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RecruitingNCT07757230Updated Oct 14, 2026

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 2 interventional study of SSGJ-612 (HER2-targeted antibody) and HER2-targeted ADC in Metastatic Breast Cancer, sponsored by Shenyang Sunshine Pharmaceutical Co., LTD.. Recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-14.

Sponsored by Shenyang Sunshine Pharmaceutical Co., LTD. (part of 3SBio Inc.) · Phase 2, Interventional, and Treatment

From the registry’s dates

  • Started Sep 2026; still recruiting 1 month later.
Updated Oct 14, 2026Now RecruitingSite recruiting status changedGo to Updates ↓
Phase
Phase 2
Study type
Interventional
Enrollment
87
Allocation
Non-randomized
Ages
18 Years to 75 Years
Sex
All
01

Study 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.

Read the 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.

02

Conditions studied

  • Metastatic Breast Cancer

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03

In context

Breast Neoplasms

14,825 studies on the registry are indexed under Breast Neoplasms; 3,319 are open to participants now.

This study's planned enrollment of 87 is above the median of 72 across 10,896 interventional studies indexed under Breast Neoplasms.

Browse Breast Neoplasms studies →

Lead sponsor

Shenyang Sunshine Pharmaceutical Co., LTD. is the lead sponsor of 40 studies on the registry; 23 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 75 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Voluntary participation in this study, signed 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. tumor;
    2. Tumor samples tested by central laboratory confirmed as -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 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 v1.1 criteria.

Exclusion criteria

Exclusion Criteria:

  • Uncontrolled or severe cardiovascular disease.
  • History of interstitial lung disease (ILD)/pneumonia requiring therapy (non-infectious), or current ILD/pneumonia, or suspected ILD/pneumonia not excluded by screening imaging.
  • Presence of pulmonary-specific, comorbid conditions.
  • Presence of spinal cord compression, or clinically active central nervous system .
  • Female patients who are pregnant, breastfeeding, or planning pregnancy.
  • Patients who received 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.
Terms in these criteria, in plain language(8)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Metastases

Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.

HER2

HER2 is a protein, made from the ERBB2 gene, that drives the growth of some cancers. A study may look for a level of the protein, extra copies of the gene, or a particular change in it.

In breast cancer, protein tests are read as HER2-positive, HER2-low or HER2-negative; other cancers use their own rules. Check which test result the study requires.

Line of therapy

A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.

“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.

RECIST

The standard rules for measuring tumours on CT or MRI scans, to tell whether a cancer is shrinking, stable or growing during treatment.

“Measurable disease per RECIST 1.1” usually means at least one tumour 10 mm or more at its longest on a CT scan, or a lymph node 15 mm or more across its short axis.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 2
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
87 participants (estimated)

Study arms

  • Experimental
    Part 1

    Breast cancer patients who have received at least one line of chemotherapy for metastatic disease

    Drug: SSGJ-612 (HER2-targeted antibody) · Drug: HER2-targeted ADC

  • Experimental
    Part 2

    Breast cancer patients who have not received any chemotherapy for metastatic disease

    Drug: SSGJ-612 (HER2-targeted antibody) · Drug: HER2-targeted ADC

Interventions

  • DrugSSGJ-612 (HER2-targeted antibody)

    Intravenous injection

  • DrugHER2-targeted ADC

    Intravenous injection

06

What researchers measure

Primary outcomes

  1. Objective Response Rate (ORR)

    The primary efficacy end point

    Time frame: 2 years

Secondary outcomes

  1. Incidence and Severity of Adverse Events (AEs)

    The secondary safety end point

    Time frame: 2 years

  2. Progression-Free-Survival (PFS)

    The secondary efficacy end point

    Time frame: 2 years

07

Study locations

1 of 1 sites recruiting
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

1 registry update since Sep 25, 2026
Status
Not yet recruiting→Recruiting
changed Oct 14, 2026
Sites
Sun Yat-sen University Cancer Center is now Recruiting
Oct 14, 2026
Show all 1 update
  1. Oct 14, 2026
    Not yet recruiting→Recruiting
    Sun Yat-sen University Cancer Center is now Recruiting
    + 2 other changes: verification date and date precision

From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗

10

Registry details

Key details

Study ID
NCT07757230
Responsible party
Sponsor
First posted
Aug 11, 2026
Start date
Sep 21, 2026
Primary completion
Feb 2028 (estimated)
Completion
Jul 2029 (estimated)
Last update
Oct 14, 2026

Study contacts

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

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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