Metastatic Breast CancerPhase 3NCT07071337
A Study of SKB264 Versus Investigator's Choice of Chemotherapy in Subjects With Unresectable Locally Advanced, Relapsed, or Metastatic HR+/HER2- Breast Cancer Who Have Previously Failed Endocrine Therapy
A Phase 3 study testing SKB264, Nab-paclitaxel and Paclitaxel in people with Metastatic Breast Cancer, run by Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. at 2 sites in China.
Trial summary
The purpose of this study is to evaluate the efficacy and safety of SKB264 in patients with unresectable locally advanced, recurrent, or metastatic HR+/HER2- breast cancer who have previously failed endocrine therapy. Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Metastatic Breast Cancer
- What is being tested?
- SKB264, Nab-paclitaxel and Paclitaxel
- Type of treatment
- Pill or oral medicine, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 430 participants
- Where
- 2 sitesChina
- Study dates
- 18 Jul 2025to Feb 2031
- Phase
- Phase 3
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged ≥ 18 and ≤ 75 years at the time of signing the ICF, male or female;
- Histologically and/or cytologically confirmed HR+/HER2- BC based on pathological reports from the most recent biopsy or other pathological specimens;
- Subjects must have radiologically documented disease progression during or after the most recent treatment prior to enrollment;
- No prior systemic chemotherapy for locally advanced, relapsed, or metastatic stages. Subjects who previously received adjuvant/neoadjuvant chemotherapy and progressed >6 months after completion of the last chemotherapy treatment will be allowed for study inclusion;
- The investigator assessed that the patient could not continue to benefit from endocrine therapy and was suitable for receiving first-line chemotherapy;
- Able to provide recently newly obtained or archival tumor tissue sections at or after diagnosis of relapsed or metastatic tumor within the recent prior to randomization;
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- At least one measurable lesion per RECIST v1.1；
- Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 1 with no worsening within 2 weeks prior to randomization;
- Life expectancy of ≥ 12 weeks;
- Suitable to receive one of the chemotherapy regimens listed in the investigator's choice of chemotherapy (paclitaxel, nab-paclitaxel, capecitabine) as assessed by the investigator;
- Adequate organ and bone marrow function;
- Having recovered from all toxicities due to prior treatment;
- Use of effective medical contraception during study treatment and for 6 months after the end of dosing for female subjects of childbearing potential and male subjects with partners of childbearing potential;
- Willingness to participate in the study, sign the ICF, and comply with the protocol-specified visits and relevant procedures.
Who cannot join
- Subjects with locally advanced breast cancer suitable for curative therapy at study enrollment;
- Other malignancies (except those tumors cured by local treatment, such as basal cell carcinoma of skin, squamous cell carcinoma of skin, carcinoma in situ of the cervix) within 3 years prior to randomization;
- Subiects with known meningeal metastases, brainstem metastases, spinal cord metastases and/or compression or active centralnervous system (CNS) metastases.
- Presence of any serious cardiovascular and cerebrovascular diseases or cardiovascular and cerebrovascular risk factors;
- History of (noninfectious) interstitial lung disease (ILD)/noninfectious pneumonitis requiring steroid therapy and current ILD/noninfectious pneumonitis, or suspected ILD/noninfectious pneumonitis at screening that cannot be excluded by imaging;
- Clinically serious lung injuries caused by lung diseases;
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- Serious infection within 4 weeks prior to randomization, including but not limited to complications requiring hospitalization, sepsis, or severe pneumonia; active infection requiring systemic anti-infective therapy within 2 weeks prior to randomization;
- Documented severe dry eye syndrome, severe meibomian gland dysfunction and/or blepharitis, or history of severe corneal disorders that prevent/delay corneal healing;
- History of esophagogastric varices, severe ulcers, gastric perforation, gastrointestinal obstruction, intra-abdominal abscess, or acute gastrointestinal bleeding within 6 months prior to randomization;
- Active hepatitis B (hepatitis B surface antigen positive and HBV-DNA ≥ 500 IU/mL or above the ULN, whichever is higher) or hepatitis C (hepatitis C antibody positive and HCV-RNA above the ULN);
- Positive result of human immunodeficiency virus (HIV) test or history of acquired immunodeficiency syndrome (AIDS); known active syphilis infection;
- 12 Known hypersensitivity to SKB264 or investigator's choice chemotherapy or any of its excipients, including but not limited to polysorbate-20, or history of severe hypersensitivity reaction to other monoclonal antibodies;
- Known history of allogeneic organ transplantation and allogeneic hematopoietic stem cell transplantation.
