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A Phase II Study of SSGJ-612 Plus a HER2-Targeted ADC in HR-Positive, HER2-Low or HER2-Ultralow Expression Metastatic Breast Cancer

A Phase II Clinical Study of SSGJ-612 in Combination With a Human Epidermal Growth Factor Receptor 2 (HER2)-Targeted Antibody-Drug Conjugate (ADC) in Patients With Hormone Receptor (HR)-Positive, HER2-Low or HER2-Ultralow Expression Metastatic Breast Cancer

Status
Not yet recruiting
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07757230
Enrollment
87
Registered
2026-08-11
Start date
2026-09-01
Completion date
2029-07-01
Last updated
2026-08-11

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metastatic Breast Cancer

Brief summary

This study is a phase II clinical trial of SSGJ-612 combined with a human epidermal growth factor receptor 2 (HER2)-targeted antibody-drug conjugate (ADC) in patients with hormone receptor (HR)-positive, HER2-low or HER2-ultralow metastatic breast cancer.

Detailed description

The study is divided into two parts: Participants in Part 1: Breast cancer patients who have received at least one line of chemotherapy for metastatic disease; Participants in Part 2: Breast cancer patients who have not received any chemotherapy for metastatic disease.

Interventions

DRUGSSGJ-612 (HER2-targeted antibody)

Intravenous injection

DRUGHER2-targeted ADC

Intravenous injection

Sponsors

Shenyang Sunshine Pharmaceutical Co., LTD.
Lead SponsorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No

Inclusion criteria

* Voluntary participation in this study, signed informed consent form, good treatment compliance, and willingness to cooperate to complete all trial procedures. * Expected survival duration ≥ 3 months. * Histopathologically confirmed breast cancer meeting all of the following criteria simultaneously: 1. Metastatic tumor; 2. Tumor samples tested by central laboratory confirmed as HER2-low or HER2 ultra-low expression; 3. No prior test results reporting HER2 positivity; 4. Tumor sample testing confirms hormone receptor-positive (HR+) status. * Patients must satisfy either of the following conditions: 1. Disease progression within 6 months after initiation of first-line endocrine therapy combined with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors for metastatic disease; 2. Received at least 2 lines of prior endocrine therapy for metastatic disease, with disease progression post-treatment. * Participants in Part 1: Breast cancer patients who have received at least one line of chemotherapy for metastatic disease; Participants in Part 2: Breast cancer patients who have not received any chemotherapy for metastatic disease. * At least one repeatedly and accurately measurable tumor lesion as target lesion assessed per RECIST v1.1 criteria.

Exclusion criteria

* Uncontrolled or severe cardiovascular disease. * History of interstitial lung disease (ILD)/pneumonia requiring corticosteroid therapy (non-infectious), or current ILD/pneumonia, or suspected ILD/pneumonia not excluded by screening imaging. * Presence of pulmonary-specific, clinically significant comorbid conditions. * Presence of spinal cord compression, or clinically active central nervous system metastases. * Female patients who are pregnant, breastfeeding, or planning pregnancy. * Patients who received investigational drug therapy in another clinical trial within 30 days prior to first study drug administration, or who are concurrently enrolled in another clinical trial. Note: Exclusions include participation in observational (non-interventional) clinical trials, or being in the follow-up phase of an interventional clinical trial. * Presence of drug abuse, or other diseases (e.g., psychiatric disorders) that, in the investigator's judgment, may interfere with patient participation in the trial or affect the assessment of trial outcomes.

Design outcomes

Primary

MeasureTime frameDescription
Objective Response Rate (ORR)2 yearsThe primary efficacy end point

Secondary

MeasureTime frameDescription
Incidence and Severity of Adverse Events (AEs)2 yearsThe secondary safety end point
Progression-Free-Survival (PFS)2 yearsThe secondary efficacy end point

Countries

China

Contacts

CONTACTShusen Wang M.D.
wangshus@susucc.org.cn+86 139 2616 8469

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 12, 2026