A Trial Comparing GQ1005 and T-DM1 in Patients With HER2-Positive Unresectable or Metastatic Breast Cancer

A Phase III, Multicenter, Open-label, Randomized Controlled Study Comparing GQ1005 and Trastuzumab Emtansine (T-DM1) in Patients With HER2-Positive Unresectable or Metastatic Breast Cancer Previously Treated With Trastuzumab and a Taxane

This study is designed to compare efficacy and safety of GQ1005 versus T-DM1 in HER2-positive, unresectable and/or metastatic breast cancer patients previously treated with trastuzumab and taxane.

Study Overview

• Status: Recruiting
• Conditions: HER2-positive Breast Cancer
• Intervention / Treatment: Drug: T-DM1; Drug: GQ1005

Detailed Description

This is a phase III, multicenter, open-label, randomized controlled study comparing GQ1005 with Trastuzumab Emtansine (T-DM1) in patients with HER2-positive unresectable or metastatic breast cancer previously treated with trastuzumab and taxane. Approximately 228 patients with unresectable or metastatic HER2-positive breast cancer will be randomized 1:1 to receive GQ1005 or T-DM1, respectively.

• Study Type: Interventional
• Enrollment (Estimated): 228
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Zhenxing Yang; Phone Number: +86 13801896162; Email: yangzx@genequantum.com