- Pregnant or lactating women;
- Prior TROP2-targeted therapy or any treatment containing chemotherapeutic agents targeting topoisomerase I (including antibody-drug conjugates [ADCs]);
- Live vaccines within 4 weeks prior to randomization or scheduled to receive live vaccines during study treatment;
- Receipt of the following therapies prior to randomization: a)Major surgery within 4 weeks prior or expected major surgery during the study; b)Radiation therapy within 2 weeks prior (extensive radiation therapy including radiopharmaceuticals within 4 weeks prior); c)Any immunotherapy, biological therapy, or other investigational drugs within 4 weeks or 5 half-lives of prior drug use (whichever is shorter) (bisphosphonates or RANK-L inhibitors for bone metastases are permitted prior to randomization); or traditional Chinese medicine with approved anti-tumor indications, small molecule targeted therapy, or endocrine therapy within 2 weeks prior.
- Rapid deterioration of the condition, e.g., significant changes in performance status, etc., during the screening process.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
China2 sites, 2 recruiting
- Recruiting
The Fifth Medical Center of the Chinese PLA General Hospital
Beijing, Beijing Municipality, 100039
Zefei Jiang, 86-010-66947175, jzf_cscobc@csco.org.cn
- Recruiting
Sun Yat-sen University Cancer Center
Guangzhou, Guangdong, 510060
Shusen Wang, 86-020-87342491, wangshs@sysucc.org.cn
About this study
Official title: A Randomized, Open-label, Multicenter Phase III Clinical Study of SKB264 Versus Investigator's Choice of Chemotherapy in Subjects With Unresectable Locally Advanced, Relapsed, or Metastatic Hormone Receptor-positive (HR+)/Human Epidermal Growth Factor Receptor 2-negative (HER2-) Breast Cancer Who Have Previously Failed Endocrine Therapy
The purpose of this study is to evaluate the efficacy and safety of SKB264 in patients with unresectable locally advanced, recurrent, or metastatic HR+/HER2- breast cancer who have previously failed endocrine therapy.
Read the detailed description
This is a randomized, open-label, multicenter phase 3 clinical study to evaluate the efficacy and safety of SKB264 monotherapy versus investigator's choice of chemotherapy (ICC) in subjects with unresectable locally advanced, recurrent, or metastatic HR+/HER2- breast cancer who had failed at least one line of systemic chemotherapy and have not recieved systemic chemotherapy for locally advanced, relapsed, or metastatic stages.
- Conditions
- Metastatic Breast Cancer
- Being tested
- SKB264, Nab-paclitaxel, Paclitaxel, Capecitabine
- Keywords
- SKB264, HR+/HER2- breast cancer
- Medical subject headings
- Breast Neoplasms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SKB264Drug
5mg/kg, IV on Day 1 and Day 15 of each 28 day cycle
Nab-paclitaxelDrug
100 mg/m^2, IV, on Days 1, 8, and 15 every 4 weeks
PaclitaxelDrug
90 mg/m^2, IV, on Days 1, 8, and 15 every 4 weeks; or 80 mg/m^2, IV, weekly, every 3 weeks
CapecitabineDrug
1000-1250 mg/m^2, orally, Days 1-14, twice daily, every 3 weeks
| Study group | Role | What they receive |
|---|---|---|
| SKB264 | Experimental | Not described Receives: Drug: SKB264 |
| Investigator's Choice of Chemotherapy | Active comparator | Nab-paclitaxel, paclitaxel or capecitabine will be administered and managed according to the investigator's clinical judgment, guided by clinical practice. Receives: Drug: Nab-paclitaxel; Drug: Paclitaxel; Drug: Capecitabine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Progression Free Survival (PFS) assessed by Blinded Independent Central Review (BICR)
PFS is defined as the time from randomization to the first documented disease progression per RECIST 1.1 based on BICR or death due to any cause, whichever occurs first
Measured: Randomization up to approximately 24 months
Secondary outcomes (12)
Overall Survival (OS)
OS is defined as the time from randomization until the date of death due to any cause
Measured: Randomization up to approximately 67 months
Progression-Free Survival (PFS) assessed by Investigator
PFS is defined as the time from randomization to the first documented disease progression per RECIST 1.1 based on investigator or death due to any cause, whichever occurs first.
