Arrowhead announces topline results from ARO-C3 trial

Arrowhead (ARWR) announced topline results from Part 2 of a Phase 1/2 clinical study of ARO-C3, the company’s investigational RNA interference therapeutic designed to reduce liver production of complement component 3 as a potential therapy for various complement mediated diseases. The company plans to present additional results at a medical meeting in 2025. Patients with IgA nephropathy received subcutaneous doses of ARO-C3 on Days 1, 29, and 113 and were followed through Day 169. Maximum mean reduction in C3 of 89% and mean sustained reduction of greater than 87% from baseline through week 24. Maximum mean reduction in serum AH50 of 85% and mean sustained reduction greater than 76% from baseline through week 24. Maximum mean reduction in Wieslab AP of 100% and mean sustained reduction greater than 89% from baseline through week 24. Duration of effect supportive of once every three month or less frequent subcutaneous dosing in later stage studies. Mean reduction in spot UPCR of 41% and maximum individual reduction of 89% from baseline by week 24. ARO-C3 was generally well-tolerated in patients with IgAN. No serious or severe treatment emergent adverse events and no TEAEs that led to study or study drug discontinuation. The only TEAEs reported in more than 1 subject were headache, cough, and nasopharyngitis. No infections with encapsulated organisms.