Study Locations

• China
  • Anhui
    • Bengbu, Anhui, China, 233004
      • Recruiting
      • The First Affiliated Hospital of Bengbu Medical University
      • Contact: Zhang Mingliang
    • Fuyang, Anhui, China, 236000
      • Recruiting
      • The Affiliated Fuyang Hospital of Anhui Medical University
      • Contact: Yingying Du
    • Hefei, Anhui, China, 230031
      • Recruiting
      • Anhui Cancer Hospital
      • Contact: Yueyin Pan
    • Hefei, Anhui, China, 230001
      • Recruiting
      • The First Affiliated Hospital of Anhui Medical University
      • Contact: Xinghua Han
  • Beijing Municipality
    • Beijing, Beijing Municipality, China, 100071
      • Recruiting
      • The Fifth Medical Center of the Chinese People's Liberation Army General Hospital
      • Contact: Zefei Jiang
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China, 400030
      • Recruiting
      • Chongqing University Cancer Hospital
      • Contact: Xianjun Tang
  • Fujian
    • Fuzhou, Fujian, China, 350014
      • Recruiting
      • Fujian Cancer Hospital
      • Contact: Fan Wu
    • Quanzhou, Fujian, China, 362000
      • Recruiting
      • The Second Affiliated Hospital of Fujian Medical University
      • Contact: Jianqing Lin
  • Guangdong
    • Guangzhou, Guangdong, China, 510060
      • Recruiting
      • Sun Yat-sen University Cancer Center
      • Contact: Fei Xu
    • Guangzhou, Guangdong, China, 510120
      • Recruiting
      • Sun Yat-sen Memorial Hospital, Sun Yat-sen University
      • Contact: Ying Wang
      • Principal Investigator: Jianli Zhao
    • Meizhou, Guangdong, China, 514011
      • Recruiting
      • Meizhou People's Hospital
      • Contact: Jingna Wu
    • Shantou, Guangdong, China, 515031
      • Recruiting
      • Shantou Central Hospital
      • Contact: Zhiyong Wu
  • Guangxi
    • Nanning, Guangxi, China, 530021
      • Recruiting
      • Guangxi Medical University Cancer Hospital
      • Contact: Weimin Xie
  • Guizhou
    • Guiyang, Guizhou, China, 550002
      • Recruiting
      • Guizhou Provincial People's Hospital
      • Contact: Yong Li
    • Guiyang, Guizhou, China, 550004
      • Recruiting
      • Guizhou Medical University Cancer Hospital
      • Contact: Zhihong Wang
  • Hebei
    • Baoding, Hebei, China, 71000
      • Recruiting
      • The Affiliated Hospital of Hebei University
      • Contact: Hua Yang
    • Handan, Hebei, China, 56002
      • Recruiting
      • The Affiliated Hospital of Hebei University of Engineering
      • Contact: Jianjun Han
    • Shijiazhuang, Hebei, China, 50011
      • Recruiting
      • The Fourth Hospital of Hebei Medical University
      • Contact: Yunjiang Liu
    • Xingtai, Hebei, China, 54001
      • Recruiting
      • Xingtai People's Hospital
      • Contact: Li Wang
  • Heilongjiang
    • Harbin, Heilongjiang, China, 150081
      • Recruiting
      • Harbin Medical University Cancer Hospital
      • Contact: Qingyuan Zhang
  • Henan
    • Anyang, Henan, China, 455000
      • Recruiting
      • Anyang Cancer Hospital
      • Contact: Jing Sun
    • Luoyang, Henan, China, 471003
      • Recruiting
      • The First Affiliated Hospital of Henan University of Science and Technology
      • Contact: Xinshuai Wang
    • Luoyang, Henan, China, 471000
      • Recruiting
      • Luoyang Central Hospital
      • Contact: Mingli Ni
    • Xinxiang, Henan, China, 453003
      • Recruiting
      • The First Affiliated Hospital of Henan Medical University
      • Contact: Yinghua Ji
    • Xuchang, Henan, China, 461000
      • Recruiting
      • Xuchang Central Hospital
      • Contact: Ping Li
    • Zhengzhou, Henan, China, 450008
      • Recruiting
      • Henan Cancer Hospital
      • Contact: Min Yan
    • Zhengzhou, Henan, China, 450052
      • Recruiting
      • The First Affiliated Hospital of Zhengzhou University
      • Contact: Fang Wang
  • Hubei
    • Wuhan, Hubei, China, 430071
      • Recruiting
      • Zhongnan Hospital of Wuhan University
      • Contact: Haijun Yu
    • Wuhan, Hubei, China, 430030
      • Recruiting
      • Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
      • Contact: Huihua Xiong
    • Wuhan, Hubei, China, 430060
      • Recruiting
      • Renmin Hospital of Wuhan University
      • Contact: Feng Yao
    • Wuhan, Hubei, China, 430079
      • Recruiting
      • Hubei Cancer Hospital
      • Contact: Xinhong Wu
    • Wuhan, Hubei, China, 430022
      • Recruiting
      • Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
      • Contact: Yanxia Zhao
  • Hunan
    • Changsha, Hunan, China, 410013
      • Recruiting
      • Hunan Cancer Hospital
      • Contact: Quchang Ouyang
    • Yongzhou, Hunan, China, 425000
      • Recruiting
      • Yongzhou Central Hospital
      • Contact: Sijuan Du
  • Jiangsu
    • Xuzhou, Jiangsu, China, 221009
      • Recruiting
      • Xuzhou Central Hospital
      • Contact: Yanhua Liu
