Exploratory Study of SHR-A1811 Via Different Administration Routes in Patients

Exploratory Study of Efficacy and Safety of Different Administration Routes of SHR-A1811 in Patients With HER2-Positive Advanced Breast Cancer

An Exploratory Study on the Efficacy and Safety of Different Administration Routes of SHR-A1811 in the Treatment of HER2-Positive Advanced Breast Cancer

Study Overview

• Status: Not yet recruiting
• Conditions: Advanced Breast Cancer; HER2 + Breast Cancer; HER2positive
• Intervention / Treatment: Drug: SHR-A1811; Drug: SHR-A1811

• Study Type: Interventional
• Enrollment (Estimated): 60
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Tianjin, China, 300060
    • Tianjin Medical University Cancer Insititute and Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Aged ≥ 18 years old.
2. Pathologically confirmed HER2-positive advanced breast cancer. HER2 positivity is defined as IHC 3+ in >10% immunoreactive cells or HER2 gene amplification confirmed by in situ hybridization (ISH), which shall be verified by the pathology department of the participating center.
3. Patients with advanced breast cancer who have received no more than 2 lines of prior systemic therapies.
4. Expected survival time ≥ 4 months.
5. Have at least one measurable lesion per RECIST 1.1 criteria (helical CT scan lesion diameter ≥ 10 mm with slice thickness ≤ 5 mm).
6. Adequate major organ function without blood transfusion.
7. Voluntarily participate in the study, sign informed consent form, with good compliance and willingness to complete follow-up visits.

Exclusion Criteria:

1. Prior treatment with anti-HER2 antibody-drug conjugates (ADC).
2. Known leptomeningeal metastasis or active brain metastasis.
3. A history of other malignancies within the past 5 years, except for cured cervical carcinoma in situ, cutaneous basal cell carcinoma and squamous cell carcinoma. Malignancies cured solely by surgery more than 5 years prior to enrollment are allowed.
4. Major surgery or severe trauma within 4 weeks before enrollment, or planned major surgery during the study period.
5. Participation in other investigational new drug clinical trials within 4 weeks prior to enrollment.
6. Presence of hereditary bleeding tendency or coagulation disorders.
7. Uncontrolled hypertension with systolic blood pressure >140 mmHg or diastolic blood pressure >90 mmHg despite standard antihypertensive therapy.
8. A history of clinically significant pulmonary diseases, including but not limited to interstitial pneumonia, active pneumonia, pulmonary fibrosis and radiation pneumonitis (excluding asymptomatic post-radiation changes without treatment requirement).
9. A history of severe cardiac diseases or uncontrolled cardiac conditions, including NYHA class II or higher cardiac insufficiency, unstable angina, myocardial infarction within one year, and arrhythmias requiring clinical intervention.
10. Conditions affecting drug intake and absorption, such as dysphagia, chronic diarrhea and intestinal obstruction.
11. Known allergy to any component of the study drugs.
12. Uncontrolled pleural effusion or ascites that cannot be relieved by drainage or other clinical interventions.
13. Severe uncontrolled comorbidities, including immune deficiency disorders (e.g. HIV positivity, history of organ transplantation), active hepatitis B or hepatitis C, and severe ongoing infections requiring systemic anti-infective treatment.
14. Any other conditions considered inappropriate for study enrollment by the investigator.

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: Arm 1: Weekly administration group	Drug: SHR-A1811; SHR-A1811 administered weekly; Drug: SHR-A1811; SHR-A1811 administered every two weeks (q2w)
Experimental: Arm 2: Every-two-weeks (Q2W) administration group	Drug: SHR-A1811; SHR-A1811 administered weekly; Drug: SHR-A1811; SHR-A1811 administered every two weeks (q2w)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective Response Rate (ORR)	Defined as the proportion of patients who achieve confirmed complete response (CR) or partial response (PR) to the study treatment, assessed per RECIST 1.1 criteria.	From enrollment until disease progression or up to 2 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Progression-Free Survival (PFS)	Defined as the time from study enrollment to the first documentation of disease progression (per RECIST 1.1) or all-cause death, whichever occurs first.	From enrollment until disease progression or up to 2 years

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Overall Survival (OS)	Defined as the time from study enrollment to all-cause death.	From enrollment until all-cause death.
Safety and Tolerability	Number of participants with treatment-related adverse events as assessed by CTCAE v5.0	From first dose of study drug up to 30 days after last dose

Collaborators and Investigators

• Sponsor: Tianjin Medical University Cancer Institute and Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): June 30, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2029

Study Registration Dates

• First Submitted: April 20, 2026
• First Submitted That Met QC Criteria: April 27, 2026
• First Posted (Actual): May 1, 2026

Study Record Updates

• Last Update Posted (Actual): May 1, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms by Site; Neoplasms; Skin Diseases; Breast Diseases; Skin and Connective Tissue Diseases; Breast Neoplasms
• Other Study ID Numbers: MA-BC-II-145

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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