Sequence-specific, hTLR8-dependent innate immune activity; no activity at other pattern recognition receptors
“In nonclinical studies, bepirovirsen exhibited innate immune activity in a sequence-specific, human toll-like receptor 8 (hTLR8)-dependent manner, with no activity observed at other pattern recognition receptors tested.”
Detected in mouse milk (LD 10) with negligible systemic exposure in offspring; tissue distribution not stated
“Although bepirovirsen was detected in the milk of lactating mice (on LD 10), systemic exposure of bepirovirsen in the offspring via milk was negligible.”
Phosphorothioate ASO class effect: increased tumors in 2-year subcutaneous mouse carcinogenicity studies; clinical relevance unknown
“Increased tumor findings have been observed in 2-year carcinogenicity studies in mice dosed subcutaneously with phosphorothioate ASO class drugs; the clinical relevance is unknown.”
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Anti-drug antibodies: patients
43% (517/1,203) ADA positive in Phase 3 B-Well trials; ADAs lowered clearance by 26.6%
“In the Phase 3 B-Well trials, 43% (517/1,203) of participants treated with HIBSAGO tested positive for ADAs. The presence of ADAs resulted in a 26.6% lower systemic clearance of bepirovirsen.”
Main pharmacology-related risk is increased susceptibility to infections (C5 inhibition); no complement activation by the aptamer in monkeys; panuveitis with Lucentis combination