Treatment for recurrent or metastatic HER2-negative breast cancer

A Phase 2 Clinical Study of SKB264 With/Without KL-A167 in Patients With Unresectable Locally Advanced, Recurrent or Metastatic HER2-negative Breast Cancer Who Have Not Received Prior Systemic Therapy

Phase 2 Interventional Sichuan Kelun Pharmaceutical Research Institute Co., Ltd. · NCT05445908

This study is testing a new treatment called SKB264, alone or with another drug, to see if it can help people with hard-to-treat breast cancer that has come back or spread.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment175 (estimated)
Ages18 Years to 75 Years
SexAll
SponsorSichuan Kelun Pharmaceutical Research Institute Co., Ltd. Industry-sponsored
Drugs / interventionschemotherapy, prednisone
Locations2 sites (Changsha, Hunan and 1 other locations)
Trial IDNCT05445908 on ClinicalTrials.gov

What this trial studies

This study evaluates the safety, tolerability, and preliminary effectiveness of SKB264 alone or in combination with KL-A167 in patients with unresectable locally advanced, recurrent, or metastatic triple-negative breast cancer (TNBC) and hormone receptor-positive/HER2-negative breast cancer (HR+/HER2- BC). The trial is divided into three parts: an exploratory phase for TNBC, a randomized treatment phase for TNBC, and a randomized treatment phase for HR+/HER2- BC. Participants will receive either SKB264 alone or in combination with KL-A167 to assess the potential benefits of the combination therapy.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 to 75 with a diagnosis of unresectable locally advanced, recurrent, or metastatic TNBC or HR+/HER2- BC who have not received prior systemic chemotherapy for their condition.

Not a fit: Patients with only skin or bone lesions or those who have received prior systemic chemotherapy for their advanced disease may not benefit from this study.

Why it matters

Potential benefit: If successful, this treatment could provide a new therapeutic option for patients with difficult-to-treat breast cancer subtypes.

How similar studies have performed: While this approach is being explored in this trial, similar studies have shown promise in targeting breast cancer, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Males or females aged ≥ 18 and ≤ 75 years at the time of signing the informed consent form (ICF);
2. Histological and/or cytological diagnosis of TNBC or HR+/HER2- BC based on pathology reports on recent biopsy samples or other pathological samples (central laboratory confirmation is not required);
3. Patients have not received prior systemic chemotherapy for locally advanced, recurrent and metastatic disease;
4. Ability to provide fresh or archival tumor tissue for biomarker testing and analysis;
5. Patients with at least one measurable lesion per RECIST v1.1 criteria, and patients with only skin or bone lesions cannot be enrolled;
6. Patients with an Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 with an expected survival of ≥ 12 weeks;
7. Adequate organ and bone marrow function;
8. Patients must recover from all toxicities due to prior treatment (recovery to ≤ Grade 1 based on CTCAE v5.0 assessment, or meeting the inclusion criteria in the protocol) with the exception of alopecia and vitiligo;
9. Female subjects of childbearing potential and male patients with partners of childbearing potential who use effective medical contraception during the study treatment period and for 6 months after the end of dosing (see Appendix for specific contraceptive measures);
10. Patients voluntarily participate in the study, sign the ICF, and will be able to comply with the protocol-specified visits and relevant procedures.

Exclusion Criteria:

1. History of other malignancies;
2. Patients with a history of central nervous system (CNS) metastases or current CNS metastases.
3. Imaging (CT or MRI) shows that the tumor has invaded large blood vessels or the investigator judges that the tumor is likely to invade important blood vessels and cause fatal hemorrhage during the follow-up study;
4. Received any systemic immune-stimulatory agents within 4 weeks prior to the first dose of study; Received any traditional Chinese medicine for approved anti-tumor indications within 2 weeks prior to the first dose of study;
5. Received other clinical investigational drugs within 4 weeks or major surgery within 4 weeks prior to the first dose of the study treatment;
6. Patients who required systemic corticosteroids (\> 10 mg/day prednisone or equivalent; low-dose corticosteroids are allowed, such as ≤10 mg/day prednisone or equivalent, if the dose is stable for 4 weeks), or other immunosuppressive therapy within 2 weeks prior to the first dose. Steroids are allowed as prophylaxis for hypersensitivity reactions;
7. Patients who occurred arteriovenous thrombosis within 6 months prior to the first dose of study treatment,Such as cerebrovascular accidents, deep vein thrombosis, and pulmonary embolism, etc.
8. Prior treatment with a TROP2-targeted drug or checkpoint inhibitor ;
9. Serious or uncontrolled cardiac disease or clinical symptoms requiring treatment;
10. Patients with (noninfectious) interstitial lung disease (ILD) or history of pneumonia requiring steroid therapy; patients with serious pulmonary function impairment due to lung disease;
11. Uncontrolled systemic disease as judged by the investigator, included uncontrolled hypertension, uncontrolled diabetes, pesence of pleural effusion, pericardial effusion, or ascites that is clinically symptomatic or requires repeated drainage;
12. Active autoimmune disease requiring systemic treatment within the past 2 years;
13. Active hepatitis B or hepatitis C; known history of positive human immunodeficiency virus (HIV) test or known acquired immunodeficiency syndrome (AIDS); positive syphilis antibody test;
14. Known hypersensitivity to the study drug or any of its components, or severe allergic reactions to other monoclonal antibodies;
15. Pregnant or lactating women;
16. Any patient whose condition deteriorates rapidly during the screening process prior to the first dose, such as severe changes in performance status, unstable pain requiring adjustment of analgesic therapy, etc;
17. Other circumstances that, in the opinion of the investigator, are not appropriate for participation in this study.

Where this trial is running

Changsha, Hunan and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Triple-negative Breast Cancer and HR+/HER2- BC
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.