Phase II Study of HLX43 Monotherapy or Combined With Immune Checkpoint Inhibitors in Patients With Locally Advanced, Recurrent, or Metastatic Triple-negative Breast Cancer.

NCT07487519 | Not Yet Recruiting Phase 2

• 1 other identifier: HLX43-BC202
• Study Type: interventional
• Target: 180
• Locations: 1 country
• Sites: 1

Brief Summary

The study is being conducted to explore the reasonable dosage and evaluate the efficacy, safety and tolerability of HLX43 (Anti-PD-L1 ADC) as a monotherapy or in combination with immune checkpoint inhibitors in Subjects with locally advanced, recurrent or metastatic triple-negative breast cancer (TNBC).

Conditions

Breast Cancer (Triple Negative Breast Cancer (TNBC))

Outcome Measures

Primary Outcomes (2)

• ORR

  Objective response rate (ORR) (assessed by BICR according to the RECIST v1.1 criteria)

  up to 24 weeks

• PFS

  Defined as the time (in months) from randomization to the first confirmed and documented progressive disease or death (whichever occurs first) as assessed by BICR according to the RECIST v1.1 criteria.

  From date of randomization until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 10 months

Study Arms (6)

armA: HLX43 DOSE 1 in ≥2L TNBC

EXPERIMENTAL

Patients with good tolerability and well controlled disease will receive the treatment once every 3 weeks (Q3W), Until disease progression, initiation of a new anti-tumor therapy, death, emergence of intolerable toxicity, or withdrawal of informed consent (whichever occurs first)

Drug: HLX43 DOSE 1 IN ≥2L TNBC

armB: HLX43 DOSE 2 in ≥2L TNBC

EXPERIMENTAL

Patients with good tolerability and well controlled disease will receive the treatment once every 3 weeks (Q3W), Until disease progression, initiation of a new anti-tumor therapy, death, emergence of intolerable toxicity, or withdrawal of informed consent (whichever occurs first)

Drug: HLX43 DOSE 2 IN ≥2L TNBC

armC: HLX43 DOSE 1 in 1L TNBC

EXPERIMENTAL

Patients with good tolerability and well controlled disease will receive the treatment once every 3 weeks (Q3W), Until disease progression, initiation of a new anti-tumor therapy, death, emergence of intolerable toxicity, or withdrawal of informed consent (whichever occurs first)

Drug: HLX43 DOSE1 IN 1L TNBC

armD: HLX43 DOSE 2 in 1L TNBC

EXPERIMENTAL

Patients with good tolerability and well controlled disease will receive the treatment once every 3 weeks (Q3W), Until disease progression, initiation of a new anti-tumor therapy, death, emergence of intolerable toxicity, or withdrawal of informed consent (whichever occurs first)

Drug: HLX43 DOSE 2 IN 1L TNBC

armE: HLX43 DOSE 1+ HLX10 in 1L TNBC

EXPERIMENTAL

Patients with good tolerability and well controlled disease will receive the treatment once every 3 weeks (Q3W), Until disease progression, initiation of a new anti-tumor therapy, death, emergence of intolerable toxicity, or withdrawal of informed consent (whichever occurs first)

Drug: HLX43 DOSE 1 + HLX10

armF: HLX43 DOSE 2+ HLX10 in 1L TNBC

EXPERIMENTAL

Patients with good tolerability and well controlled disease will receive the treatment once every 3 weeks (Q3W), Until disease progression, initiation of a new anti-tumor therapy, death, emergence of intolerable toxicity, or withdrawal of informed consent (whichever occurs first)

Drug: HLX43 DOSE2 + HLX10

Interventions

HLX43 DOSE 1 IN ≥2L TNBC DRUG

Dose 1; HLX43 is an anti-PD-L1 monoclonal antibody conjugated with a novel high potency DNA topoisomerase I (topo I) inhibitor, with a drug-antibody-ratio (DAR) of 8.

armA: HLX43 DOSE 1 in ≥2L TNBC

HLX43 DOSE 2 IN ≥2L TNBC DRUG

Dose 2; HLX43 is an anti-PD-L1 monoclonal antibody conjugated with a novel high potency DNA topoisomerase I (topo I) inhibitor, with a drug-antibody-ratio (DAR) of 8.

armB: HLX43 DOSE 2 in ≥2L TNBC

HLX43 DOSE 1 + HLX10 DRUG

HLX43 is an anti-PD-L1 monoclonal antibody conjugated with a novel high potency DNA topoisomerase I (topo I) inhibitor, with a drug-antibody-ratio (DAR) of 8. HLX10 is a humanized anti-PD-1 monoclonal antibody that functions as an immune checkpoint inhibitor.

