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A Study of A166 Versus Trastuzumab Emtansine (T-DM1) in Patients With HER2-Positive Unresectable or Metastatic Breast Cancer Previously Treated With Trastuzumab and Taxane Therapy

A Phase III,Multicenter,Randomized,Open-Label,Active-Controlled Trial of A166 Versus Trastuzumab Emtansine (T-DM1) in Patients With HER2-Positive Unresectable or Metastatic Breast Cancer Previously Treated With Trastuzumab and Taxane Therapy

Status
Active, not recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06968585
Acronym
A166
Enrollment
365
Registered
2025-05-13
Start date
2023-07-18
Completion date
2028-03-31
Last updated
2026-05-08

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

Conditions

HER2-positive Breast Cancer

Brief summary

Evaluation of the efficacy of A166 versus trastuzumab emtansine (T-DM1) in Patients with HER2-Positive unresectable or metastatic breast cancer previously treated with trastuzumab and taxane therapy

Detailed description

This study will evaluate the efficacy of A166 versus trastuzumab emtansine (T-DM1) in patients with HER2-positive unresectable or metastatic breast cancer previously treated with trastuzumab and taxane therapy To further evaluate the efficacy of A166 versus T-DM1 in patients with HER2-positive unresectable or metastatic breast cancer, based on effectiveness endpoints including: Overall survival (OS) Progression-free survival (PFS) as assessed by investigators Objective response rate (ORR), disease control rate (DCR), duration of response (DOR), and clinical benefit rate (CBR) assessed by both blinded independent central review (BICR) and investigators. To assess the safety profile of A166 for injection in patients with HER2-positive unresectable or metastatic breast cancer. To evaluate the immunogenicity of A166 for injection in patients with HER2-positive unresectable or metastatic breast cancer. To characterize the pharmacokinetic (PK) profile of A166 for injection in patients with HER2-positive unresectable or metastatic breast cancer.

Interventions

DRUGA166

intravenous(IV) infusion (Q3W)

DRUGT-DM1

intravenous(IV) infusion (Q3W)

Sponsors

Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd.
Lead SponsorINDUSTRY

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

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

Inclusion criteria

1. Male or female patient ≥ 18 years and ≤ 75 years when signing the informed consent form. 2. Breast cancer patients by histopathology and/or cytology documented. 3. Disease progression after receiving a trastuzumab-based regimen (or a commercially available trastuzumab biosimilar or inetetamab) in the advanced or metastatic setting, or disease progression/recurrence within 12 months during or after (neo)adjuvant therapy (with a trastuzumab-based regimen or commercially available trastuzumab biosimilar). 4. Have previously received taxanes. 5. Patients must have experienced disease progression or intolerance during or after the most recent treatment prior to randomization. 6. At least one measurable lesion according to RECIST 1.1 criteria

Exclusion criteria

1. Previous treatment with A166 or any HER2-targeted antibody-drug conjugate (ADC) with a microtubule inhibitor payload. 2. Known history of severe hypersensitivity to other monoclonal antibodies, or allergy to A166 , T-DM1 (trastuzumab emtansine) or their components. 3. Permanent discontinuation of trastuzumab or its biosimilars due to any toxicity in prior treatments. 4. Presence of severe corneal epithelial disease at baseline; or inability to perform daily activities without contact lenses. 5. Presence of spinal cord compression or clinically active central nervous system (CNS) metastases. 6. Other conditions considered by the investigator to make the patient unsuitable for participation in the study

Design outcomes

Primary

MeasureTime frameDescription
Progression-free survival (PFS)Randomization up to approximately 39 monthsPFS as assessed by BICR according to RECIST v 1.1

Secondary

MeasureTime frameDescription
Overall survival (OS)Randomization up to approximately 48 monthsOS, 1-year survival rate, 2-year survival rate, and 3-year survival rate.
Objective response rate(ORR)Randomization up to approximately 39 monthsORR is defined as the percentage of patients who achieve complete response(CR) or partial response (PR), as assessed by BICR/investigator per RECIST 1.1
Disease control rate(DCR)Randomization up to approximately 39 monthsDCR is defined as the percentage of patients who achieve CR, PR or stable disease (SD), as assessed by BICR/investigator per RECIST 1.1
Duration of response(DOR)Randomization up to approximately 39 monthsDoR is defined as the time from the date of first documented CR or PR until date of documented disease progression per RECIST 1.1, as assessed by BICR/investigator or death due to any cause, whichever occurs first.

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 13, 2026