NCT06018337

A Study of DB-1303/BNT323 vs Investigator's Choice Chemotherapy in HER2-Low, Hormone Receptor Positive Metastatic Breast Cancer (DYNASTY-Breast02)

A Phase 3, Randomized, Multi-center, Open-Label Study of DB-1303 Versus Investigator's Choice Chemotherapy in Human Epidermal Growth Factor Receptor 2 (HER2)-Low, Hormone Receptor Positive (HR+) Metastatic Breast Cancer Patients Whose Disease Has Progressed on Endocrine Therapy (ET) (DYNASTY-Breast02)

• Status: Active Not Recruiting
• Phase: Phase 3
• Study type: Interventional
• Enrollment: 541 (actual)
• Sponsor: DualityBio Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The goal of this clinical trial is to assess the efficacy of DB-1303/BNT323 compared with investigator's choice chemotherapy in terms of progression-free survival (PFS) by blinded independent central review (BICR) in the HR+, HER2-low (immunohistochemistry \[IHC\]2+/in situ hybridization \[ISH\]- and IHC 1+) population.

Detailed description

The study is a Phase III, Randomized, Multi-center, Open-label study in HER2-low, HR+ metastatic breast cancer subjects whose disease has progressed on at least 2 lines of prior ET or within 6 months of first line ET + Cyclin-dependent kinase (CDK) 4/6 inhibitor in the metastatic setting. The primary purpose of the study is to determine the efficacy and safety of DB-1303/BNT323 compared with investigator's choice single agent chemotherapy in the target population. Approximately 532 subjects with HER2 IHC 2+/ISH- and IHC 1+ (HER2-low\] expression will be randomized 1:1 across approximately 255 centers globally to receive either DB-1303 or investigator's choice single agent chemotherapy (capecitabine, paclitaxel or nab-paclitaxel) until Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 defined disease progression (PD), unless there is unacceptable toxicity, withdrawal of consent, or another criterion for discontinuation is met.

Conditions

• Metastatic Breast Cancer

Interventions

Type	Name	Description
DRUG	DB-1303/BNT323	IV
DRUG	Capecitabine	Oral
DRUG	Paclitaxel	IV
DRUG	Nab-paclitaxel	IV

Timeline

• Start date: 2024-01-18
• Primary completion: 2026-05-01
• Completion: 2028-07-01
• First posted: 2023-08-30
• Last updated: 2026-03-05

Locations

261 sites across 17 countries: United States, Argentina, Australia, Belgium, Canada, China, France, Germany, Hong Kong, Hungary, Israel, Italy, Poland, South Korea, Spain, Turkey (Türkiye), United Kingdom

Regulatory

• FDA-regulated drug study