A Study of A166 Versus Trastuzumab Emtansine (T-DM1) in P... | NCT06968585

Status Module

Record Verification Date

May 2026

Overall Recruitment Status or Expanded Access Status

Active, not recruiting

Last Known Status

Not provided

Delayed Posting

Not provided

Why Stopped

Not provided

Expanded Access Info

Start Date

Jul 18, 2023Actual

Primary Completion Date

Nov 30, 2026Estimated

Completion Date

Mar 31, 2028Estimated

First Submitted Date

Apr 26, 2025

First Submission Date that Met QC Criteria

May 5, 2025

First Posted Date

May 13, 2025Actual

Results Waived

Not provided

Results First Submitted Date

Not provided

Results First Submitted that Met QC Criteria

Not provided

Results First Posted Date

Not provided

Certification/Extension (aka Delayed Results) First Submitted Date

Not provided

Certification/Extension First Submitted that Passed QC Review

Not provided

Certification/Extension First Posted Date

Not provided

Last Update Submitted Date

May 5, 2026

Last Update Posted Date

May 8, 2026Actual

Oversight Module

Has Data Monitoring Committee (DMC)

Yes

Is FDA Regulated Drug

Is FDA Regulated Device

Is Unapproved Device

Not provided

Pediatric Postmarket Surveillance of a Device Product

Not provided

Product Exported from US

Not provided

FDAAA801 Violation

Not provided

Description Module

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.

Design Module

Study Type

Interventional

Number of References to an Expanded Access Study

Not provided

Expanded Access Types

Not provided

Patient Registry

Not provided

Target Follow-Up Duration

Not provided

Phases

Phase 3

Interventional Study Design

Allocation

Biospecimen

No data available

No data is available for this block.

Enrollment

365Actual

Arms/Interventions Module

Arm Groups

Label	Type	Description	Intervention Names
A166	Experimental	A166 is administered intravenously at a dose of 4.8 mg/kg every 21 (±3) days (q3w).	Drug: A166
T-DM1	Active Comparator	T-DM1 is administered intravenously at a dose of 3.6 mg/kg every 21 (±3) days (q3w).	Drug: T-DM1

Interventions

Name	Type	Description	Arm Group Labels	Other Names
A166	Drug	intravenous(IV) infusion (Q3W)	A166
T-DM1

Outcomes Module

Primary Outcomes

Measure	Description	Time Frame
Progression-free survival (PFS)	PFS as assessed by BICR according to RECIST v 1.1	Randomization up to approximately 39 months

Secondary Outcomes

Measure	Description	Time Frame
Overall survival (OS)	OS, 1-year survival rate, 2-year survival rate, and 3-year survival rate.	Randomization up to approximately 48 months
Objective response rate(ORR)	ORR 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

Other Outcomes

Not provided

Eligibility Module

Eligibility Criteria

Inclusion Criteria:

Male or female patient ≥ 18 years and ≤ 75 years when signing the informed consent form.
Breast cancer patients by histopathology and/or cytology documented.
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).
Have previously received taxanes.
Patients must have experienced disease progression or intolerance during or after the most recent treatment prior to randomization.
At least one measurable lesion according to RECIST 1.1 criteria

Exclusion Criteria:

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

Accepts Healthy Volunteers

Sex

All

Sex/Gender Based

Not provided

Sex/Gender Description

Not provided

Minimum Age

18 Years

Maximum Age

75 Years

Standard Ages

AdultOlder Adult

Study Population

Not provided

Sampling Method

Not provided

Facility	Status	City	State	ZIP	Country	Contacts
Fudan University Shanghai Cancer Center		Shanghai	Shanghai Municipality	200032	China

IPD Sharing Statement Module

Plan to Share IPD

Description

Not provided

Types

Not provided

Time Frame

Not provided

Access Criteria

Not provided

URL

Not provided