Comparing two treatments for HER2-positive breast cancer

A Phase III, Multicenter, Open-label, Randomized Study to Compare DB-1303 Versus T-DM1 in Patients With HER2-positive Unresectable/Metastatic Breast Cancer Who Have Been Treated With Trastuzumab and a Taxane (Dynasty-Breast01)

This study is testing whether a new treatment called DB-1303/BNT323 works better than T-DM1 for people with advanced HER2-positive breast cancer who have already been treated with other medications.

Quick facts

• Phase: Phase 3
• Study type: Interventional
• Enrollment: 224 (estimated)
• Ages: 18 Years and up
• Sex: All
• Sponsor: DualityBio Inc. (Industry-sponsored)
• Drugs / interventions: trastuzumab, radiation
• Locations: 48 sites (Bengbu, Anhui and 47 other locations)
• Trial ID: NCT06265428 on ClinicalTrials.gov

What this trial studies

This study aims to compare the efficacy and safety of DB-1303/BNT323 against T-DM1 in patients with HER2-positive, unresectable, or metastatic breast cancer who have previously been treated with trastuzumab and taxanes. It is a randomized, controlled, open-label, multicenter phase III trial involving approximately 224 participants. Patients will be assigned in a 1:1 ratio to receive either DB-1303/BNT323 or T-DM1, with the goal of determining which treatment is more effective.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older with unresectable or metastatic HER2-positive breast cancer who have been previously treated with trastuzumab and taxanes.

Not a fit: Patients with prior anti-HER2 ADC therapy or serious hypersensitivity to the study drugs may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a more effective treatment option for patients with advanced HER2-positive breast cancer.

How similar studies have performed: Other studies have shown success with similar approaches in treating HER2-positive breast cancer, indicating potential for this trial's success.

Eligibility criteria

Inclusion Criteria:

* 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.

Exclusion Criteria:

* 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.

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

Where this trial is running

Bengbu, Anhui and 47 other locations

• 015 — Bengbu, Anhui, China (Recruiting)
• 016 — Hefei, Anhui, China (Recruiting)
• 029 — Hefei, Anhui, China (Recruiting)
• 001 — Beijing, Beijing, China (Recruiting)
• 010 — Beijing, Beijing, China (Recruiting)
• 038 — Jilin, Changchun, China (Recruiting)
• 036 — Fuzhou, Fujian, China (Recruiting)
• 037 — Xiamen, Fujian, China (Recruiting)
• 023 — Guangzhou, Guangdong, China (Recruiting)
• 024 — Guangzhou, Guangdong, China (Recruiting)
• 026 — Guangzhou, Guangdong, China (Recruiting)
• 028 — Huizhou, Guangdong, China (Recruiting)
• 017 — Nanning, Guangxi, China (Recruiting)
• 022 — Nanning, Guangxi, China (Recruiting)
• 043 — Haikou, Hainan, China (Recruiting)
• 045 — Baoding, Hebei, China (Recruiting)
• 048 — Shijiazhuang, Hebei, China (Recruiting)
• 020 — Haerbin, Heilongjiang, China (Recruiting)
• 018 — Luoyang, Henan, China (Recruiting)
• 006 — Zhengzhou, Henan, China (Recruiting)
• 005 — Zhengzhou, Henan, China (Recruiting)
• 011 — Wuhan, Hubei, China (Recruiting)
• 009 — Wuhan, Hubei, China (Recruiting)
• 030 — Changsha, Hunan, China (Recruiting)
• 027 — Nanjing, Jiangsu, China (Recruiting)
• 004 — Nanjing, Jiangsu, China (Recruiting)
• 044 — Xuzhou, Jiangsu, China (Recruiting)
• 014 — Nanchang, Jiangxi, China (Recruiting)
• 008 — Changchun, Jilin, China (Recruiting)
• 032 — Dalian, Liaoning, China (Recruiting)
• 040 — Binzhou, Shandong, China (Recruiting)
• 031 — Jinan, Shandong, China (Recruiting)
• 047 — Jinan, Shandong, China (Recruiting)
• 012 — Linyi, Shandong, China (Recruiting)
• 039 — Yantai, Shandong, China (Recruiting)
• 002 — Shanghai, Shanghai, China (Recruiting)
• 046 — Shanghai, Shanghai, China (Recruiting)
• 035 — Taiyuan, Shanxi, China (Recruiting)
• 003 — Xi'an, Shanxi, China (Recruiting)
• 007 — Chengdu, Sichuan, China (Recruiting)
• 041 — Neijiang, Sichuan, China (Recruiting)
• 034 — Yibin, Sichuan, China (Recruiting)
• 021 — Tianjin, Tianjin, China (Recruiting)
• 013 — Ürümqi, Xinjiang, China (Recruiting)
• 033 — Kunming, Yunnan, China (Recruiting)
• 019 — Hangzhou, Zhejaing, China (Recruiting)
• 025 — Hangzhou, Zhejiang, China (Recruiting)
• 042 — Hangzhou, Zhejiang, China (Recruiting)

Study contacts

• Study coordinator: Ren Yue

Conditions HER2-positive Breast Cancer; HER2-positive; Breast Cancer; BC