Vir offers positive update on hepatitis delta treatments

Vir Biotechnology's recent follow-up data reveals promising outcomes for chronic hepatitis delta treatment using a combination of tobevibart and elebsiran. The Phase II SOLSTICE trial data, presented at the European Association for the Study of the Liver (EASL) congress, demonstrated a 100% success rate in keeping patients virus-free and improving liver function, specifically through the rate of ALT normalization.

In the study, 27 patients exhibited a 100% virologic response rate at week 12, and this response rate was sustained in 11 participants who completed the study through week 24. Additionally, ALT normalization rates for these two groups were 44% and 64% at the corresponding timepoints. These figures align with expectations from Barclays analysts, who anticipated a maintained viral response rate of around 100% and a steadily improving ALT normalization rate approaching 60%.

Further analysis revealed that tobevibart monotherapy also yielded encouraging results. At the 12-week mark, 73% of patients showed a virologic response, which slightly decreased to 55% at 24 weeks. The ALT normalization rate in this group increased from 54% at 12 weeks to 64% after 24 weeks. Marianne De Backer, CEO of Vir Biotechnology, remarked that the preliminary data strongly suggests that either the combination of tobevibart and elebsiran or tobevibart alone could offer a transformative treatment option for chronic hepatitis delta.

Previously, five participants receiving the combination therapy had shown a virologic response at week 12. The latest data presented at EASL continues to show a sustained virologic response for all five patients at week 48. Vir is on track to provide additional 24-week treatment data for all 60 participants in the SOLSTICE trial during the fourth quarter.

Tobevibart, also known as VIR-3434, is a monoclonal antibody that prevents hepatitis delta viruses from entering hepatocytes. Elebsiran, formerly known as VIR-2218, is a small interfering RNA that degrades hepatitis B virus RNA transcripts, thereby limiting the production of hepatitis B surface antigen. This treatment approach stems from Vir's collaboration with Alnylam Pharmaceuticals.

Vir Biotechnology is banking on the success of tobevibart and elebsiran, their lead assets, to regain momentum after a previous setback. The company had faced challenges with its influenza A therapy, VIR-2482, which did not meet expectations in the Phase II PENINSULA trial last year. This failure led to cost reductions, including a 12% workforce layoff, and a shift in focus towards their chronic hepatitis delta and chronic hepatitis B programs.