Breast Cancer
Conditions
Keywords
HER2-positive, Neoadjuvant therapy, Antibody-drug conjugate, SHR-A1811, HER2-targeted therapy
Brief summary
This is a multicenter, two-arm, exploratory clinical study designed to evaluate the efficacy and safety of a response-guided neoadjuvant treatment strategy in patients with HER2-positive early or locally advanced breast cancer. Breast cancer is the most common malignancy in women worldwide, and HER2-positive disease accounts for approximately 15-20% of cases and is associated with aggressive tumor biology and a higher risk of recurrence. The introduction of HER2-targeted therapies, including trastuzumab and pertuzumab, has significantly improved patient outcomes. However, a proportion of patients exhibit suboptimal response to standard neoadjuvant therapy, highlighting the need for more effective treatment strategies. In this study, approximately 100 eligible patients will be enrolled. All patients will initially receive 2 cycles of standard neoadjuvant therapy with trastuzumab, pertuzumab, and chemotherapy (THP or TCbHP). Tumor response will be assessed according to RECIST version 1.1 criteria. Patients with tumor reduction greater than 40% will continue the same regimen for an additional 4 cycles. Patients with tumor reduction of 40% or less will switch to an alternative regimen consisting of SHR-A1811, a novel HER2-targeted antibody-drug conjugate, in combination with pertuzumab for 4 cycles. SHR-A1811 is an investigational HER2-targeted antibody-drug conjugate designed to deliver a cytotoxic payload directly to tumor cells, potentially overcoming resistance to prior HER2-targeted therapies. Emerging clinical data have demonstrated promising anti-tumor activity and manageable safety in HER2-positive breast cancer. Clinical data, including baseline characteristics, imaging findings, and pathological markers such as Ki-67, will be collected throughout the study. Efficacy will be evaluated based on imaging assessments according to RECIST 1.1 criteria and pathological response at surgery, while safety will be monitored during treatment. The primary objective of this study is to explore whether switching to SHR-A1811 in combination with pertuzumab in patients with suboptimal early response can improve pathological complete response (pCR) rates. Secondary objectives include evaluation of safety and tolerability of the treatment strategies. This study aims to provide evidence for an individualized, response-adapted neoadjuvant treatment approach in HER2-positive breast cancer, and to optimize treatment outcomes for patients with inadequate response to standard therapy.
Detailed description
HER2-positive breast cancer is driven by overexpression or amplification of the HER2 receptor, leading to activation of downstream signaling pathways such as MAPK and PI3K/AKT that promote tumor growth and survival. Although dual HER2 blockade with trastuzumab and pertuzumab in combination with chemotherapy has become a standard neoadjuvant treatment, a subset of patients exhibit insufficient tumor response, indicating biological heterogeneity and potential resistance to therapy. Pathological complete response (pCR) after neoadjuvant treatment is associated with improved long-term outcomes in HER2-positive breast cancer. Therefore, early identification of patients with suboptimal response and timely treatment modification may represent an effective strategy to improve prognosis. Antibody-drug conjugates (ADCs) are designed to selectively deliver cytotoxic agents to tumor cells through antigen-specific targeting. SHR-A1811 is an investigational HER2-directed ADC composed of a humanized anti-HER2 monoclonal antibody linked to a topoisomerase I inhibitor payload via a cleavable linker. Preclinical data have demonstrated potent anti-tumor activity in HER2-expressing models, including those with reduced sensitivity to prior HER2-targeted therapies. Emerging clinical evidence supports the antitumor activity and manageable safety profile of SHR-A1811 in HER2-positive breast cancer. Its mechanism of action suggests potential benefit in patients with inadequate response to standard HER2-targeted neoadjuvant regimens. This study is designed to investigate a response-adapted treatment strategy, in which early tumor response is used to guide subsequent therapy selection. By incorporating an alternative HER2-targeted approach for patients with suboptimal response, this study aims to explore strategies to improve treatment efficacy while maintaining an acceptable safety profile. The results of this study are expected to provide evidence to support individualized neoadjuvant treatment strategies for patients with HER2-positive breast cancer.
Interventions
DRUGSHR-A1811
SHR-A1811 is a HER2-targeted antibody-drug conjugate administered intravenously in combination with pertuzumab as neoadjuvant therapy.
DRUGPertuzumab
Pertuzumab is a monoclonal antibody targeting HER2, administered intravenously as part of dual HER2 blockade.
DRUGtrastuzumab
Trastuzumab is a HER2-targeted monoclonal antibody administered intravenously as part of standard neoadjuvant therapy.
DRUGChemotherapy
Chemotherapy includes taxane-based regimens with or without carboplatin (THP or TCbHP) administered according to institutional standards.
Sponsors
Hebei Medical University Fourth Hospital
Jiangsu Hengrui Pharmaceutical Co., Ltd.
Study design
Allocation
NON_RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
All enrolled patients will receive 2 initial cycles of standard neoadjuvant therapy with trastuzumab, pertuzumab, and chemotherapy (THP or TCbHP). Tumor response will then be assessed according to RECIST version 1.1 criteria. Based on early response evaluation, patients will be assigned to subsequent treatment strategies. Patients demonstrating a tumor reduction greater than 40% will continue the same neoadjuvant regimen for an additional 4 cycles. Patients with a tumor reduction of 40% or less will switch to an alternative treatment consisting of SHR-A1811 in combination with pertuzumab for 4 cycles. This response-adapted, sequential assignment design allows treatment modification according to early tumor response, with the aim of optimizing therapeutic outcomes.
