Vir Biotechnology (VIR) Status update summary

ECLIPSE 1 results

• Phase III randomized 124 patients 2:1 to elebsiran 200 mg plus tobevibart 300 mg Q4W (n=83) or delayed treatment (n=41); ~55% had compensated cirrhosis.

• At Week 48, the primary endpoint of HDV RNA TND plus ALT normalization was reached by 44.1% vs 0% (treatment difference 44.1 percentage points; 95% CI 32.6–55.0; p<0.0001).

• HDV RNA TND was reached by 79.2% vs 0%; all treated patients achieved TND or a ≥2-log10 HDV RNA reduction.

• ALT normalized in 53.0% and HBsAg fell below 10 IU/mL in 95.2%; TND rates were 84.8% with compensated cirrhosis and 73.0% without cirrhosis.

Safety and treatment profile

• All treated participants completed 48 weeks without study-drug interruption or discontinuation; no serious or grade 4 adverse events occurred, and one treatment-related grade 3 neutrophil decrease resolved within 15 days.

• Flu-like symptoms were among the more common treatment-emergent events, mostly after the first dose and resolving within 24–48 hours.

• Elebsiran reduces HBsAg production; tobevibart neutralizes circulating virus and blocks HBV/HDV entry into hepatocytes.

SOLSTICE Week 96 results

• All 28 participants who completed 96 weeks of combination therapy had undetectable HDV RNA; 53% of all participants had ALT normalization at Week 96.

• Among participants with paired liver stiffness measurements, 24/27 (89%) had stable or improved readings, with notable reductions among participants with cirrhosis.

• Extended treatment was generally well tolerated; adverse events were mild to moderate, with no study-drug-related discontinuations or serious adverse events.