Brii Biosciences and VBI Vaccines ’ Hepatitis B virus (HBV) therapy BRII-179 bettered its chances of moving to the next phase of development with a 11-point jump in its Phase Transition Success Rate (PTSR) after positive Phase Ib/IIa results. The PTSR, which is the probability, given as a percentage, of a drug progressing successfully from one development stage to the next, was updated on 25 June.

The Phase Ib/IIa study (ACTRN12619001210167) showed that BRII-179 alone or with interferon-alpha, which acts as a coadjuvant, induced B-cell and T-cell responses in patients with chronic Hepatitis B, as per a 23 June press release. The data was presented at the virtual European Association of the Study of the Liver meeting last week. BRII-179 is also currently in a Phase II trial (NCT04749368) in combination with BRII-835, a small interfering ribonucleic acid (siRNA) targeting HBV.

Durham, North Carolina-headquartered Brii licensed the commercial rights to BRII-179 from VBI Vaccines in December 2018 covering China, Hong Kong, Macau, and Taiwan. Brii is collaborating with VBI and Vir Biotechnology  to run the Phase Ib/IIa study.

In the Phase II trial, patients receive BRII-179 monotherapy, the BRII-179/BRII-835 combination, or the combination plus interferon-alpha. The addition of interferon-alpha, and enlargement of the BRII-179/BRII-835 cohort from 32 to 40 patients was done recently, as per a 21 June update on its ClinicalTrials.gov entry. While the Phase II study’s primary endpoint was earlier designed to measure the percentage of patients withdrawing from nucleoside reverse transcriptase inhibitors (NrtI), it was also changed to sustained Hepatitis B surface antigen loss during the 48-week period after NrtI withdrawal. Other primary outcomes in the trial are focused on safety and tolerability.

VBI has a $1.01bn market cap.

William Newton is a Healthcare Reporter for Clinical Trials Arena parent company GlobalData’s investigative journalism team. A version of this article originally appeared on the Insights module of GlobalData’s Pharmaceutical Intelligence Center. To access more articles like this, visit GlobalData.