Measured: Randomization up to approximately 24 months
Objective Response Rate (ORR)
ORR is defined as the percentage of patients who achieve complete response(CR) or partial response (PR), as assessed by BICR/investigator per RECIST 1.1
Measured: Randomization up to approximately 24 months
Disease control rate (DCR)
DCR is defined as the percentage of patients who achieve CR, PR or stable disease (SD), as assessed by BICR/ investigator per RECIST 1.1
Measured: Randomization up to approximately 24 months
Duration of Response (DoR)
DoR is defined as the time from the date of first documented CR or PR until date of documented disease progression per RECIST 1.1, as assessed by BICR/investigator or death due to any cause, whichever occurs first.
Measured: Randomization up to approximately 24 months
Time to Response (TTR)
TTR is defined as the time from the date of randomization until the first documentation of CR or PR as assessed by BICR/investigator per RECIST 1.1.
Measured: Randomization up to approximately 24 months
AEs and SAEs
Incidence and severity of AEs and SAEs (per CTCAE 5.0), and clinically significant abnormal laboratory findings
Measured: AEs should be collected from signing the informed consent form (ICF) until 30 days after the last dose
Mean change from baseline in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30)
To assess the impact of SKB264 on disease related symptoms and health related quality of life (HRQoL) in this patient population
Measured: Randomization up to approximately 24 months
Mean change from baseline in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Breast Cancer Module 23 (EORTC QLQ-BR23)
To assess the impact of SKB264 on disease related symptoms and health related quality of life (HRQoL) in this patient population
Measured: Randomization up to approximately 24 months
Anti-drug Antibodies (ADA) for SKB264
Immunogenicity test results and titer values of SKB264
Measured: Day1 and Day15 of Cycle 1 (each cycle is 28 days), Day1 of Cycle 3, Cycle 6, and so on (every 3 cycles), up to approximately 24 months
Maximum observed plasma concentration (Cmax) of SKB264-ADC, SKB264-TAB and free KL610023
To assess the pharmacokinetic (PK) profile of SKB264.
Measured: Day1 and Day15 of Cycle 1 (each cycle is 28 days), Day1 of Cycle 3, Cycle 6, and so on (every 3 cycles), up to approximately 24 months
Minimum observed plasma concentration (Cmin) of SKB264-ADC, SKB264-TAB and free KL610023
To assess the pharmacokinetic (PK) profile of SKB264.
Measured: Day1 and Day15 of Cycle 1 (each cycle is 28 days), Day1 of Cycle 3, Cycle 6, and so on (every 3 cycles), up to approximately 24 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Jul 2025
- Study start18 Jul 2025
- Primary completionJul 2027 (estimated)
- Study completionFeb 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metastatic Breast CancerStudies of the same condition, open and under way.
- More trials run by Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Participants will be randomised in a 1:1 ratio to one of two intervention groups
- Masking
- None (open label)
- Enrolment
- 430 participants (estimated)
Sponsor and investigators
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07071337
- Sponsor's protocol ID
- SKB264-Ⅲ-13
- Status last verified
- May 2026
- First submitted
- 19 Jun 2025
- Last updated
- 8 May 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 8 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized, Open-label, Multicenter Phase III Clinical Study of SKB264 Versus Investigator's Choice of Chemotherapy in Subjects With Unresectable Locally Advanced, Relapsed, or Metastatic Hormone Receptor-positive (HR+)/Human Epidermal Growth Factor Receptor 2-negative (HER2-) Breast Cancer Who Have Previously Failed Endocrine Therapy
- ClinicalTrials.gov ID
- NCT07071337
- Acronym / sponsor ID
- SKB264-Ⅲ-13
- Conditions
- Metastatic Breast Cancer
- Keywords
- SKB264, HR+/HER2- breast cancer
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 430 participants (estimated)
- Lead sponsor
- Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 18 Jul 2025 (actual)
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Feb 2031 (estimated)
- First posted
- 17 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to evaluate the efficacy and safety of SKB264 in patients with unresectable locally advanced, recurrent, or metastatic HR+/HER2- breast cancer who have previously failed endocrine therapy.
