Hepatitis B Immunotherapy Announces Topline Interim Results of Phase 2 Study

An international biotechnology company, Brii Biosciences Limited (Brii Bio), announced on Wednesday its topline cohort-level unblinded week 24 and week 36 data from interim analysis of a randomized, placebo-controlled and double-blinded phase 2 study of its immunotherapeutic candidate, BRII-179 (VBI-2601).

According to the company, the cohort level unblinded data demonstrated that in the intent to treat analysis at week 24 (end of treatment or EoT), 26.3% (15 patients) treated with BRII-179/pegylated interferon-alpha (PEG-IFNα) achieved HBsAg loss compared to 19.3% (11 patients) with placebo/PEG-IFNα.

At week 36 (12 weeks follow-up), 24.6% (14 patients) treated with BRII-179/PEG-IFNα had HBsAg loss, compared with 14.0% (8 patients) with placebo/PEG-IFNα. In the per protocol analysis at Week 24, 32.6% (15 patients) treated with BRII-179/PEG-IFNα achieved HBsAg loss compared to 21.6% (11 patients) with placebo/PEG-IFNα; at Week 36, 31.8% (14 patients) and 14.9% (7 patients) had HBsAg loss, respectively. In addition, 9 out of 15 patients in the cohort treated with BRII-179/PEG-IFNα achieved HBsAg seroconversion at EoT (Week 24), versus 1 out of 11 in the cohort treated with PEG-IFNα alone.

“We are excited by the data from this proof-of-concept study consistent with our previous proof-of-mechanism studies that BRII-179 induces functional immune responses complementing other curative treatment modalities such as PEG-IFNα,” Brii Bio CMO David Margolis, MD, said in a statement. “We look forward to continuing the evaluation of this first-in-class immunotherapeutic candidate through our ongoing and future studies as we work to deliver the highest HBV functional cure rates to the 290 million people around the world living with HBV.”

About the Therapy

BRII-179 is a novel, first-in-class Pre-S1/Pre-S2/S therapeutic vaccine, in combination treatment with PEG-IFNα in patients with chronic hepatitis B (CHB) compared with PEG-IFNα only treatment. The company reported in previous studies that BRII-179 induced broad antibody and T-cell responses against Pre-S1, Pre-S2 and S epitopes in CHB patients.

BRII-179 is currently being investigated in two phase 2 clinical trials in combination with BRII-835 (VIR-2218) and PEG-IFNα as part of a potential functional cure regimen for the treatment of chronic HBV infection.

In addition, the company launched a separate phase 2 HBV study evaluating BRII-835 + PEG-IFNα versus PEG-IFNα active control arm, aims to clarify the additional functional cure efficacy of the combination. The company intends to include patients in the APAC region who were previously exposed to BRII-179 in the phase 2 study. The company believes that BRII-179 has the unique ability to distinguish patients who have significant intrinsic humoral immunity versus those who do not.

According to Brii Bio, the BRII-179/PEG-IFNα treatment was generally safe and tolerated, with adverse events similar to those associated with PEG-IFNα treatment or BRII-179 as previously reported.

In July, Brii Bio expanded the BRII-179 (VBI-2601) license from VBI Vaccines (Nasdaq: VBIV) to global rights. The company is planning for additional combination studies in the near future to investigate BRII-179 as a primer to enhance antibody responses and enrich patients for potentially curative treatments.