SHANGHAI/MADRID, China, July 17, 2026 — The 2026 European Society for Medical Oncology (ESMO) Congress will officially convene from October 23 to October 27 in Madrid, the capital of Spain. Duality Biotherapeutics, Inc. (DualityBio, HKEX: 9606.HK, or "the Company") will present new clinical data from several clinical trials at this year's congress. These presentations will cover elfetabart drozuntecan (also known as DB-1311/BNT324 or Elfe-D), a B7-H3-targeted antibody-drug conjugate (ADC) being developed in collaboration with BioNTech, as well as DB-1310, a proprietary HER3-targeted ADC developed independently by the Company.

The titles of the relevant research abstracts have been published on the official 2026 ESMO website. The research results to be presented are as follows:[SV1] 

Elfetabart drozuntecan in Patients with Advanced Solid Tumors

l  Abstract Title: EIfetabart drozuntecan (Elfe-D; DB-1311/BNT324 [B7H3 ADC]) + pumitamig (PD-L1 x VEGF -A bsAb) in patients with advanced solid tumors: First results from a global phase 2 trial

l  Presentation Format: Proffered Paper Presentation

l  Abstract Number: 9990

l  Meeting time: Local time: 14:45–16:15, October 24

Elfetabart drozuntecan in Patients with PROC

l  Abstract Title: Elfetabart drozuntecan (Elfe-D; DB-1311/BNT324 [B7H3 ADC]) in patients with platinum-resistant ovarian cancer (PROC): Efficacy and safety data from a Phase 2 dose optimization cohort

l  Presentation Format: Poster

l  Abstract Number: 1255P

l  Meeting time: Local time: 12:00–12:45, October 26

DB-1310 in Patients with  BC

l  Abstract Title: Efficacy, safety, and biomarker analysis of DB-1310 (HER3-targeted ADC) in pretreated HR+/HER2- breast cancer: Updated global phase 1/2a trial

l  Presentation Format: Poster

l  Abstract Number: 1846P

l  Meeting time: Local time: 12:00–12:45, October 24

About Elfetabart drozuntecan (DB-1311/BNT324)

Elfetabart drozuntecan (also known as DB-1311/BNT324 or Elfe-D）is a next-generation topoisomerase-I-inhibitor-based ADC candidate targeting the immune checkpoint protein B7-H3. The transmembrane glycoprotein B7-H3 plays a critical role in the anti-tumor immune response and the shaping of the tumor microenvironment. B7-H3 is overexpressed in a range of solid tumors, with limited expression in healthy tissues, and has been associated with disease progression and very poor prognosis.1 Preclinical studies have shown that elfetabart drozuntecan exhibits antitumor activity in various solid tumor models.2 Clinical data from the ongoing Phase 1/2 trial (DB-1311-O-1001 NCT05914116, DB-1311-201 NCT06953089, BNT324-01 NCT06892548)  has demonstrated antitumor activity and a manageable safety profile for elfetabart drozuntecan in patients with advanced solid tumors.3

Elfetabart drozuntecan is currently being evaluated in a pivotal Phase 3 clinical trial (NCT07365995) in patients with metastatic castration-resistant prostate cancer (mCRPC) and in a Phase 1/2 clinical trial (NCT05914116) in patients with advanced or metastatic solid tumors.

In addition, two ongoing clinical trials are evaluating the potential of elfetabart drozuntecan in combination with pumitamig, an investigational PD-L1xVEGF-A bispecific immunomodulator being developed by BioNTech and Bristol Myers Squibb. A Phase 2 clinical trial (NCT06953089) is evaluating the treatment combination in multiple solid tumors, and a Phase 1/2 clinical trial (NCT06892548), sponsored by BioNTech, is evaluating the treatment combination in patients with advanced/metastatic or relapsed/progressive small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

About DB-1310

DB-1310 is a proprietary HER3-directed ADC developed by the company based on its DITAC platform. It targets the HER3 receptor, which is highly expressed in various solid tumors and closely associated with drug resistance. DB-1310 is designed to address the unmet clinical needs of patients with EGFR-mutated NSCLC who have disease progression on or after third-gen EGFR tyrosine kinase inhibitors (TKIs), and it demonstrated broader applications in other indications, such as breast cancer. Having shown excellent antitumor activity in patients with EGFR-mutated NSCLC and HR+/HER2- breast cancer, DB-1310 has been granted Fast Track designation by the U.S. Food and Drug Administration (FDA). Early clinical studies indicate that DB-1310 possesses a favorable safety profile and preliminary efficacy in patients with advanced solid tumors who have failed multiple lines of prior therapy.

Currently, a global Phase I/IIa clinical trial is underway to primarily evaluate the efficacy and safety of DB-1310 in several indications, including EGFR-mutated NSCLC and HR+/HER2- breast cancer. Furthermore, there are plans to expand its use into front-line treatment through combination therapy strategies to fulfill the clinical needs of a broader patient population.

About DualityBio 

DualityBio is a clinical-stage innovative biopharmaceutical company dedicated to developing next-generation antibody-drug conjugates (ADCs) for patients with cancer and autoimmune diseases. The Company has successfully built multiple next-generation ADC technology platforms with global intellectual property rights. Grounded in a deep understanding of disease biology, DualityBio has established a robust clinical-stage ADC pipeline and is conducting multiple global, multicenter clinical trials across nearly 20 countries, with over 3,500 patients enrolled to date. Furthermore, DualityBio has entered into several out-licensing collaborations with global pharmaceutical companies and leading innovative biotech firms. Serving as a global engine for ADC innovation, DualityBio continues to develop next-generation novel ADCs, including bispecific ADCs, ADCs with novel payloads, and autoimmune ADCs.

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

Media Contact: PR@dualitybiologics.com

Investor Contact: IR@dualitybiologics.com

Reference 

1. Ranjana K. Kanchan, et al. Biochim Biophys Acta Rev Cancer. 2022 Sep;1877(5):188783.

2.Li C, Yao J, et al. Cancer Res (2023) 83 (7_Supplement):2967.

3. Data on file.