armE: HLX43 DOSE 1+ HLX10 in 1L TNBC

HLX43 DOSE1 IN 1L TNBC DRUG

HLX43 is an anti-PD-L1 monoclonal antibody conjugated with a novel high potency DNA topoisomerase I (topo I) inhibitor, with a drug-antibody-ratio (DAR) of 8.

armC: HLX43 DOSE 1 in 1L TNBC

HLX43 DOSE 2 IN 1L TNBC DRUG

HLX43 is an anti-PD-L1 monoclonal antibody conjugated with a novel high potency DNA topoisomerase I (topo I) inhibitor, with a drug-antibody-ratio (DAR) of 8.

armD: HLX43 DOSE 2 in 1L TNBC

HLX43 DOSE2 + HLX10 DRUG

HLX43 is an anti-PD-L1 monoclonal antibody conjugated with a novel high potency DNA topoisomerase I (topo I) inhibitor, with a drug-antibody-ratio (DAR) of 8. HLX10 is a humanized anti-PD-1 monoclonal antibody that functions as an immune checkpoint inhibitor.

armF: HLX43 DOSE 2+ HLX10 in 1L TNBC

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Voluntary written informed consent obtained before any study procedures.
• Age ≥ 18 years at consent; no gender restriction.
• Histopathologically confirmed TNBC: ER \< 1%, PR \< 1%, HER2 IHC 0/1+/2+ with no FISH amplification.
• Phase I: Recurrent or metastatic TNBC after ≥1 prior line of standard systemic therapy.
• Phase II: Unresectable locally advanced, recurrent, or metastatic TNBC with no prior systemic anti-cancer therapy for this stage (palliative radiotherapy to metastases allowed; neoadjuvant/adjuvant therapy permitted if completed ≥6 months before recurrence/metastasis).
• At least one RECIST v1.1-measurable lesion documented within 4 weeks before randomization.
• Note: Target lesions must not be in irradiated fields or the CNS. If only measurable lesion is irradiated, imaging must confirm progression post-radiotherapy.
• Archival FFPE tumor tissue (≤6 months old, ≤2 years max) for PD-L1 testing; fresh biopsy acceptable if archival tissue is unavailable or inadequate.
• Note: Specimens must be non-irradiated FFPE blocks/slides with pathology report confirming malignancy and adequacy.
• Washout: ≥3 weeks (or 5 half-lives, whichever is shorter) after major surgery, radiotherapy (except palliative bone RT), chemotherapy, targeted therapy, or immunotherapy; ≥1 week after minor surgery or anti-tumor TCM. All treatment-related AEs resolved to CTCAE v6.0 Grade ≤1 (stable Grade 2 peripheral neuropathy and alopecia exempted).
• ECOG PS 0-1, assessed ≤7 days before randomization.
• Life expectancy \>3 months.
• Adequate hematologic, hepatic, and renal function per labs ≤7 days before randomization.

You may not qualify if:

• Prior topoisomerase I-targeting therapy (e.g., irinotecan, topotecan, or ADCs).
• Second primary malignancy within 2 years before randomization (except cured carcinoma in situ or stage I tumors).
• Prior grade ≥3 immune-related adverse event during immunotherapy.
• Uncontrolled, recurrent malignant pleural, pericardial, or ascitic effusions requiring repeated drainage.
• Active CNS metastases, spinal cord compression, or carcinomatous meningitis.
• Clinically significant pulmonary impairment.
• Uncontrolled cardiovascular or cerebrovascular disease .
• Active systemic infection requiring IV antibiotics within 2 weeks before randomization.
• Moderate or strong CYP2D6/CYP3A inhibitor or inducer use within 2 weeks before randomization.
• Systemic corticosteroids (\>10 mg/day prednisone equivalent) or other immunosuppressants within 2 weeks before randomization .
• Active or suspected autoimmune disease .
• Live or attenuated live vaccine within 4 weeks before randomization.
• Hypersensitivity to mAbs, large-molecule biologics, or drug formulation excipients.
• Active pulmonary tuberculosis.
• Known immunodeficiency.

Sponsors & Collaborators

• Shanghai Henlius Biotech: lead

Study Sites (1)

Harbin Medical University Affiliated Cancer Hospital

Harbin, Heilongjiang, 150081, China

Location

MeSH Terms

Conditions

Breast Neoplasms; Triple Negative Breast Neoplasms

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Central Study Contacts

Xiangyun Wang

CONTACT

86-13391626886; Xixangyun_Wang@henlius.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 17, 2026
• First Posted: March 23, 2026
• Study Start: April 25, 2026
• Primary Completion (Estimated): May 15, 2027
• Study Completion (Estimated): May 22, 2028
• Last Updated: March 23, 2026

Record last verified: 2026-03

Locations

CN (1)