Eligibility
Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No
Inclusion criteria
Participants must meet all of the following criteria: 1. Age ≥18 and ≤70 years. 2. Eastern Cooperative Oncology Group (ECOG) performance status of 0-1. 3. At least one measurable lesion according to RECIST version 1.1. 4. Histologically confirmed invasive breast cancer with clinical stage: Stage II (T2N0-1M0 or T3N0M0), or Stage III (T2N2-3M0, T3N1-3M0, or T4N0-3M0). 5.HER2-positive invasive breast cancer confirmed by histopathology, defined as: HER2 immunohistochemistry (IHC) 3+, or HER2 IHC 2+ with fluorescence in situ hybridization (FISH) positivity, as determined by the pathology department of the participating center. 6.Adequate organ function, defined as: 1. Hematologic function (no blood transfusion, blood products, granulocyte colony-stimulating factor \[G-CSF\], or other hematopoietic growth factors within 14 days prior to testing): Hemoglobin (Hb) ≥100 g/L; Absolute neutrophil count (ANC) ≥1.5 × 10⁹/L; Platelet count (PLT) ≥100 × 10⁹/L. 2. Biochemical function: Total bilirubin (TBIL) ≤1 × upper limit of normal (ULN); Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤1.5 × ULN; Alkaline phosphatase (ALP) ≤2.5 × ULN; Blood urea nitrogen (BUN) and serum creatinine (Cr) ≤1.5 × ULN. 3. Cardiac function: Left ventricular ejection fraction (LVEF) ≥55% by echocardiography; QT interval corrected by Fridericia's formula (QTcF) ≤450 ms. 7.Women of childbearing potential must have a negative serum pregnancy test within 14 days prior to enrollment and agree to use effective contraception during the study and for at least 8 weeks after the last dose of study treatment. 8.Willingness to participate in the study, provide written informed consent, and comply with study procedures and follow-up.
Exclusion criteria
Participants meeting any of the following criteria will be excluded: 1. Prior receipt of any anti-tumor therapy not specified in the study protocol, including but not limited to chemotherapy, radiotherapy, targeted therapy, or endocrine therapy for the current breast cancer. 2. Concurrent receipt of any other anti-tumor therapy during the study. Bilateral breast cancer, inflammatory breast cancer, or occult breast cancer. Stage IV (metastatic) breast cancer. 3. History of other malignancies within the past 5 years, except for adequately treated carcinoma in situ of the cervix. 4. Severe dysfunction of major organs, including but not limited to cardiac, hepatic, or renal insufficiency. 5. Participation in another interventional clinical trial within 4 weeks prior to enrollment. 6. Known hypersensitivity to any component of the study drugs; history of immunodeficiency, including positive human immunodeficiency virus (HIV) test, active hepatitis C virus (HCV) infection, active hepatitis B infection, congenital or acquired immunodeficiency disorders, or history of organ transplantation. History of significant cardiac disease, including but not limited to: Clinically significant arrhythmia requiring treatment; Myocardial infarction; Heart failure; 7. Any other cardiac condition that, in the investigator's judgment, makes the participant unsuitable for the study. 8. Pregnant or breastfeeding women; women of childbearing potential with a positive pregnancy test at baseline or unwilling to use effective contraception throughout the study period. 9. Any serious concomitant disease that, in the investigator's judgment, may compromise patient safety or interfere with study participation, including but not limited to uncontrolled hypertension, severe diabetes, or active infection. History of neurological or psychiatric disorders, including epilepsy or dementia. 10. Any other condition that, in the investigator's judgment, makes the participant unsuitable for participation in this study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total Pathological Complete Response (tpCR) | At surgery (approximately 18 weeks after initiation of treatment) | Number of participants achieving total pathological complete response, defined as no residual invasive cancer in both breast and axillary lymph nodes (ypT0/is ypN0) at the time of surgery following completion of neoadjuvant therapy.Metric：Proportion of participants (%) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Objective Response Rate (ORR) per RECIST v1.1 | From baseline to surgery (approximately 18 weeks) | Proportion of participants with a best overall response of complete response (CR) or partial response (PR) according to RECIST version 1.1. |
| Event-Free Survival (EFS) | From first dose up to 3 years | Time from treatment initiation to the occurrence of disease progression, local or distant recurrence, or death from any cause.Metric：Time-to-event (months). |
| Breast Conservation Rate | At surgery (approximately 18 weeks) | Proportion of participants who undergo breast-conserving surgery after completion of neoadjuvant therapy. |
| Number of Participants With Treatment-Related Adverse Events (TRAEs) | From first dose to 30 days after last dose | Number of participants experiencing treatment-related adverse events, assessed according to CTCAE version 5.0. |
| Number of Participants With Grade ≥3 Adverse Events | From first dose to 30 days after last dose | Number of participants experiencing Grade 3 or higher adverse events according to CTCAE version 5.0. |
| Number of Participants With Serious Adverse Events (SAEs) | From first dose to 30 days after last dose | Number of participants experiencing serious adverse events as defined by ICH guidelines. |
Countries
China
Contacts
CONTACTLi Ma, MD
Outcome results
None listed