May 22, 2026，Shanghai, China, – Duality Biotherapeutics, Inc. (DualityBio, HKEX: 9606.HK, the “Company”) today announced that the first patient has been dosed in a global pivotal Phase 3 clinical trial evaluating DB-1311/BNT324 for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have not received prior taxane-based chemotherapy.

DB-1311/BNT324 is a next-generation antibody-drug conjugate (“ADC”) candidate targeting the transmembrane glycoprotein B7-H3, an immune checkpoint protein which is overexpressed in CRPC and often associated with immune evasion and poor prognosis for patients. DB-1311/BNT324 is being developed in collaboration with BioNTech.

Prostate cancer is the second leading cause of cancer-related deaths among men worldwide.¹ While in general patients with metastatic prostate cancer initially respond to hormone therapy, most patients progress after 18-24 months and develop CRPC, an advanced form of prostate cancer, leading to a poor prognosis for these patients. The 5-year survival rate for patients with metastatic CRPC is only around 36%.²

The global randomized, open-label Phase 3 clinical trial (NCT07365995) sponsored by BioNTech , will evaluate the efficacy and safety of DB-1311/BNT324 versus docetaxel plus prednisone/prednisolone, a current standard of care, in patients with mCRPC. The primary endpoints are radiographic progression-free survival (rPFS) assessed by blinded independent central review (BICR) and overall survival (OS). The trial is expected to enroll approximately 736 patients with metastatic CRPCwho have not received prior taxane therapy in the mCRPC setting.

The trial is based on results from an ongoing Phase 1/2 clinical trial (NCT05914116) evaluating DB-1311/BNT324 in patients with heavily pre-treated metastatic CRPC patients. The data from the Ph1/2 clinical trial showed encouraging anti-tumor activity of DB-1311/BNT324 in 129 patients with heavily pre-treated metastatic CRPC and a manageable safety profile. These data were presented at the 2026 American Society of Clinical Oncology Genitourinary Cancers Symposium (ASCO GU). 

Dr. Mu Hua, Global Chief Medical Officer of DualityBio, stated: ““The first patient dosing in a global Phase 3 pivotal trial of DB‑1311/BNT324 in mCRPC represents a major strategic milestone for DualityBio. This program underscores our commitment to addressing a high unmet medical need in advanced prostate cancer, where novel safer, more effective, and durable treatment options remain urgently required. Advancing this B7‑H3 ADC into a registrational Phase 3 trial in the first‑line setting reinforces our global clinical leadership in next‑generation ADCs and validates the clinical profile observed in our earlier trials. Together with BioNTech, we are executing our global development strategy, with the goal of bringing this therapy to patients worldwide as quickly as possible. This pivotal step further strengthens our broad oncology pipeline and solidifies our position as a fully integrated, global biopharmaceutical company aiming to deliver innovative medicines to patients across key markets.””

About DB-1311/BNT324

DB-1311/BNT324 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. It 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.³ Preclinical studies have shown that BNT324/DB-1311 exhibits antitumor activity in various solid tumor models.⁴ Preliminary data from the ongoing Phase 1/2 trial has demonstrated antitumor activity and a manageable safety profile for BNT324/DB-1311 in patients with advanced solid tumors.⁵ BNT324/DB-1311 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 clinical trials are ongoing evaluating the potential of DB-1311/BNT324 in combination with an investigational PD-L1xVEGF-A bispecific immunomodulator: a Phase 2 clinical trial (NCT06953089) evaluating the treatment combination in multiple solid tumors, and a Phase 1/2 clinical trial (NCT06892548) 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 DualityBio

DualityBio is a clinical-stage innovative biopharmaceutical company focused on 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. Based on in-depth research and exploration of disease biological mechanisms, DualityBio has a robust clinical ADC pipeline, with over 3,200 patients enrolled in multiple global multi-center clinical trials across more than 17 countries. Meanwhile, DualityBio has entered into several overseas licensing collaborations with global pharmaceutical companies and top innovative biotechs. As a global ADC innovation engine, DualityBio continues to develop next-generation novel ADCs, including bispecific ADCs, ADCs with novel payload mechanisms, and ADCs for autoimmune diseases.

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

Media Contact: PR@dualitybiologics.com

Investor Contact: IR@dualitybiologics.com

1 Cancer TODAY. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. Available at: https://gco.iarc.who.int (last access: 20.06.2024).

2 SEER*Explorer: An interactive website for SEER cancer statistics. Cancer Stat Facts: Prostate Cancer. 2024 Apr 17. Available at: https://seer.cancer.gov/statfacts/html/prost.html (last access: 12.05.2026).

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

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

5 Data on file.