Benzinga | Sep 16, 2020 07:35AM EDT

Arrowhead Announces ARO-AAT Phase 2 Interim Results

- Up to 97% reduction in intra-hepatic Z-AAT polymer

- Up to 95% reduction in intra-hepatic total Z-AAT burden

- Up to 66% and 58% reduction in circulating ALT and GGT levels respectively

- Up to 26% improvement in FibroScan values

Arrowhead Pharmaceuticals Inc. (NASDAQ:ARWR) today announced positive interim 24-week liver biopsy results in four subjects from AROAAT2002, an open-label Phase 2 clinical study of ARO-AAT, the company's second generation investigational RNA interference (RNAi) therapeutic being developed as a treatment for the rare genetic liver disease associated with alpha-1 antitrypsin deficiency (AATD). The results show clear evidence of a meaningful pharmacodynamic effect by ARO-AAT, leading to improvements in relevant biomarkers, including substantial reductions in intra-hepatic mutant AAT protein (Z-AAT), both Z-AAT monomer and Z-AAT polymer; improvements in liver stiffness based on FibroScan; and, a decrease in alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT), both serum biomarkers of liver injury.

After 24 weeks of treatment with investigational ARO-AAT in the AROAAT2002 study, serum and total intra-hepatic Z-AAT decreased in all four patients by up to 93% and 95%, respectively. Three of four patients demonstrated reductions from baseline in intra-hepatic Z-AAT polymer, with a maximum reduction of 97%. All four patients showed reductions in ALT and GGT, with maximum reductions of 66% and 58%, respectively. All patients demonstrated improved transient elastography FibroScan values, with three of four patients exhibiting greater than 20% reductions.