FDA grants orphan drug status for Arrowhead’s ARC-AAT to treat liver disease

AATD is a rare genetic disease that severely damages the liver and lungs of affected children and adults.

Currently, the company is conducting part B of a Phase I trial of ARC-AAT in patients with PiZZ genotype AATD.

Arrowhead chief operating officer Bruce Given said: "Receiving orphan drug designation is an important milestone in the development of ARC-AAT, which we think is a very promising program aimed at providing a better option for patients with liver disease associated with alpha-1 antitrypsin deficiency.

"The Orphan Drug Act provides important incentives for sponsors to develop drugs that treat rare diseases and we look forward to more engagement with the FDA as the development of ARC-AAT progresses."

The ongoing multi-center, randomized, placebo-controlled, double-blind, single dose-escalation first-in-human Phase I trial is designed to evaluate the safety, tolerability and pharmacokinetics of ARC-AAT and the effect on circulating AAT levels.

The trial has been enrolling in dose groups of six participants each, with participants randomized at a ratio of 2:1 to receive a single intravenous injection of either ARC-AAT or placebo (normal saline).

The trial includes two parts Part A in healthy volunteers has been completed, while Part B is to be conducted in patients with PiZZ genotype AATD.

All trial participants will be evaluated for 28 days following dosing, with additional follow-up if needed every two weeks until AAT levels return to baseline.