AusperBio Raises $120 Million Series C To Push AHB-137 Through Phase 3 In Chronic Hepatitis B

AusperBio Therapeutics has raised $120 million in a series C round to move its chronic hepatitis B therapy AHB-137 through phase 3 testing and, if successful, toward commercialization. The round was led by RA Capital Management, with existing investors HanKang Capital, Qiming Venture Partners, YuanBio Venture Capital and CDH Investments also participating.

The financing adds to a substantial capital base the company has already assembled. AusperBio previously raised a $37 million series A in 2024 and then completed a three-part series B financing across 2024-25 that brought in a total of $186 million.

Why The Round Matters

AusperBio is using the new money to back both its lead asset and follow-on programs in chronic hepatitis B. AHB-137 is an unconjugated antisense oligonucleotide designed to suppress production of viral hepatitis B protein, inhibit viral DNA replication and promote immune reactivation. The drug is already in a late-stage study in China, which makes this financing less about proving a concept in the lab and more about carrying a lead program through an expensive development stage while preparing for potential commercialization.

That matters because chronic hepatitis B remains a large market with room for differentiated approaches. According to AusperBio’s website, nearly 296 million people worldwide are affected. Current care relies on long-term antiviral therapy intended to suppress the virus and prevent liver damage, leaving developers room to argue for therapies aimed at a functional cure.

The Clinical Backdrop

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 also reported to be well tolerated, with no drug-related serious adverse events. Those results gave AusperBio the confidence to move into phase 3 in China.

The company is also putting some of the series C proceeds behind AHB-171, a liver cell-targeted small interfering RNA therapeutic that recently entered the clinic. AusperBio said the siRNA candidate is designed to selectively suppress viral gene expression and provide potent and sustained antiviral activity.

The broader signal is that investors are still willing to fund hepatitis B companies when the story includes both late-stage data and a platform extension. GSK has already shown regulatory progress for the modality class, with bepirovirsen approved in Japan this week and awaiting decisions from other regulators in the coming months. AusperBio’s pitch is that AHB-137 could become a backbone therapy for functional cure of chronic hepatitis B while giving the company a base from which to build additional oligonucleotide medicines.