DUALITYBIO-B (09606): The global Phase 3 clinical trial of DYNASTY-Breast02 (NCT06018337) has reached its primary study endpoint.

DUALITYBIO-B (09606) announced that the global Phase 3 clinical trial DYNASTY-Breast02 (NCT06018337) has reached its primary study endpoint. The results showed that in patients with HR+/HER2-low metastatic breast cancer who had experienced disease progression after prior endocrine therapy and had not yet received chemotherapy, compared with the investigator's choice chemotherapy control group, pankangtuzumab (DB-1303/BNT323) (an investigational HER2-targeting antibody-drug conjugate (ADC)) achieved a statistically significant modest improvement in progression-free survival (PFS). As of this interim analysis, data for the secondary endpoint overall survival (OS) were not yet mature. The overall incidence of interstitial lung disease (ILD) reported in this study was higher than in previous clinical trials of pankangtuzumab, with the vast majority of events being Grade 1 or Grade 2. A small number of patients reported Grade 3-5 events. Apart from this, the overall safety profile of this study was broadly consistent with previous clinical trials, and no new safety signals were observed. The efficacy and safety data obtained as of this data cutoff suggest that, in light of the current treatment landscape for HR+/HER2-low metastatic breast cancer, the potential clinical benefit of this study regimen for this specific patient population may be relatively limited. The Company and BioNTech SE (BioNTech, the Company's partner for pankangtuzumab) will further analyze and discuss the data and evaluate next steps. The Company and BioNTech are developing pankangtuzumab in three ongoing clinical trials, including two global Phase 3 clinical trials, one for HR+/HER2-low metastatic breast cancer (NCT06018337) and another for HER2-expressing recurrent endometrial cancer (NCT06340568); and a global Phase 1/2 clinical trial for patients with advanced/metastatic solid tumors (NCT05150691).