作者
Mark K. Schlegel,Maja M. Janas,Yongfeng Jiang,Joseph D. Barry,Wendell Davis,Saket Agarwal,Daniel Berman,Christopher R. Brown,Adam Castoreno,Sarah LeBlanc,Abigail Liebow,Tara Mayo,Stuart Milstein,Tuyen Nguyen,Svetlana Shulga-Morskaya,Sarah Hyde,Sally Schofield,John Szeto,Lauren Blair Woods,Vedat O. Yilmaz,Muthiah Manoharan,Martin Egli,Klaus Charissé,Laura Sepp‐Lorenzino,Patrick Haslett,Kevin Fitzgerald,Vasant Jadhav,Martin A. Maier
摘要
Preclinical mechanistic studies have pointed towards RNA interference-mediated off-target effects as a major driver of hepatotoxicity for GalNAc-siRNA conjugates. Here, we demonstrate that a single glycol nucleic acid or 2'-5'-RNA modification can substantially reduce small interfering RNA (siRNA) seed-mediated binding to off-target transcripts while maintaining on-target activity. In siRNAs with established hepatotoxicity driven by off-target effects, these novel designs with seed-pairing destabilization, termed enhanced stabilization chemistry plus (ESC+), demonstrated a substantially improved therapeutic window in rats. In contrast, siRNAs thermally destabilized to a similar extent by the incorporation of multiple DNA nucleotides in the seed region showed little to no improvement in rat safety suggesting that factors in addition to global thermodynamics play a role in off-target mitigation. We utilized the ESC+ strategy to improve the safety of ALN-HBV, which exhibited dose-dependent, transient and asymptomatic alanine aminotransferase elevations in healthy volunteers. The redesigned ALN-HBV02 (VIR-2218) showed improved specificity with comparable on-target activity and the program was reintroduced into clinical development.