Barinthus Shares Results From Phase 2b HBV003 Clinical Trial

Barinthus Biotherapeutics has released pivotal findings from its Phase 2b HBV003 clinical trial. The will be presented by Dr. Chun-Jen Liu on November 18, 2024, at 5:30 PM PT during the American Association for the Study of Liver Diseases (AASLD) Liver Meeting® 2024. The company, known for its innovative immunotherapy treatments, is evaluating the efficacy of VTP-300 combined with low-dose nivolumab, an anti-PD-1 monoclonal antibody, in addressing chronic hepatitis B.

The trial, fully enrolled with 121 participants, includes 69 individuals with HBsAg levels under 200 IU/mL. As of the latest data cut-off, eight participants achieved complete HBsAg loss (levels below 0.05 IU/mL), with two meeting the criteria for a functional cure. Remarkably, two participants also developed anti-hepatitis B antibodies, including one achieving a functional cure. Preliminary results suggest enhanced responses in groups receiving the combination therapy.

Dr. Chun-Jen Liu, an investigator on HBV003 and Director of the Hepatitis Research Center and Clinical Trial Center at National Taiwan University Hospital, Taiwan, said, “Sustained HBsAg loss has proven to be the largest hurdle in getting chronic hepatitis B patients to functional cure. The data we see with VTP-300 is unique because they indicate a durable loss of HBsAg in participants, including two who met the criteria for functional cure. Although the study is still ongoing, these early data may bring us a step closer to potentially allowing some patients with chronic hepatitis B to come off antiviral treatment without their chronic hepatitis B progressing.”

Critical findings for 40 participants with HBsAg levels below 200 IU/mL at screening who reached Day 169 include:

- 24 eligible for discontinuing NUCs.

- Eight achieved HBsAg loss, two after Day 169.  

- Nine opted to discontinue NUCs, with 66% (6 of 9) remaining off therapy for over six months.  

- Two of these six participants met functional cure criteria, with two showing seroconversion to HBsAb positivity.

- The study has demonstrated durable HBsAg reductions across all treatment groups, aligning with previously presented data at the EASL Congress in June 2024.

- Safety evaluations indicate that the VTP-300 and low-dose nivolumab combination is generally well tolerated, with no treatment-related serious adverse events reported as of the cut-off.

Dr. Nadege Pelletier, Chief Scientific Officer of Barinthus Bio, said in a statement, "These Phase 2 data are incredibly encouraging and highlight the ability of VTP-300 to stimulate the immune response and induce sustained reductions in HBsAg to the point of meeting functional cure criteria. Moreover, the finding that one of the participants meeting functional cure criteria had antibodies against hepatitis B is promising as HBsAb positivity is associated with long-term infection control by the immune system.”

As defined by the AASLD, a functional cure requires sustained HBsAg loss and undetectable HBV DNA for six months off-treatment. Data collection is ongoing for the remaining participants, with follow-up continuing to assess additional outcomes.