SHANGHAI, CHINA and BOSTON, USA – July 1, 2025—Argo Biopharmaceutical Co., Ltd. (Argo Biopharma), a clinical-stage small interfering RNA (siRNA) therapeutics company, today announced that National Medical Products Administration of China (NMPA) has granted Investigational New Drug (IND) approval for Phase II clinical trial of its innovative siRNA-based therapy, BW-20507 to be combined with standard-of-care PEG-IFNα for the treatment of chronic hepatitis B (CHB, chronic HBV). This combination approach is built on BW-20507's recent achievements, including Breakthrough Therapy Designation from NMPA for mono-therapy in June 2025, and a late-breaker poster presentation at the EASL Congress (European Association for the Study of the Liver Congress) in May 2025 in which best-in-class Phase I/IIa clinical data were presented.

The combination therapy employs two complementary mechanisms to combat HBV through distinct pathways: 

^. BW-20507, a small interfering RNA (siRNA) therapeutic, specifically targets the S-region of HBV mRNA to suppress viral gene expression to highly potent levels, resulting in rapid and sustained hepatitis B surface antigen (HBsAg) reduction

^. PEG-IFNα works through immunomodulation, enhancing both innate and adaptive immune responses against HBV-infected hepatocytes

Emerging evidence suggests that patients with reduced HBsAg levels show greater sensitivity to interferon treatment. By first reducing HBsAg burden through BW-20507's RNAi mechanism, the therapy may prime patients for enhanced IFN responsiveness, potentially leading to higher functional cure rates, shorter PEG-IFNα treatment duration, and improved tolerability compared to current interferon-based regimens. Preclinical and early clinical data have demonstrated promising HBsAg clearance when combining these two modalities, supporting this novel treatment potential.

"This IND approval represents a significant step forward in our quest to deliver higher functional cure rate for CHB patients," said Dr. Dongxu Shu, Co-Founder and the CEO of Argo Biopharma. "By combining the potent HBsAg reduction of our siRNA therapeutic with the immune-activating properties of PEG-IFNα, we aim to achieve sustained HBsAg clearance. This approval enables us to clinically validate this synergistic approach and potentially transform CHB treatment."

About Chronic Hepatitis B (CHB)

Chronic HBV affects approximately 296 million individuals globally, resulting in an estimated 820,000 deaths each year due to complications including cirrhosis, liver decompensation, and hepatocellular carcinoma (HCC). Currently, there remains a significant unmet medical need for functional cure treatments for CHB. siRNA therapies, which target viral mRNA, represent a promising pathway to a functional cure.

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 drug 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 .