AusperBio adds $120M series C to advance hep B oligo therapy through phase 3 and beyond

Biotech AusperBio adds $120M series C to advance hep B oligo therapy through phase 3 and beyond By Marissa Russo Aug 28, 2026 10:26am chronic hepatitis B series C antisense AusperBio Therapeutics has raised $120 million in series C funds to advance its oligonucleotide therapy for chronic hepatitis B through phase 3 testing and hopefully on to commercialization. The Bay Area biotech's lead candidate, dubbed AHB-137, is an unconjugated antisense oligonucleotide (ASO) designed to suppress production of viral hepatitis B protein, inhibit viral DNA replication and promote immune reactivation. The therapy is currently undergoing a late-stage study in China.

The series C was led by RA Capital Management, alongside existing investors like HanKang Capital, Qiming Venture Partners, YuanBio Venture Capital and CDH Investments. It follows a $37 million series A in 2024 and a three-part series B financing across 2024-25 that brought in a total of $186 million. Ausper CEO and co-founder Guofeng Cheng, Ph.D., said the latest fundraise “represents an important inflection point for AusperBio as we advance AHB-137 toward potential commercialization while developing next-generation therapies for CHB.” “We look forward to building on this momentum to advance our strategy toward functional cure and unlock new opportunities across our oligonucleotide platforms,” the CEO added.

The Bay Area biotech was founded in 2019 to develop targeted oligonucleotide therapies for chronic disease. Chronic hepatitis B, caused by the hepatitis B virus, affects nearly 296 million people worldwide, according to AusperBio’s website. Individuals living with this disease rely on long-term antiviral therapy in attempts to suppress the virus and prevent liver damage.

ASOs act as custom puzzle pieces that attach to mRNA strands in cells of interest and interfere with the instructions for protein production. In a recently completed phase 2a study, AHB-137 monotherapy achieved a 30% functional cure rate at week 72 in patients with chronic hepatitis B. The therapy was also well tolerated with no drug-related serious adverse events, giving Ausper the confidence to take the drug into the phase 3 study in China.

“AHB-137 has demonstrated promising clinical activity in patients and has the potential to serve as a backbone therapy for functional cure of CHB,” Ausper’s co-founder and chief scientific officer, Chris Yang, Ph.D., said. “This financing will enable us to further advance these platforms and build on their potential to generate differentiated targeted oligonucleotide therapies for CHB and other diseases with significant unmet medical needs.” GSK has led the way when it comes to using an oligonucleotide to treat chronic hepatitis B. The pharma's therapy bepirovirsen—which was licensed from Ionis Pharmaceuticals—was approved in Japan this week and is awaiting a decision from other regulators in the coming months.

Ausper's funds will also help with the development of another potential chronic hepatitis B treatment in the form of AHB-171. The small interfering RNA (siRNA) therapeutic recently entered the clinic. The liver cell-targeted siRNA is designed to selectively suppress viral gene expression and provide potent and sustained antiviral activity, according to the company.

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