Shanghai, China, December 3^rd, 2025 — DualityBio (“DualityBio”, Stock Code: 9606.HK) announced that the Investigational New Drug (IND) application for its self-developed next-generation antibody-drug conjugate DB-1324 has been cleared by the U.S. Food and Drug Administration (FDA), enabling the initiation of a clinical trial in the United States.

The trial is a phase 1/2, multicenter, open-Label, first-in-human study to assess the safety,

tolerability, pharmacokinetics, and preliminary antitumor activity of DB-1324 in participants with advanced/metastatic gastrointestinal tumors.

DB-1324 is a next-generation antibody-drug conjugate developed based on DualityBio's proprietary DITAC (Duality Immune Toxin Antibody Conjugates) platform. In 2024, DualityBio entered into an exclusive ex-China licensing agreement with GlaxoSmithKline (GSK) for DB-1324. Previously, in October 2025, DB-1324 received approval from an Australian Human Research Ethics Committee (HREC) and a Clinical Trial Notification (CTN) clearance from the Therapeutic Goods Administration (TGA) of Australia. The global clinical development of this product is progressing steadily, holds promise as a potential new treatment option for patients worldwide.

About DualityBio

Duality Biotherapeutics (HKEX:09606) is a clinical-stage biotech company dedicated to the discovery and development of next-generation ADCs 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 20 countries and has enrolled over 2,700 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 novel ADCs, including bispecific ADC candidates, novel-payload ADC candidates, and autoimmune ADC candidates.

For more information, please visit www.dualitybiologics.com

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