AusperBio Announces AHB-137 Monotherapy Achieved 30% Functional Cure Rate in HBe-negative CHB Patients on Stable Nucleos(t)ide Analogue (NA) Therapy

SAN FRANCISCO, Dec. 12, 2025 /PRNewswire/ -- AusperBio Therapeutics, Inc. and Ausper Biopharma Co., Ltd. (together AusperBio), a clinical-stage biotechnology company developing oligonucleotide-based therapies for functional cure of chronic hepatitis B (CHB), today announced full end-of-follow-up (EOF) data from its Phase IIa study (AB-10-8002) of AHB-137, the company's lead investigational HBV therapeutic product. Results were presented in an oral session at HEP-DART 2025 conference (December 7–11, Honolulu, USA).

The data demonstrated that finite-duration 24-week AHB-137 monotherapy achieved a 30% functional cure rate at Week 72 (EOF) in patients with baseline HBsAg 100–1,000 IU/mL. This finding strengthens clinical evidence supporting AHB-137's potential to serve as a backbone for future HBV cure regimens.

Key EOF Results (Week 72):

• Compelling Efficacy with Monotherapy
  In patients with baseline HBsAg 100–1,000 IU/mL, 30% of participants achieved functional cure (HBsAg <0.05 IU/mL and HBV DNA<LLOQ) in both 225 mg and 300 mg cohorts. In patients with baseline HBsAg 100–3,000 IU/mL, functional cure was achieved in 13% (225 mg) and 19% (300 mg). Based on these results, the 300 mg dose has been selected for further Phase II studies.
• Highly Sustained Off-Treatment Viral Replication Suppression
  After completing AHB-137 and discontinuing NA therapy, 100% of patients remained HBV DNA–negative for 24 weeks, confirming durable viral replication suppression off-treatment.
• Durable Off-Treatment HBsAg Suppression
  After completing AHB-137 and discontinuing NA therapy, pooled analysis across both dose groups showed that 89% and 82% of patients sustained complete response (HBsAg <0.05 IU/mL and HBV DNA<LLOQ) at Week 72, among patients with baseline HBsAg of 100-1000 IU/mL and 100-3000 IU/mL, respectively.
• Favorable Safety and Tolerability
  AHB-137 was well tolerated, throughout treatment and follow-up, with no drug-related serious adverse events and no treatment discontinuations. Most adverse events were mild to moderate and occurred during the dosing phase.

Professor Niu Junqi, principal Investigator and Professor of Hepatology at The First Hospital of Jilin University, commented: "Despite major advances in chronic hepatitis B treatment, achieving a functional cure remains extremely challenging. A functional cure rate of approximately 30% has been widely recognized by global experts as a key milestone for a curative regimen to achieve. AHB-137 is the first investigational therapy to achieve the 30% functional cure rate in a large number of well-defined CHB patients with high unmet medical need. Importantly, Week 72 results suggest that AHB-137 treatment could benefit a broader patient population - not only those achieving functional cure, but also patients who reach very low antigen levels, positioning them as strong responders for subsequent or combination therapies. This progress has the potential to shift the long-standing paradigm of 'control rather than cure,' reducing lifelong treatment burden and long-term risks such as cirrhosis and liver cancer."

Professor Edward J. Gane, renowned hepatologist and Deputy Director of the New Zealand Liver Transplant Unit at Auckland City Hospital, stated, "Sustained off-treatment clearance of circulating hepatitis B surface antigen and HBV DNA after a finite duration of therapy, so-called Functional Cure, is exceptionally difficult to achieve in patients with chronic hepatitis B, which makes these Week 72 monotherapy results with AHB-137 so exciting. The rapid HBsAg decline followed by durable off-treatment control closely reflects the biology required for functional cure. The cure rate observed in this study represents one of the most important advances in HBV therapeutics since the virus was first identified more than 60 years ago."

Dr. Guofeng Cheng, Co-founder and CEO of AusperBio, added: "We are proud to share these milestone results at HEP-DART, a forum that brings together global leading experts in liver diseases. The sustained responses at end of follow-up not only confirm AHB-137's potent antiviral activity but also provide clinical validation of its triple mechanism - targeted reduction of HBsAg at the source, suppression of viral DNA replication, and restoration of immune function. We are accelerating our pivotal clinical programs as we advance toward our mission of transforming treatments for patients with chronic hepatitis B to achieve a functional cure."

About AB-10-8002

AB-10-8002 is a multicenter, randomized, open-label Phase II study evaluating the safety and efficacy of 24-week AHB-137 monotherapy in HBeAg-negative chronic hepatitis B patients who are receiving stable nucleos(t)ide analogue (NA) therapy. Participants received either 225 mg or 300 mg AHB-137 once weekly for 24 weeks, including two loading doses on Days 4 and 11. Following completion of AHB-137 dosing, all patients continued NA therapy for an additional 24 weeks. Eligible participants discontinued NA therapy at Week 48 based on protocol-defined stopping criteria and were followed through Week 72.

About AHB-137

AHB-137 is a novel unconjugated antisense oligonucleotide (ASO) designed using AusperBio's proprietary Med-Oligo™ ASO technology platform and is designed to achieve functional cure in chronic hepatitis B. Its mechanism integrates three complementary actions: targeted suppression of HBsAg at the transcriptional level, inhibition of viral DNA replication, and immune reactivation. AHB-137 has demonstrated promising preclinical and clinical results, with key findings presented at major international hepatology congresses including EASL (2023 - 2025), AASLD (2024 - 2025), and APASL (2025). AHB-137 has completed a global Phase I study and is currently being evaluated in multiple Phase II studies and a phase III trial in China. Supported by a coordinated global development strategy, AHB-137 is advancing toward its goal of delivering a potential functional cure for HBV infection.

About AusperBio.

AusperBio is a clinical-stage biopharmaceutical company with operations in the USA and China, dedicated to advancing oligonucleotide and targeted delivery technologies for transformative therapies, with an initial focus on achieving functional cure for chronic hepatitis B infection. The company has developed a proprietary Med-Oligo™ ASO platform which has been shown to substantially enhance the current ASO therapeutics, through novel insights into ASO design. Combining efficient targeted delivery conjugation technologies, the modular Med-Oligo™ Platform empowers ASO therapeutics to treat a broad range of diseases, including viral infections, metabolic conditions, genetic disorders, and immune diseases. For more information, visit www.ausperbio.com

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SOURCE AusperBio Therapeutics Inc.