SHANGHAI, CHINA and BOSTON, MA,USA_-November 7, 2025—Argo Biopharmaceutical Co., Ltd. (Argo Biopharma), a clinical-stage small interfering RNA (siRNA) therapeutics company, today announced it will present Phase I data for BW-20805 at the American College of Allergy, Asthma & Immunology (ACAAI) 2025 Annual Scientific Meeting , taking place November 6–10 in Orlando, Florida, USA.
BW-20805 is an investigational siRNA therapy that targets and inhibits prekallikrein (PKK), a well-validated target for hereditary angioedema (HAE) treatment, offering the possibility of prevention of HAE attacks with a significant, long-term effect.
The poster presentation (POSTER ID: R094) , titled “Hereditary Angioedema Prophylaxis With Prekallikrein siRNA-Phase 1 Safety Outcomes And Prekallikrein Levels ”, will be presented throughout the ACAAI meeting. These data highlight that BW-20805 was well tolerated and demonstrated a favorable safety profile and achieved rapid, profound, and sustained reductions in plasma PKK levels.
Key findings :
- BW-20805 was generally well tolerated across all dose levels (50–600 mg), with no dose-dependent increase in treatment-emergent adverse events (TEAEs).
- No deaths, serious adverse events (SAEs) related to study drug, or discontinuations due to TEAEs were reported.
- Treatment with BW-20805 led to rapid, profound, and durable reductions in plasma PKK levels, achieving mean maximum reductions of approximately 75% (50 mg), 87% (150 mg),94% (300 mg), and 95% (600 mg).
- PKK suppression was sustained for up to 24 weeks, supporting the potential for 6-month dosing intervals.
- Other pharmacodynamic biomarkers, including plasma proenzyme activation and cleaved high-molecular-weight kininogen (cHMWK), also showed significant reductions, reinforcing the drug’s biological activity.
“We are pleased with the results shared at ACAAI, showing that BW-20805 was well tolerated across all dose levels, with rapid, profound, and durable reductions in plasma PKK levels achieved,” said Dr. Dongxu Shu, co-founder and Chief Executive Officer of Argo Biopharma. “We look forward to further advancing BW-20805 as a potential long-acting and effective therapy for people living with HAE.”
About Hereditary angioedema(HAE)
Hereditary angioedema (HAE) is a rare genetic condition that causes sudden and unpredictable swelling in different parts of the body. In severe cases, it can affect the throat and become life-threatening, with a mortality rate of up to 40% 1. HAE affects about 1.5 people per 100,000 worldwide 2. Current treatments require frequent dosing, highlighting the need for long-acting, preventive therapies. BW-20805 targets human hepatic PKK mRNA to inhibit PKK gene expression, offering the potential for effective prevention of HAE attacks with a significant and longer-lasting therapeutic effect.
About Argo Biopharma
Argo Biopharma is a clinical-stage biotechnology company committed to developing next-generation RNAi therapeutics to provide better treatment options for patients worldwide. The company has established a robust and diverse pipeline of RNAi molecule candidates targeting a wide range of indications, including cardiovascular diseases, viral infections, metabolic conditions, and specialty/rare diseases. Currently, Argo Biopharma has six RNAi candidates in clinical development.
For more information, visit www.argobiopharma.com .
INVESTOR & MEDIA INQUIRIES
Argot Partners
argobiopharma@argotpartners.com
References：
1. Pedro Giavina-Bianchi，et at.CLINICS(2011);66(9):1627-1636
2. Aygören-Pürsün, E., et al. (2018). Orphanet J Rare Dis 13(1): 73.
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