Study of SKB264 for Locally Advanced, Recurrent or Metastatic HR+/HER2- Breast Cancer

A Randomized, Open-label, Multicenter Phase 3 Study of SKB264 Versus Treatment of Physician's Choice (TPC) in Patients With Unresectable Locally Advanced, Recurrent or Metastatic HR+/HER2- Breast Cancer Who Had Failed at Least One Line of Chemotherapy

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.

Study Overview

• Status: Recruiting
• Conditions: Metastatic Breast Cancer
• Intervention / Treatment: Drug: SKB264; Drug: Eribulin; Drug: Capecitabine; Drug: Gemcitabine; Drug: Vinorelbine

Detailed Description

This is a randomized, open-label, multicenter Phase 3 clinical study to evaluate SKB264 monotherapy versus Treatment of Physician's Choice (TPC) in subjects with unresectable locally advanced, recurrent, or metastatic HR+/HER2- breast cancer who had failed at least one line of systemic chemotherapy.

• Study Type: Interventional
• Enrollment (Estimated): 376
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Yina Diao; Phone Number: 86-13402828610; Email: diaoyina@kelun.com

Study Locations

• China
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100021
      • Recruiting
      • Cancer Hospital Chinese Academy of Medical Science
      • Contact: BingHe Xu, PhD

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Males or females aged ≥ 18 to ≤ 75 years at the time of signing the ICF;
• Histologically and/or cytologically confirmed HR+/HER2- breast cancer based on pathology reports on recent biopsy specimens or other pathological samples;
• Patients who had failed at least one line of systemic chemotherapy in unresectable locally advanced, recurrent, or metastatic stage;
• Patients with at least one measurable lesion per RECIST 1.1 criteria; those with only skin or bone lesions cannot be included;
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0 to 1;
• Expected survival ≥ 12 weeks;
• Adequate organ and bone marrow function;
• Patients who are eligible for a chemotherapy regimen in the control group;
• Female patients of childbearing potential and male patients with partners of childbearing potential who use effective medical contraception from the time of signing the informed consent form until 6 months after the last dose;
• Patients who voluntarily participate in the study and sign the ICF, and able to comply with the visit and related procedures stipulated in the plan.

Exclusion Criteria:

• Patients with a history of central nervous system (CNS) metastases or current CNS metastases；
• Patients with other malignancies (except cured basal or squamous cell skin cancer or carcinoma in situ of the cervix) within 3 years prior to the first dose;
• Patients with any cardio cerebral Vascular disease or cardio cerebral vascular risk factors may affect investigational treatment;
• Uncontrollable systemic diseases assessed by the investigator;
• History of (noninfectious) interstitial lung disease (ILD)/noninfectious neumonitis requiring steroid therapy and current ILD/noninfectious pneumonitis, or ILD/noninfectious pneumonitis at screening that cannot be excluded by imaging;
• Clinically serious lung injuries caused by lung diseases;
• Patients with active chronic Inflammatory bowel disease, gastrointestinal obstruction, severe ulcer, gastrointestinal perforation, abdominal abscess or acute gastrointestinal bleeding;
• Toxicities from prior anti-tumor therapy not recovering to ≤ Grade 1;
• Active hepatitis B or hepatitis C;
• Human immunodeficiency virus (HIV) antibody test positive or a history of acquired immunodeficiency syndrome (AIDS), known active syphilis infection;
• Known allergy or hypersensitivity to SKB264, or the excipients of SKB264;
• Prior TROP2 targeted therapy, prior topoisomerase I inhibitor therapy, including antibody-drugconjugate(ADC) therapy;
• Patients who received major surgeries 4 weeks prior to the first dose of study treatment or planned to receive major surgeries during the study ;
• Patients with concomitant infections requiring systemic antibiotic therapy within 2 week prior to the first dose of study treatment;
• Patients who have received live vaccines within 30 days prior to the first dose, or are scheduled to receive live vaccines during the study;
• Pregnant or lactating women.

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: SKB264 for injection	Drug: SKB264; IV infusion on day 1 and Day 15 of each 28 day cycle
Active Comparator: Treatment of Physician's Choice; Eribulin, capecitabine, gemcitabine or vinorelbine will be administered and managed according to the investigator's clinical judgment, guided by clinical practice.	Drug: Eribulin; 1.4 mg/m2, IV infusion on day 1 and Day 8 of each 21 day cycle; Drug: Capecitabine; 1000-1250 mg/m2, po, bid, from day 1 to Day 15 of each 21 day cycle; Drug: Gemcitabine; 1000 mg/m2, IV infusion on day 1 and Day 8 of each 21day cycle; Drug: Vinorelbine; 25 mg/m2, IV infusion on day 1 and Day 8 of each 21 day cycle

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-free survival (PFS) assessed by BIRC per RECIST 1.1.	PFS, defined as the time from randomization to PD or death, whichever occurs first.	up to 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
AEs and SAEs	Incidence and severity of AEs and SAEs (per CTCAE 5.0), and clinically significant abnormal laboratory findings	AEs should be observed and recorded from signing the ICF until 30 days after the last dose. AEs occurring 30 days after the last dose are not required to be actively collected by the investigator.
Overall Survival (OS)	OS, defined as the time from randomization to death	up to 24 months
Progression-free survival (PFS) assessed by the investigators per RECIST V 1.1	PFS, defined as the time from randomization to PD or death, whichever occurs first.	up to 24 months
Objective Response Rate (ORR)	The percentage of patients with CR and PR assessed by BIRC and investigators per RECIST v 1.1	up to 24 months
Disease Control Rate (DCR)	The percentage of patients who have achieved CR，PR and SD assessed by BIRC and investigators per RECIST v 1.1	up to 24 months
Duration of Response (DoR)	From the date that response criteria are first met to the first occurrence of PD as determined by BIRC and investigators per RECIST v1.1 or death from any cause, whichever occurs first	up to 24 months
Quality of life of patients evaluated using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) scale	To assess the impact of SKB264 on disease related symptoms and health related quality of life (HRQoL) in this patient population	Up to 2 years

Collaborators and Investigators

• Sponsor: Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): October 31, 2023
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: October 7, 2023
• First Submitted That Met QC Criteria: October 7, 2023
• First Posted (Actual): October 13, 2023

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Nucleic Acids, Nucleotides, and Nucleosides; Alkaloids; Indoles; Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Nucleosides; Uracil; Pyrimidinones; Vinca Alkaloids; Secologanin Tryptamine Alkaloids; Indole Alkaloids; Indolizidines; Indolizines; Deoxyribonucleosides; Fluorouracil; Capecitabine; Vinorelbine; Gemcitabine; eribulin
• Other Study ID Numbers: SKB264-Ⅲ-10

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No