AusperBio raises $120M for hepatitis B trial

AusperBio Therapeutics has raised $120 million in series C funds to advance its lead oligonucleotide therapy for chronic hepatitis B. The Bay Area biotech's candidate, AHB-137, is currently in a late-stage study in China.

RA Capital Management led the financing round. Existing investors HanKang Capital, Qiming Venture Partners, YuanBio Venture Capital and CDH Investments also participated. This latest fundraise follows a $37 million series A in 2024 and a three-part series B across 2024-25 that totaled $186 million.

Clinical progress of AHB-137

The company's lead candidate, AHB-137, is an unconjugated antisense oligonucleotide (ASO). It is designed to suppress production of viral hepatitis B protein, inhibit viral DNA replication and promote immune reactivation.

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. According to the company, the therapy was well tolerated with no drug-related serious adverse events. This data gave Ausper the confidence to initiate the phase 3 study.

"AHB-137 has demonstrated promising clinical activity in patients and has the potential to serve as a backbone therapy for functional cure of CHB," said Ausper’s co-founder and chief scientific officer, Chris Yang, Ph.D.

Financing and platform strategy

CEO and co-founder Guofeng Cheng, Ph.D., stated that the series C "represents an important inflection point for AusperBio as we advance AHB-137 toward potential commercialization while developing next-generation therapies for CHB." He added that the company looks forward to building on this momentum to advance its strategy toward functional cure.

The funds will also support the development of a second chronic hepatitis B candidate, AHB-171. This small interfering RNA (siRNA) therapeutic recently entered the clinic. The company states the liver cell-targeted siRNA is designed to selectively suppress viral gene expression and provide potent and sustained antiviral activity.

AusperBio was founded in 2019 to develop targeted oligonucleotide therapies for chronic disease. According to the company's website, chronic hepatitis B affects nearly 296 million people worldwide. Individuals with the disease rely on long-term antiviral therapy to suppress the virus and prevent liver damage.

Competitive landscape

The field of oligonucleotide treatments for hepatitis B is advancing. GSK has led the way with its therapy bepirovirsen, which was licensed from Ionis Pharmaceuticals. That drug was approved in Japan this week and awaits decisions from other regulators in the coming months.

AusperBio's Chris Yang said the new financing will enable the company to further advance its platforms and build on their potential to generate differentiated targeted oligonucleotide therapies for chronic hepatitis B and other diseases with significant unmet medical needs.

The company's ASO technology acts as custom puzzle pieces that attach to mRNA strands in cells of interest and interfere with the instructions for protein production.