  • Jiangxi
    • Ganzhou, Jiangxi, China, 341000
      • Recruiting
      • Ganzhou Cancer Hospital
      • Contact: Yongqiang Ye
    • Nanchang, Jiangxi, China, 330006
      • Recruiting
      • Nanchang People's Hospital
      • Contact: Yili Wang
  • Jilin
    • Changchun, Jilin, China, 130021
      • Recruiting
      • The First Hospital of Jilin University
      • Contact: Jiuwei Cui
  • Liaoning
    • Dalian, Liaoning, China, 116023
      • Recruiting
      • The Second Affiliated Hospital of Dalian Medical University
      • Contact: Man Li
    • Jinzhou, Liaoning, China, 121001
      • Recruiting
      • The First Affiliated Hospital of Jinzhou Medical University
      • Contact: Zhenhua Zhai
    • Shenyang, Liaoning, China, 110001
      • Recruiting
      • The First Affiliated Hospital of China Medical University
      • Contact: Yuee Teng
    • Shenyang, Liaoning, China, 110042
      • Recruiting
      • Liaoning Cancer Hospital
      • Contact: Tao Sun
  • Shaanxi
    • Xi'an, Shaanxi, China, 710061
      • Recruiting
      • The First Affiliated Hospital of Xi'an Jiaotong University
      • Contact: Jin Yang
    • Xi'an, Shaanxi, China, 710004
      • Recruiting
      • The Second Affiliated Hospital of Xi'an Jiaotong University
      • Contact: Shuqun Zhang
  • Shandong
    • Jinan, Shandong, China, 250117
      • Recruiting
      • Shandong Cancer Hospital
      • Contact: ZhiyongYu
    • Linqing, Shandong, China, 252601
      • Recruiting
      • The Second People's Hospital of Liaocheng City
      • Contact: Yanjun Wang
    • Linyi, Shandong, China, 276001
      • Recruiting
      • Linyi Cancer Hospital
      • Contact: Jingfen Wang
    • Linyi, Shandong, China, 276003
      • Recruiting
      • Linyi Central Hospital
      • Contact: Yuzhou Li
    • Qingdao, Shandong, China, 266003
      • Recruiting
      • The Affiliated Hospital of Qingdao University
      • Contact: WenfengLi
    • Qingzhou, Shandong, China, 262500
      • Recruiting
      • Yidu Central Hospital of Weifang City
      • Contact: Peng Wang
    • Weifang, Shandong, China, 261041
      • Recruiting
      • Weifang People's Hospital
      • Contact: Wenhui Wang
    • Yantai, Shandong, China, 264000
      • Recruiting
      • Yantai YuHuangDing Hospital
      • Contact: Ping Sun
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200032
      • Recruiting
      • Fudan University Shanghai Cancer Center
      • Contact: Biyun Wang
    • Shanghai, Shanghai Municipality, China, 200127
      • Recruiting
      • Renji Hospital, School of Medicine, Shanghai Jiao Tong University
      • Contact: Jinsong Lu
    • Shanghai, Shanghai Municipality, China, 201103
      • Recruiting
      • Shanghai Gaobo Cancer Hospital
      • Contact: Shuang Li
  • Shanxi
    • Taiyuan, Shanxi, China, 30013
      • Recruiting
      • Shanxi Cancer Hospital
      • Contact: Guohui Han
  • Sichuan
    • Chengdu, Sichuan, China, 610041
      • Recruiting
      • West China Hospital of Sichuan University
      • Contact: Ting Luo
    • Chengdu, Sichuan, China, 610031
      • Recruiting
      • The Third People's Hospital of Chengdu City
      • Contact: Zhume Luo
    • Deyang, Sichuan, China, 618000
      • Recruiting
      • Deyang People's Hospital
      • Contact: Xinjian Jia
    • Neijiang, Sichuan, China, 641003
      • Recruiting
      • The Second People's Hospital of Neijiang City
      • Contact: Xujuan Wang
    • Suining, Sichuan, China, 629000
      • Recruiting
      • Suining Central Hospital
      • Contact: Hongwei Yang
  • Tianjin Municipality
    • Tianjin, Tianjin Municipality, China, 300060
      • Recruiting
      • Tianjin Cancer Hospital
      • Contact: Yehui Shi
  • Yunnan
    • Kunming, Yunnan, China, 650118
      • Recruiting
      • Yunnan Cancer Hospital
      • Contact: Wenlin Chen
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310022
      • Recruiting
      • Zhejiang Cancer Hospital
      • Contact: Yabing Zheng
    • Hangzhou, Zhejiang, China, 310009
      • Recruiting
      • The Second Affiliated Hospital of Zhejiang University School of Medicine
      • Contact: Fuming Qiu
    • Hangzhou, Zhejiang, China, 310016
      • Recruiting
      • Sir Run Run Shaw Hospital, Zhejiang University School of Medicine
      • Contact: Xian Wang
    • Hangzhou, Zhejiang, China, 310006
      • Recruiting
      • The First People's Hospital of Hangzhou City
      • Contact: Jian Liu
    • Hangzhou, Zhejiang, China, 310006
      • Recruiting
      • Women's Hospital, Zhejiang University School of Medicine
      • Contact: Jingpei Long
    • Hangzhou, Zhejiang, China, 311200
      • Recruiting
      • The First People's Hospital of Xiaoshan District, Hangzhou City
      • Contact: Zhenyu Wang
    • Ningbo, Zhejiang, China, 315040
      • Recruiting
      • The Affiliated People's Hospital of Ningbo University
      • Contact: Zhengyang Xu

