Arrowhead's ARO-C3 cut C3 levels by up to 89% and proteinuria by 41% in a Phase 1/2 trial. Additional results will be presented at a 2025 medical meeting.

Arrowhead’s stock has dropped slightly since market open, slipping 4.3% from $16.56 per share to $16.28 as of 10:30 a.m. The decline came amid a market-wide selloff on Monday.