Clinical Data The poster titled, "RNA interference (RNAi) with ARC-AAT provides deep and prolonged knockdown of alpha-1 antitrypsin levels in healthy volunteers," publication LB-24 in the late-breaking poster session, describes data from a Phase 1, multi-center, randomized, placebo-controlled, double-blind, single dose-escalation first-in-human study to evaluate the safety, tolerability, pharmacokinetics of ARC-AAT and the effect on circulating alpha-1 antitrypsin (AAT) levels. Key findings from the study include the following: Š Dose-dependent reductions in serum AAT of up to 90% were observed Š Duration of effect indicates that monthly, or less frequent, dosing is likely Š Pharmacokinetic (PK) parameters were linear across dose levels with a constant half-life Š There have been no drop outs due to adverse events (AE), no clinically significant changes in ECGs, DLCO or FEV1, and one serious adverse event (SAE) in a placebo subject Š No clinically significant transaminase (ALT, AST) elevations were reported Š The most frequently reported ARC-AAT related AEs were headache, nausea and rigor (each, 3 events in 36 [8%] subjects) The oral presentation titled, "RNA interference therapeutic ARC-AAT prevents production of Z-alpha1 antitrypsin polymers and reverses liver disease phenotype in PiZ mouse model," publication 124 in the session Parallel 19: Pediatric and Metabolic Liver Diseases: Basic and Translational, describes data from a 33-week study of ARC-AAT in the PiZ mouse model. Key findings from the study include the following: Š Cleared Z-hAAT protein from the cytoplasm and reduced by > 90% in serum Š Prevented and reversed polymer accumulation, with Z-hAAT monomer reduced by 87% and polymer by 42% at week 33 Š Halted accumulation of Z-hAAT globules in the liver, with 61% less in ARC-AAT treated compared to saline controls and 24% less than at baseline Š Improved liver health and prevented further damage based on histopathology improvements compared to baseline and saline controls Š Prevented liver inflammation with fewer inflammatory foci and reduced total area of inflammation Š Prevented liver tumors Š Normalized gene expression associated with liver disease