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male or female adults ≥ 18 years at the time of voluntary signing of informed consent.
• Pathologically confirmed unresectable or metastatic HER2 positive breast cancer previously treated with trastuzumab and taxane
• Eastern Cooperative Oncology Group (ECOG) performance status score is 0 or 1.
• Presence of at least one measurable lesion according to RECIST v1.1
• Expected survival time ≥ 12 weeks.
• Patients must give informed consent to this study and voluntarily sign written informed consent form prior to the study NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Exclusion Criteria:

• Prior anti-HER2 ADC therapy.
• Previous history of interstitial lung disease/noninfectious pneumonitis/radiation pneumonitis requiring steroid therapy.
• Known serious hypersensitivity to the active ingredients of the study drug, inactive ingredients in the formulation, or other antibody drugs.
• Multiple primary malignancies within 3 years, except for adequately resected non-melanoma skin cancer, curatively treated in situ tumor, or contralateral breast cancer
• Uncontrolled infection requiring intravenous antibiotics, antiviral or antifungal agents, autoimmune disease requiring treatment, uncontrolled diabetes, hypertension, or other systemic disease that makes compliance with study procedures difficult
• Unrecovered toxicity from prior anticancer therapy, defined as toxicity (except for alopecia) not recovered to ≤Grade 1 (NCI-CTCAE v5.0) or baseline.

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: GQ1005; GQ1005 will be administered intravenously every 21 days.	Drug: GQ1005; Administered I.V.
Experimental: T-DM1; T-DM1 will be administered intravenously every 21 days.	Drug: T-DM1; Administered I.V.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Progression Free Survival (PFS) by Blinded Independent Central Review (BICR) assessment per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)	Up to approximately 24 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival (OS)		Up to approximately 24 months
Progression Free Survival (PFS) by Investigator assessment per RECIST 1.1		Up to approximately 24 months
Objective response rate (ORR) by BICR and investigator assessment per RECIST 1.1		Up to approximately 24 months
Duration of response (DoR) by BICR and investigator assessment per RECIST 1.1		Up to approximately 24 months
Disease Control Rate (DCR) by BICR and investigator assessment per RECIST 1.1		Up to approximately 24 months
Adverse events：Number and percentage of patients who report serious adverse events (SAEs), treatment-emergent adverse events (TEAEs), TEAEs leading to study drug discontinuation, adverse events of special interest (AESIs) (graded according to the Nationa		Up to approximately 24 months
PK parameters：Plasma concentrations of GQ1005 ADC, total anti-HER2 antibody and free toxin DXd at each time point		Up to approximately 24 months
Anti-drug antibodies (ADA)：Number and percentage of patients who develop anti-drug antibody (ADA).		Up to approximately 24 months
Quality of Life Assessment：Change in Health-Related Quality of Life Assessed by EQ-5D-5L	Change from baseline in EQ-5D-5L health state utility index score and Visual Analogue Scale (VAS) score. VAS score range from 0-100, higher scores indicate better health status.	Up to approximately 24 months
Quality of Life Assessment：Change in Health-Related Quality of Life Assessed by European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) - C30	Change from baseline in the functioning/symptom/global quality of life (QoL) subscales of EORTC QLQ-C30. Scale scores range from 0-100. For functioning and global QoL scales, higher scores indicate better functioning or global health status. For symptom scales, higher scores indicate greater symptom burden.	Up to approximately 24 months
Quality of Life Assessment：Change in Health-Related Quality of Life Assessed by EORTC QLQ-BR45	Change from baseline in the functioning/symptom subscales of EORTC QLQ-BR45. Scale scores range from 0-100. For functioning scales, higher scores indicate better functioning. For symptom scales, higher scores indicate greater symptom burden.	Up to approximately 24 months

Collaborators and Investigators

• Sponsor: GeneQuantum Healthcare (Suzhou) Co., Ltd.
• Investigators: Principal Investigator: Zefei Jiang, M.D., The Fifth Medical Center of the Chinese People's Liberation Army General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2025
• Primary Completion (Estimated): January 9, 2027
• Study Completion (Estimated): January 9, 2028

Study Registration Dates

• First Submitted: June 17, 2026
• First Submitted That Met QC Criteria: June 24, 2026
• First Posted (Actual): June 29, 2026

Study Record Updates

• Last Update Posted (Actual): June 29, 2026
• Last Update Submitted That Met QC Criteria: June 24, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: GQ1005-301

Drug and device information, study documents

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