ClearB Therapeutics, Inc., a clinical-stage biotechnology company committed to developing therapies to drive functional cure in patients with chronic hepatitis B (CHB) infection, announced that review of the safety data from the sentinel subject supported enrollment for the remainder of the cohort in their Phase 1b clinical study evaluating the therapeutic vaccine CLB-4000 (ACTRN12625000250437 and ACTRN12625000204448).

CLB-4000 is a bivalent subunit therapeutic vaccine comprised of CLB-405 and CLB-505 proteins, adjuvanted with TQL-1055. CLB-405 and CLB-505 are variants of HBsAg designed to over-represent clearance profile epitopes identified from functional cure patients. TQL-1055 is a novel, rationally designed, semi-synthetic saponin adjuvant licensed from Adjuvance Technologies, Inc. The CLB-4000-1-001 Phase 1b is an open label multicenter, multiple-dose study designed to assess the safety and tolerability of repeated intramuscular (IM) administration of CLB-4000 (fixed antigen amounts of 250 μg CLB-405 and 250 μg CLB-505, adjuvanted with multiple dose levels of TQL-1055), in noncirrhotic adults with CHB taking a stable dose of a standard of care NUC for viral suppression. To further boost the immune and antiviral responses, additional cohorts will evaluate CLB-4000 with Peg-IFNα-2a. The objectives of the study are safety and tolerability of CLB-4000 with or without Peg-IFNα-2a. Additional objectives include evaluation of antiviral activities and immunological responses. Results are expected on a rolling basis starting 2H 2026.

“It is very exciting to evaluate our promising therapeutic vaccine, CLB-4000 in first in human trials in CHB patients. We look forward to sharing emerging clinical data with the Hepatitis B community as it becomes available” said Aileen Rubio, PhD, CEO for the company. “CHB infection remains a substantial global health care problem with a continued need for safe and effective therapies. We believe that CLB-4000 could become an important component of evolving CHB treatment regimens.”

About Hepatitis B

The World Health Organization defines hepatitis B as a “potentially life-threatening liver infection caused by Hepatitis B virus (HBV). It is a major global health problem. It can cause chronic infection and puts people at high risk of death from cirrhosis and liver cancer.” Approximately 2 billion people are infected with HBV and ~250 million living with CHB. Viral hepatitis is the 7^th ranked cause of human death and liver cancer is the 3^rd most common cause of cancer related death globally.

About ClearB Therapeutics

ClearB Therapeutics was co-founded in 2017 with Professor Stephen Locarnini and the Victoria Infectious Diseases Reference Laboratory in Melbourne, Australia. ClearB is working to develop immune based therapies designed to drive functional cure of hepatitis B infection. The work is grounded in proprietary insights derived from rare-event infection resolution in patients who suffer from CHB. For more information, please visit https://clearbtherapeutics.com/.

About TQL-1055

TQL-1055 is a rationally designed, semi-synthetic analogue of the QS-21 saponin adjuvant which is used in the currently available shingles vaccine. Saponin adjuvants are potent immune stimulators and important components of licensed, currently marketed, and clinically-advanced infectious disease vaccines. The usefulness of saponin adjuvants has been constrained by dose-limiting tolerability and manufacturing challenges. TQL-1055 is designed to have improved tolerability and to provide the same strong immune response as QS-21 and has shown favorable tolerability in a Phase 1 clinical trial.

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