Detailed description
This is a randomized, open-label, multicenter phase 3 clinical study to evaluate the efficacy and safety of SKB264 monotherapy versus investigator's choice of chemotherapy (ICC) in subjects with unresectable locally advanced, recurrent, or metastatic HR+/HER2- breast cancer who had failed at least one line of systemic chemotherapy and have not recieved systemic chemotherapy for locally advanced, relapsed, or metastatic stages.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants will be randomised in a 1:1 ratio to one of two intervention groups
| Arm | Type | Receives |
|---|---|---|
| SKB264 | Experimental | Drug: SKB264 |
| Investigator's Choice of Chemotherapy | Active comparator | Drug: Nab-paclitaxel, Drug: Paclitaxel, Drug: CapecitabineNab-paclitaxel, paclitaxel or capecitabine will be administered and managed according to the investigator's clinical judgment, guided by clinical practice. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (14 listed)
- Aged ≥ 18 and ≤ 75 years at the time of signing the ICF, male or female;
- Histologically and/or cytologically confirmed HR+/HER2- BC based on pathological reports from the most recent biopsy or other pathological specimens;
- Subjects must have radiologically documented disease progression during or after the most recent treatment prior to enrollment;
- No prior systemic chemotherapy for locally advanced, relapsed, or metastatic stages. Subjects who previously received adjuvant/neoadjuvant chemotherapy and progressed >6 months after completion of the last chemotherapy treatment will be allowed for study inclusion;
- The investigator assessed that the patient could not continue to benefit from endocrine therapy and was suitable for receiving first-line chemotherapy;
Key exclusion criteria (18 listed)
- Subjects with locally advanced breast cancer suitable for curative therapy at study enrollment;
- Other malignancies (except those tumors cured by local treatment, such as basal cell carcinoma of skin, squamous cell carcinoma of skin, carcinoma in situ of the cervix) within 3 years prior to randomization;
- Subiects with known meningeal metastases, brainstem metastases, spinal cord metastases and/or compression or active centralnervous system (CNS) metastases.
- Presence of any serious cardiovascular and cerebrovascular diseases or cardiovascular and cerebrovascular risk factors;
- History of (noninfectious) interstitial lung disease (ILD)/noninfectious pneumonitis requiring steroid therapy and current ILD/noninfectious pneumonitis, or suspected ILD/noninfectious pneumonitis at screening that cannot be excluded by imaging;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SKB2645mg/kg, IV on Day 1 and Day 15 of each 28 day cycle | Drug | SKB264 |
| Nab-paclitaxel100 mg/m^2, IV, on Days 1, 8, and 15 every 4 weeks | Drug | Investigator's Choice of Chemotherapy |
| Paclitaxel90 mg/m^2, IV, on Days 1, 8, and 15 every 4 weeks; or 80 mg/m^2, IV, weekly, every 3 weeks | Drug | Investigator's Choice of Chemotherapy |
| Capecitabine1000-1250 mg/m^2, orally, Days 1-14, twice daily, every 3 weeks | Drug | Investigator's Choice of Chemotherapy |
Primary outcome
Progression Free Survival (PFS) assessed by Blinded Independent Central Review (BICR)
Time frame: Randomization up to approximately 24 months
PFS is defined as the time from randomization to the first documented disease progression per RECIST 1.1 based on BICR or death due to any cause, whichever occurs first
12 secondary outcomes
Overall Survival (OS)
Time frame: Randomization up to approximately 67 months
Progression-Free Survival (PFS) assessed by Investigator
Time frame: Randomization up to approximately 24 months
Objective Response Rate (ORR)
Time frame: Randomization up to approximately 24 months
Disease control rate (DCR)
Time frame: Randomization up to approximately 24 months
Duration of Response (DoR)
Time frame: Randomization up to approximately 24 months
Time to Response (TTR)
Time frame: Randomization up to approximately 24 months
AEs and SAEs
Time frame: AEs should be collected from signing the informed consent form (ICF) until 30 days after the last dose
Mean change from baseline in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30)
Time frame: Randomization up to approximately 24 months
Mean change from baseline in the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Breast Cancer Module 23 (EORTC QLQ-BR23)
Time frame: Randomization up to approximately 24 months
Anti-drug Antibodies (ADA) for SKB264
Time frame: Day1 and Day15 of Cycle 1 (each cycle is 28 days), Day1 of Cycle 3, Cycle 6, and so on (every 3 cycles), up to approximately 24 months
Maximum observed plasma concentration (Cmax) of SKB264-ADC, SKB264-TAB and free KL610023
Time frame: Day1 and Day15 of Cycle 1 (each cycle is 28 days), Day1 of Cycle 3, Cycle 6, and so on (every 3 cycles), up to approximately 24 months
Minimum observed plasma concentration (Cmin) of SKB264-ADC, SKB264-TAB and free KL610023
Time frame: Day1 and Day15 of Cycle 1 (each cycle is 28 days), Day1 of Cycle 3, Cycle 6, and so on (every 3 cycles), up to approximately 24 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 May 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing SKB264, Nab-paclitaxel and Paclitaxel in people with Metastatic Breast Cancer, run by Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd. at 2 sites in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 8 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Yina Diao (86-028-67252634, diaoyina@kelun.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Progression Free Survival (PFS) assessed by Blinded Independent Central Review (BICR) (time frame: Randomization up to approximately 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 May 2026.