SSGJ-612 plus a HER2-targeted ADC in HR-positive, HER2-low metastatic breast cancer

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This is a Phase II clinical trial evaluating the combination of SSGJ-612 with a HER2-targeted antibody-drug conjugate in patients with HR-positive, HER2-low or HER2-ultralow metastatic breast cancer. The study is split into two parts: Part 1 includes patients who have received at least one line of chemotherapy for metastatic disease, while Part 2 includes those who have not yet received chemotherapy for metastatic disease. Eligible participants must have metastatic breast cancer with central lab-confirmed HER2-low/ultralow, HR-positive status, adequate organ function, and an expected survival of at least 3 months. The lead sponsor is Shenyang Sunshine Pharmaceutical Co., with Sun Yat-sen University Cancer Center as the participating site.

Why it matters

Who can join: the full rules

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.

Where it's running

• Sun Yat-sen University Cancer Center
  Guangzhou, Guangdong, China Recruiting

Study contacts

• Study coordinator: Shusen Wang M.D.
• Email: wangshus@susucc.org.cn
• Phone: +86 139 2616 8469

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How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.