ClearB Therapeutics has announced that it will present new preclinical data on its therapeutic vaccine candidate for chronic hepatitis B at the upcoming European Association for the Study of the Liver (EASL) International Liver Congress 2025. The event will take place in Amsterdam, Netherlands, from May 7-10, 2025.
The company will showcase findings demonstrating that naïve C57BL/6 mice immunized with their HBsAg variants, CLB-405 and CLB-505, combined with a saponin-based adjuvant called TQL-1055, exhibited dose-dependent humoral and cellular immune responses. This data represents a significant step forward in the company's efforts to develop therapeutic vaccines designed to drive a functional cure for hepatitis B.
"We are excited to share preclinical data on our therapeutic vaccine candidate, CLB-4000, with the Hepatitis B community," said Aileen Rubio, PhD, CEO of ClearB Therapeutics. "Chronic Hepatitis B infection remains a substantial global health care problem in need of effective antiviral and immunomodulatory therapies. We continue to believe that the functional cure insights translated into the HBsAg variants, CLB-405 and CLB-505, will greatly benefit from the unique adjuvant properties of TQL-1055 and could become an important component of treatment regimens."
The Global Burden of Chronic Hepatitis B
Chronic hepatitis B (CHB) affects approximately 296 million people worldwide, according to the World Health Organization. The infection can lead to serious liver complications, including cirrhosis and hepatocellular carcinoma, resulting in approximately 820,000 deaths annually. Current standard-of-care treatments primarily suppress viral replication but rarely achieve functional cure, defined as sustained loss of hepatitis B surface antigen (HBsAg) with or without seroconversion.
The development of therapeutic vaccines represents a promising approach to address this unmet medical need by stimulating the immune system to recognize and clear the virus, potentially leading to functional cure in chronically infected patients.
The Science Behind CLB-4000
ClearB's therapeutic vaccine candidate, CLB-4000, incorporates HBsAg variants CLB-405 and CLB-505, which are designed based on proprietary insights derived from studying rare-event infection resolution in patients with chronic hepatitis B. These variants are combined with TQL-1055, a novel adjuvant with improved tolerability compared to traditional saponin adjuvants.
TQL-1055 is a rationally designed, semi-synthetic analogue of the QS-21 saponin adjuvant, which is currently used in the shingles vaccine. While saponin adjuvants are potent immune stimulators and important components of many vaccines, their usefulness has historically been constrained by dose-limiting tolerability and manufacturing challenges. TQL-1055 aims to overcome these limitations while maintaining strong immunostimulatory properties.
The poster presentation at EASL will provide detailed data on how this combination elicits both humoral (antibody-mediated) and cellular immune responses in preclinical models, which are both critical components for achieving functional cure in chronic hepatitis B.
Presentation Details
The abstract (number 2965) will be presented as poster FRI-230 on Friday, May 9, 2025, at 8:30 AM GMT+1. Dr. Aditi Deshpande from ClearB Therapeutics will present the findings titled "Naïve C57BL/6 mice immunized with CLB-405 and CLB-505 combined with a saponin-based adjuvant, TQL-1055, exhibit a dose-dependent humoral and cellular immune response."
About ClearB Therapeutics
ClearB Therapeutics was co-founded in 2017 by Morningside Ventures in collaboration with Professor Stephen Locarnini and the Victoria Infectious Diseases Reference Laboratory in Melbourne, Australia. The company's work is grounded in proprietary insights derived from studying rare-event infection resolution in patients who suffer from chronic hepatitis B.
The company's approach differs from traditional antiviral therapies by focusing on immunomodulation to stimulate the body's own immune system to clear the virus. This strategy aligns with the growing consensus in the field that achieving functional cure for chronic hepatitis B will likely require combination approaches that both suppress viral replication and restore immune function.
Phase 1 clinical trials have already shown favorable tolerability for the TQL-1055 adjuvant, an important milestone in the development pathway. The preclinical data to be presented at EASL represents another critical step toward potential clinical studies of the complete therapeutic vaccine candidate.
As the hepatitis B treatment landscape continues to evolve, therapeutic vaccines like CLB-4000 could potentially become key components of future combination regimens aimed at achieving functional cure, addressing one of the most persistent global infectious disease challenges.
