Duality Biotherapeutics Presents Positive Study Results for DB-1311/BNT324 at ASCO GU Symposium 2026

Key Highlights

• Updated efficacy and safety results from the Phase 1/2 DB-1311-O-1001 study were presented at the prestigious American Society of Clinical Oncology (ASCO) Genitourinary (GU) Cancers Symposium 2026, held in San Francisco, USA, from February 26 to February 28, 2026.
• DB-1311/BNT324 is an investigational B7-H3 antibody-drug conjugate (ADC) being developed for heavily pretreated metastatic castration-resistant prostate cancer (mCRPC), including patients who have previously received lutetium 177 (177Lu)-PSMA-617 (Lu 177).
• 104 mCRPC patients were treated in the study, with a median follow-up of 9.2 months. Patients received either 6 mg/kg or 9 mg/kg doses every 3 weeks.
• Impressive efficacy data:
  • Confirmed Objective Response Rate (cORR): 34.5%
  • Disease Control Rate (DCR): 87.9%
  • Median Duration of Response (DOR): 10.2 months
  • Median radiographic Progression-Free Survival (rPFS): 11.3 months
  • 6-month and 9-month rPFS rates: 72.0% and 63.0%, respectively
  • 6-month and 9-month Overall Survival (OS) rates: 91.7% and 88.2%, respectively
  • PSA50 response rate: 35.4% (prostate-specific antigen reduction ≥50%)
  • Median PSA Duration of Response: 8.4 months
• Safety profile: The most common adverse events were nausea and hematological events, primarily Grade 1-2 and consistent with earlier reports.
• Impact of prior treatments:
  • Among patients previously treated with Lu 177 (n=34), efficacy outcomes were comparable to those without prior Lu 177, though PSA DOR was shorter in this subgroup.
  • Subgroup analysis showed cORR of 30.0% (post Lu 177) and 35.4% (no prior Lu 177), with DCR of 100% and 85.4%, respectively.
  • Median rPFS for both subgroups was 11.3 months (post Lu 177) and not estimable (no prior Lu 177), with 9-month OS rates of 86.2% and 88.5%.
• Regulatory milestones: In 2024, the US FDA granted DB-1311 Fast Track Designation for advanced/unresectable or metastatic CRPC and Orphan Drug Designations for esophageal squamous cell carcinoma (ESCC) and small cell lung cancer (SCLC).
• Ongoing clinical development: DB-1311/BNT324 is currently being further studied in a global Phase 3 trial (NCT07365995) for taxane-naïve mCRPC, with potential for combination usage and expansion into earlier treatment lines.

Implications for Shareholders and Potential Price Sensitivity

• The presentation of positive efficacy and safety data at the ASCO GU Symposium 2026 is a significant milestone. Notably, the substantial objective response rates, disease control rates, and prolonged progression-free survival in a heavily pretreated, difficult-to-treat patient population could position DB-1311/BNT324 as a leading therapy in mCRPC.
• Regulatory designations by the FDA (Fast Track and Orphan Drug) may accelerate the development and commercial potential of DB-1311/BNT324, which is a key value driver for the company.
• Continued positive data and ongoing Phase 3 trials support the possibility of eventual regulatory approval and commercialization, but shareholders should remain aware of risks associated with clinical development.
• Any setbacks or adverse findings in ongoing or future studies could negatively impact share value. The company explicitly warns that there is no assurance DB-1311/BNT324 will ultimately be successfully developed, marketed, or commercialized.

About DB-1311/BNT324

DB-1311/BNT324 is a next-generation B7-H3 antibody-drug conjugate with a silenced Fc region, designed to maximize tumor targeting and minimize off-target toxicity. B7-H3 is highly expressed across multiple tumor types, making this ADC a versatile candidate. The drug incorporates a potent cytotoxic payload with a stable linker, and is tailored to attack B7-H3 overexpressing tumor cells, including prostate, lung, breast, esophageal, and head and neck cancers.

Board Statement and Management

The announcement is authorized by Dr. Zhu Zhongyuan, Chairman, Executive Director, and CEO. The board comprises seasoned executives and independent non-executive directors, whose collective experience is vital for the ongoing development and potential commercialization of DB-1311/BNT324.

Disclaimer

Cautionary Statement: There is no assurance that Duality Biotherapeutics, Inc. will successfully develop, market, or commercialize DB-1311/BNT324. Investors are advised to exercise caution when trading the shares of the company and to be aware that the clinical development process is inherently risky and subject to potential delays, setbacks, or failures.

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