
Shares of gene-editing firm Intellia Therapeutics NTLA.O down 60% to $61.02 premarket
Co pauses patient dosing in late-stage trials of its experimental gene-editing treatment called nex-z in a type of protein buildup disease
NTLA says pause follows severe liver side effects in one patient dosed in late-stage trial
Co consulting experts and regulators on next steps - NTLA
Over 450 patients estimated to have received nex-z so far, Co said
Up to last close, stock down 120% YTD