A Study to Compare DB-1303/BNT323 Versus T-DM1 in Breast Cancer

NCT06265428 | Active Not Recruiting Phase 3 FDA Drug

• 2 other identifiers: DB-1303-O-3001CTR20233403
• Study Type: interventional
• Target: 228
• Locations: 1 country
• Sites: 48

Brief Summary

This study is designed to compare efficacy and safety of DB-1303/BNT323 versus T-DM1 in HER2-positive, unresectable and/or metastatic breast cancer patients previously treated with trastuzumab and taxane.

Conditions

HER2-positive Breast Cancer

Keywords

HER2-positive; Breast Cancer; BC

Outcome Measures

Primary Outcomes (1)

• Progression Free Survival (PFS) by Blinded Independent Central Review (BICR) assessment per Response Evaluation Criteria in Solid Tumors Version 1.1 (RECIST 1.1)

  Defined as the time from randomization to the first documented disease progression per RECIST 1.1 as assessed by BICR or death due to any cause, whichever occurs first

  Up to approximately 24 months.

Secondary Outcomes (12)

• Overall Survival (OS)

  Up to approximately 24 months.

• Progression Free Survival (PFS) by Investigator assessment per RECIST 1.1

  Up to approximately 24 months.

• Objective response rate (ORR) by BICR and investigator assessment per RECIST 1.1

  Up to approximately 24 months.

• Duration of response (DoR) by BICR and investigator assessment per RECIST 1.1

  Up to approximately 24 months.

• PK parameters: maximum observed concentration (Cmax)

  Up to approximately 24 months.

Study Arms (2)

DB-1303/BNT323

EXPERIMENTAL

Enrolled patients will receive DB-1303/BNT323 by intravenous (I.V.) infusion

Drug: DB-1303/BNT323

T-DM1

EXPERIMENTAL

Enrolled patients will receive T-DM1 by I.V. infusion

Drug: T-DM1

Interventions

DB-1303/BNT323 DRUG

Administered I.V.

DB-1303/BNT323

T-DM1 DRUG

Administered I.V.

T-DM1

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Male or female adults ≥ 18 years at the time of voluntary signing of informed consent.
• Pathologically confirmed unresectable or metastatic HER2 positive breast cancer previously treated with trastuzumab and taxane
• Eastern Cooperative Oncology Group (ECOG) performance status score is 0 or 1.
• Presence of at least one measurable lesion according to RECIST v1.1
• Expected survival time ≥ 12 weeks.
• Patients must give informed consent to this study and voluntarily sign written informed consent form prior to the study.

You may not qualify if:

• Prior anti-HER2 ADC therapy.
• Previous history of interstitial lung disease/noninfectious pneumonitis/radiation pneumonitis requiring steroid therapy.
• Known serious hypersensitivity to the active ingredients of the study drug, inactive ingredients in the formulation, or other antibody drugs.
• Multiple primary malignancies within 3 years, except for adequately resected non-melanoma skin cancer, curatively treated in situ tumor, or contralateral breast cancer
• Uncontrolled infection requiring intravenous antibiotics, antiviral or antifungal agents, autoimmune disease requiring treatment, uncontrolled diabetes, hypertension, or other systemic disease that makes compliance with study procedures difficult
• Unrecovered toxicity from prior anticancer therapy, defined as toxicity (except for alopecia) not recovered to ≤Grade 1 (NCI-CTCAE v5.0) or baseline.

Sponsors & Collaborators

• DualityBio Inc.: lead
• BioNTech SE: collaborator

Study Sites (48)

015

Bengbu, Anhui, 233000, China

Location

016

Hefei, Anhui, 230001, China

Location

029

Hefei, Anhui, 230601, China

Location

001

Beijing, Beijing Municipality, 100039, China

Location

010

Beijing, Beijing Municipality, 100142, China

Location

038

Jilin, Changchun, 130022, China

Location

036

Fuzhou, Fujian, 350014, China

Location

037

Xiamen, Fujian, 361003, China

Location

023

Guangzhou, Guangdong, 510060, China

Location

024

Guangzhou, Guangdong, 510080, China

Location

026

Guangzhou, Guangdong, 510120, China

Location

028

Huizhou, Guangdong, 516001, China

Location

017

Nanning, Guangxi, 530021, China

Location

022

Nanning, Guangxi, 530021, China

Location

043

Haikou, Hainan, 570102, China

Location

045

Baoding, Hebei, 071000, China

Location

048

Shijiazhuang, Hebei, 050011, China

Location

020

Haerbin, Heilongjiang, 150081, China

Location

018

Luoyang, Henan, 471003, China

Location

006

Zhengzhou, Henan, 450003, China

Location

005

Zhengzhou, Henan, 450052, China

Location

011

Wuhan, Hubei, 430030, China

Location

009

Wuhan, Hubei, 430079, China

Location

030

Changsha, Hunan, 410005, China

Location

027

Nanjing, Jiangsu, 210009, China

Location

004

Nanjing, Jiangsu, 210029, China

Location

044

Xuzhou, Jiangsu, 221006, China

Location

014

Nanchang, Jiangxi, 330006, China

Location

008

Changchun, Jilin, 130021, China

Location

032

Dalian, Liaoning, 116021, China

Location

040

Binzhou, Shandong, 256603, China

Location

031

Jinan, Shandong, 250013, China

Location

047

Jinan, Shandong, 250117, China

Location

012

Linyi, Shandong, 276003, China

Location

039

Yantai, Shandong, 264001, China

Location

002

Shanghai, Shanghai Municipality, 200032, China

Location

046

Shanghai, Shanghai Municipality, 200120, China

Location

035

Taiyuan, Shanxi, 030013, China

Location

003

Xi’an, Shanxi, 710061, China

Location

007

Chengdu, Sichuan, 610041, China

Location

041

Neijiang, Sichuan, 641100, China

Location

034

Yibin, Sichuan, 644000, China

Location

021

Tianjin, Tianjin Municipality, 300060, China

Location

013

Ürümqi, Xinjiang, 830011, China

Location

033

Kunming, Yunnan, 650118, China

Location

019

Hangzhou, Zhejaing, 310022, China

Location

025

Hangzhou, Zhejiang, 310003, China

Location

042

Hangzhou, Zhejiang, 310016, China

Location

MeSH Terms

Conditions

Breast Neoplasms

Condition Hierarchy (Ancestors)

Neoplasms by Site; Neoplasms; Breast Diseases; Skin Diseases; Skin and Connective Tissue Diseases

Study Officials

• Lily Hu

  DualityBio Inc.

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: phase 3
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 5, 2024
• First Posted: February 20, 2024
• Study Start: January 29, 2024
• Primary Completion: February 1, 2026
• Study Completion: February 1, 2026
• Last Updated: October 20, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

CN (48)