL-B01D1. The type, frequency and severity of TEAE will be evaluated during the treatment of BL-B01D1.	Up to approximately 24 months
Tmax	Time to maximum serum concentration (Tmax) of BL-B01D1 will be investigated.	Up to approximately 24 months
Ctrough	Ctrough is defined as the lowest serum concentration of BL-B01D1 prior to the next dose will be administered.	Up to approximately 24 months
Overall Survival (OS)	Overall survival (OS) is defined as the time between the day the subject is randomized and the subject's death.	Up to approximately 24 months
Time to Response (TTR)	Time to Response (TTR) is defined as the time from randomization to the first documented response (CR or PR) according to RECIST v1.1 criteria.	Up to approximately 24 months
Investigator-assessed Progression-free Survival (PFS)	Investigator-assessed progression-free survival (PFS) per RECIST v1.1 is defined as the time from treatment initiation until the first documented disease progression according to RECIST v1.1 criteria, or death from any cause, whichever occurs first, as determined by the local treating investigator.	Up to approximately 24 months
Anti-drug Antibody (ADA)	Frequency of anti-BL-B01D1 antibody (ADA) will be investigated.	Up to approximately 24 months
Neutralizing Antibody(NAb)	Frequency of anti-BL-B01D1 neutralizing antibodies will be investigated.	Up to approximately 24 months

Collaborators and Investigators

• Sponsor: Sichuan Baili Pharmaceutical Co., Ltd.
• Collaborators: Baili-Bio (Chengdu) Pharmaceutical Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): December 1, 2029
• Study Completion (Estimated): December 1, 2029

Study Registration Dates

• First Submitted: July 20, 2026
• First Submitted That Met QC Criteria: July 22, 2026
• First Posted (Actual): July 28, 2026

Study Record Updates

• Last Update Posted (Actual): July 28, 2026
• Last Update Submitted That Met QC Criteria: July 22, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Breast Neoplasms; Skin and Connective Tissue Diseases; Triple Negative Breast Neoplasms; 130-nm albumin-bound paclitaxel; spartalizumab
• Other Study ID Numbers: BL-B01D1-325

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No