Bowave Pharmaceuticals to Present Updated Phase II Data of siRNA Therapy BW-20805 for Hereditary Angioedema at EAACI 2026
Argo
RNAi Drug Developer
June 8, 2026Argo Biopharma Co., Ltd. (“Argo Biopharma”), a clinical-stage biotechnology company, has been selected to present updated Phase II clinical data on BW-20805 in the themed report session at the 2026 Annual Congress of the European Academy of Allergy and Clinical Immunology (EAACI). The congress will be held in Istanbul, Turkey, from June 12 to 15, 2026, with presentations also available via an online platform.
BW-20805 is an siRNA therapy targeting prekallikrein (PKK). By selectively inhibiting PKK expression, it holds promise for preventing attacks of hereditary angioedema (HAE) and demonstrates significant potential for long-acting therapeutic effects. PKK and its active form, kallikrein, are well-validated therapeutic targets in the current HAE treatment landscape.
Dr. Shu Dongxu, Co-founder and CEO of Argo Biopharma, stated, “We are delighted that the Phase II clinical data for BW-20805 has been selected for presentation at the 2026 EAACI Congress in the plenary session. Following the presentation of related project data at the 2025 Annual Meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI), this selection by EAACI further underscores the significant progress achieved by the program. We look forward to sharing our latest research findings and continuing to advance the clinical development of this therapy to provide better treatment options for patients.”
Poster (Poster No.: D1.363) titled “Long-Acting Prophylactic Injection BW-20805 Significantly Reduces Attack Rate in Hereditary Angioedema—Update on Phase II Clinical Study Data” showed that BW-20805 significantly reduced plasma prekallikrein (PKK) levels and markedly decreased the HAE attack rate, with a consistently favorable safety profile, supporting further evaluation of a long-acting dosing regimen administered every 6 months (Q6M).
Primary Research Findings
As of the data cutoff date, the HAE attack rate decreased by 99% in the 600 mg Q24W group, with 83% (5/6) of patients remaining attack-free; it decreased by 93% in the 300 mg Q24W group, with 60% (3/5) of patients being attack-free; and it decreased by 95% in the 300 mg Q12W group, with 60% (3/5) of patients remaining attack-free during the period.
Plasma PKK levels exhibited a rapid and significant decline. On Day 85, the mean reduction in plasma PKK levels exceeded 94% in the combined 300 mg dose group and reached approximately 96% in the 600 mg dose group. Throughout the 169-day follow-up period, PKK inhibition remained above 90% across all three study groups.
BW-20805 demonstrated a favorable safety and tolerability profile across the three dose groups, comprising a total of 18 subjects. No serious adverse events or severe adverse events related to the study drug were observed during the study. Furthermore, no treatment-emergent adverse events leading to subject withdrawal or death occurred. All injection site reactions were mild and transient, resolving spontaneously without the need for medical intervention.
About Hereditary Angioedema (HAE)
Hereditary Angioedema (HAE) is a rare genetic disorder that causes sudden, unpredictable swelling in various parts of the body. In severe cases, laryngeal edema can occur, with a mortality rate as high as approximately 40%.1. It is estimated that approximately 1.5 individuals per 100,000 population worldwide are affected by this disease.2Current therapies require frequent administration, resulting in a significant unmet need among patients for long-acting prophylactic treatment regimens. BW-20805 targets human hepatic PKK mRNA to inhibit PKK gene expression, thereby holding promise for highly effective and durable prevention of HAE attacks.
References:
1.Pedro Giavina-Bianchi P, et al. (2011). CLINICS 66(9): 1627–1636.
2.Aygören-Pürsün, E, et al. (2018). Orphanet J Rare Dis 13(1): 73.
About Argo Biopharma
Argo Biopharma is a clinical-stage biotechnology company dedicated to developing next-generation RNAi therapies to provide superior treatment options for patients worldwide. Leveraging its liver-targeted and extra-hepatic delivery technology platforms, the company has built a diversified RNAi drug development pipeline covering cardiovascular and metabolic diseases, specialized conditions, viral infections, central nervous system disorders, and rare diseases. Currently, Argo Biopharma has seven RNAi candidate drugs in clinical development.
