In normal times, VIR’s HBV data would’ve been a hot topic, but my tweet on the dataset (and the planned use of peg-IFN in the follow-up trial) went almost unnoticed.
The Alnylam ESC+ technology incorporated into VIR-2218 is designed to reduce off-target binding while maintaining on-target activity, which is hypothesized to result in an improved hepatic safety profile. In analyses of the in vitro, in vivo and Phase 1 clinical data, the ESC+ siRNA VIR-2218, when compared to the parent compound ALN-HBV, which is not an ESC+ siRNA, was shown to have:
• Improved in vitro specificity by reducing off-target effects on host messenger RNA;
• Decreased propensity to cause ALT elevations in a humanized liver chimeric mouse model; and
• In a cross-study comparison of Phase 1 data, decreased propensity to cause ALT elevations in healthy volunteers at dose levels anticipated to be clinically relevant.
IYO, is this bona fide differentiation… or mostly spin?