Viral Hepatitis: VIR emphasizes upcoming HBV and HDV readouts at AASLD

VIR hosted a live earnings call on November 2^nd, 2023, and posted a press release, uploaded a new corporate presentation, and released an SEC Form 8-K on their investor relations page. 

Key Highlights:

• VIR continues to communicate previously stated timelines and catalysts in HBV Cure and HDV and demonstrates clear confidence and excitement about the potential of VIR-2218 (siRNA) and VIR-3434 (mAb) in HDV and HBV.
• HDV: Initial data from the Ph2 SOLSTICE trial (N=118) evaluating VIR-2218 (siRNA) + VIR-3434 (mAb) will be presented at AASLD 2023 as a late-breaking oral presentation; additional clinical data is expected in Q2 2024
  • Presentation at AASLD will include data from “small cohorts” of siRNA monotherapy treated patients, mAb monotherapy treated patients, and combination siRNA + mAb treated patients after a short treatment duration
• HBVCure: 24-wk on-treatment data from the Ph2 Part B MARCH trial (N=415) testing combination VIR-3434 (mAb) ± VIR-2218 (siRNA) ± Peg-IFNα will be presented at AASLD 2023 as a late-breaking poster presentation; 6-month post-treatment functional cure endpoint data is expected in Q2 2024
  • Leadership noted difficulties in predicting off-treatment success based on on-treatment data in HBV, and acknowledged the “clinical bar” of 30% or higher rates of functional cure to move forward with late-stage trials and regulatory approval

Assessment:

• Early data from the Ph2 SOLSTICE trial will provide the first look at the potential of the regimen as a chronic treatment.
  • Concerning safety signals relating to ALT elevations from the JNJ-3989 (siRNA) study presented at EASL 2023 indicate that VIR’s siRNA may face a challenging development and regulatory path
  • If VIR continues to develop the VIR-2218 + VIR-3434 in HDV, an approval in mid 2030 would be possible following the successful completion of a pivotal Ph3 study
• Anticipated 24-wk on-treatment data from the Ph2 MARCH trial evaluating VIR-2218 (siRNA) + VIR-3434 (mAb) + peg-IFN will provide some understanding of the combination’s therapeutic potential; however, off-treatment data will need to be seen to assess the combination’s ability to achieve functional cure
  • VIR-2218 and VIR-3434 both aim to supress HBsAg levels so on-treatment HBsAg negativity may indicate transient antigen suppression rather than functional cure; recall, many patients rebounded during off-treatment follow-up for VIR-2218 + peg-IFN (16.1% SVR24) and GSK’s bepirovirsen monotherapy ( ~9% SVR24)