Preliminary Data from Two Clinical Trials with ADC Candidates were Presented Orally at the 2025 ASCO Annual Meeting

SHANGHAI and CHICAGO, June 5, 2025 /PRNewswire/ — The 2025 ASCO Annual Meeting is taking place in Chicago, US, from May 30 to June 3. Duality Bio (HKEX: 9606.HK) presented the preliminary data of two clinical trials, HER3 ADC candidate DB-1310 and B7H3 ADC candidate DB-1311/BNT324, which is being jointly developed with BioNTech, in Oral/Rapid Oral presentations.

B7H3 ADC candidate DB-1311/BNT324:

Data from the ongoing Phase 1/2 clinical trial (NCT05914116) in patients with heavily pre-treated castration-resistant prostate cancer (CRPC) were presented during an oral session on BNT324/DB-1311, an B7H3-targeted ADC candidate.

The data indicated early clinical activity and a manageable safety profile with low discontinuation rates. Most common adverse events were gastrointestinal and hematologic toxicities. In the 52 efficacy evaluable patients with heavily pretreated CRPC based on RCIST v1.1, the confirmed objective response rate (cORR) was 30.8%, DCR was 90.4%. Among 68 evaluable patients, the 6-month rPFS rate was 69.8%. Similar outcomes were observed across both dose levels (6 mg/kg or 9 mg/kg). Outcomes appeared better in earlier treatment lines and in patients who received one prior NHT, while antitumor activity was also observed in later lines and regardless of type of prior treatment or metastatic site.

The clinical trial is currently enrolling post Lu-177 CRPC (Cohort 11) and taxane-naïve CRPC (Cohort 12).

As the incidence rate of prostate cancer is increasing^[1],1 there is a high unmet need for new effective therapies for patients with heavily pretreated CRPC^[1]. The DB-1311/BNT324 program received Fast Track Designation by the U.S. Food & Drug Administration (“FDA”) for the treatment of patients with advanced/unresectable or metastatic CRPC that has progressed on or after standard systemic regimens in 2024.

HER3 ADC DB-1310：

Data from the first-in-human Phase I/IIa study (NCT05785741) presented by Professor Aaron E. Lisberg of the University of California, Los Angeles (UCLA), demonstrated that DB-1310 showed encouraging efficacy and a manageable safety profile in patients with advanced solid tumors who had failed standard treatments.

Among 123 efficacy evaluable patients, the unconfirmed objective response rate (uORR) was 31%, and the disease control rate (DCR) reached 84%. Notably, efficacy was particularly striking in the key subgroup of patients with EGFR-mutated non-small cell lung cancer (NSCLC) (n=46) where uORR reached 44%, DCR was 91%, median progression-free survival (mPFS) was 7.0 months, and median overall survival (mOS) was 18.9 months. The uORR reached an impressive 66.7% at the 5.5 mg/kg Q3W dose level (n=12).

In addition, DB-1310 was well-tolerated with a manageable safety profile. The most common treatment-related adverse events (TRAEs) were Grade 1-2 hematological and gastrointestinal events with a low treatment-related discontinuation rate of 3.5%.

These positive results support the continued development of DB-1310 in advanced solid tumors, particularly in patients with EGFR-mutated NSCLC. The company is advancing its global development program, including exploring DB-1310 as a monotherapy in additional tumor types, as well as exploring DB-1310 in combination with EGFR TKIs and HER2-targeted therapies.

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 2,000 patients for multiple clinical-stage ADC candidates.

Additionally, DualityBio have established strategic collaborations with global MNCs and leading biotech innovators. As a global ADC powerhouse, DualityBio is developing candidates including bispecific ADCs, novel-payload ADCs, and autoimmune ADCs. For more information, please visit www.dualitybiologics.com.