Shanghai, China– May 8, 2026 –DualityBio (Stock Code: 9606.HK) announced preliminary  data of a Phase 2 cohort evaluating sacituzumab drozuntecan (DB-1305/BNT325), an investigational TROP2‑targeted antibody‑drug conjugate (“ADC”) developed in collaboration with BioNTech, in combination with an investigational anti‑PD‑L1×VEGF‑A bispecific immunomodulator, for the first‑line treatment of advanced or metastatic triple‑negative breast cancer (a/mTNBC). This cohort is part of an ongoing Phase 1/2a, open-label, dose-escalation and expansion clinical trial in patients with advanced or metastatic solid tumors (NCT05438329) designed to evaluate the safety, tolerability, and preliminary anti-tumor activity of DB-1305/BNT325.

The data were presented in a Rapid Oral presentation at the 2026 European Society for Medical Oncology Breast Cancer (“ESMO Breast Cancer”) Annual Meeting in Berlin, Germany. The abstract for this study was previously published on the official ESMO BC website on April 30 (local time).

Following the determination of the recommended regimen in the Phase 1 dose-escalation stage, the Phase 2 expansion cohort enrolled patients with unresectable, advanced or metastatic TNBC who had received no prior systemic therapy. Patients received the investigational anti-PD-L1×VEGF-A bispecific immunomodulator (30 mg/kg once every 3 weeks) combined with sacituzumab drozuntecan (3.5 mg/kg once every 3 weeks). The primary endpoints of the clinical trial were investigator-assessed Objective Response Rate (ORR) and safety. The secondary endpoints included Disease Control Rate (DCR), Duration of Response (DoR), and Progression-Free Survival (PFS). The data cutoff date was February 28, 2026. PFS data were not mature at the time of analysis.

The analysis of the Phase 2 expansion cohort included 30 patients with advanced or metastatic TNBC, with a median age of 55.5 years (range: 34–84 years) and a median follow-up time of 7.7 months. The results demonstrated robust anti-tumor activity and a manageable safety profile of the combination regimen in patients with advanced TNBC. Among all patients, the unconfirmed objective response rate (uORR) was 83.3%, the confirmed objective response rate (cORR) was 76.7%, and the disease control rate (DCR) was 96.7%. Tumor shrinkage was observed in all 30 patients, with 95.2% of patients showed ongoing anti-tumor responses at 6 months.

The safety profile was manageable and as expected for TROP2-targeted ADCs. Grade ≥3 treatment-related adverse events (TRAEs) were reported in 13 of 30 patients (43.3%), and the discontinuation rate due to TRAEs was 3.3%. The most common TRAEs (>40%) were stomatitis, weight loss, alanine aminotransferase (ALT) increase, and alopecia, with most cases being Grade 1–2.

Dr. Hua Mou, Chief Medical Officer of DualityBio, stated:"These early data indicate encouraging signs of anti-tumor activity and a manageable safety profile of sacituzumab drozuntecan combined with an investigational anti-PD-L1×VEGF-A bispecific immunomodulator as a first-line treatment of patients with TNBC. They also underscore the design of the Company’s proprietary next-generation ADC technology platform in molecular design, payload optimization, and tumor-targeted delivery, aimed at enabling more precise target recognition, more stable conjugation structure, and more controlled payload release. This translates to enhanced anti-tumor activity while achieving a more robust and manageable overall safety profile. We will continue to focus on ADC technological innovation and global clinical development, grounded in scientific rigor, to deliver innovative therapies for cancer patients worldwide."

About DualityBio

Duality Biotherapeutics is a clinical-stage biotech company dedicated to the discovery and development of next-generation ADC to treat cancer and autoimmune diseases. DualityBio has successfully built several cutting-edge ADC technology platforms with global intellectual property rights. Leveraging a robust pipeline, DualityBio is conducting multiple global clinical trials across 17 countries, has enrolled over 3,200 patients for multiple clinical-stage ADC candidates. Additionally, DualityBio has established strategic collaborations with global MNCs and leading biotech innovators. As a global ADC powerhouse, DualityBio is developing bispecific ADCs, novel-payload ADCs, and autoimmune ADCs.

 For more information, please visit www.dualitybiologics.com.

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