SHANGHAI, China, May 26, 2026 — DualityBio (HKEX: 9606.HK, or "the Company") announced today that the Phase I/II clinical trial of DB-1418/AVZO-1418, a novel EGFR/HER3 bispecific antibody-drug conjugate (ADC) being developed in collaboration with Avenzo Therapeutics, Inc. ("Avenzo"), has completed the first patient enrollment and dosing in China for the treatment of advanced solid tumors.

DB-1418/AVZO-1418 is a potential best-in-class BsADC targeting EGFR and HER3. EGFR and HER3 are co-expressed in many solid tumors, including non-small cell lung cancer (NSCLC). In addition, HER3 overexpression is a known resistance mechanism to EGFR inhibition, making the therapeutic combination of targeting both EGFR and HER3 a rational BsADC approach.

This study is a Phase I/II, multicenter, open-label, first-in-human (FIH) trial designed to assess the safety, tolerability, and preliminary clinical activity of DB-1418/AVZO-1418 in patients with advanced solid tumors. DualityBio is enrolling patients in Greater China¹, and Avenzo is enrolling patients in regions outside of Greater China.

In January 2025, the Company officially announced that it had entered into an exclusive license agreement pursuant to which Avenzo will develop, manufacture, and commercialize DB-1418/AVZO-1418 globally (excluding Greater China).

In November 2025, Avenzo announced DB-1418/AVZO-1418 received Fast Track Designation (FTD) from the U.S. Food and Drug Administration (FDA) for the treatment of patients with unresectable, locally advanced, or metastatic non-small cell lung cancer (NSCLC) with an EGFR exon 19 deletion or exon 21 L858R mutation, whose disease has progressed on or after therapy with an EGFR tyrosine kinase inhibitor (TKI).

1.Greater China includes People’s Republic of China, Hong Kong, Macau and Taiwan.

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 3,200 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.

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