A Study of ARC-AAT in Healthy Volunteer Subjects and Patients With Alpha-1 Antitrypsin Deficiency (AATD)

Inclusion Criteria: (Part A - Healthy Volunteers) * Male or female healthy volunteers 18-50 years of age * Written informed consent * Body mass index between 18.0 and 28.0 kg/m2 * 12-lead electrocardiogram (ECG) at Screening and pre-dose assessment with no clinically significant abnormalities * Non-pregnant/non-nursing females * Non-smoker for at least one year with current non-smoking status confirmed by urine cotinine * Normal lung function (or not clinically significant per investigator assessment) based on spirometry and diffusion capacity of lung for carbon monoxide (DLCO) according to American Thoracic Society (ATS) - European Respiratory Society (ERS) criteria * Highly effective, double barrier contraception (both male and female partners) during the study and for 3 months following the dose of ARC-AAT * Willing and able to comply with all study assessments and adhere to protocol schedule * Suitable venous access for blood sampling * No abnormal finding of clinical relevance at screening * Normal AAT level (Part B-Patients) - As for Part A with the following exceptions: * Male or female patients 18-70 years of age * Confirmed diagnosis of homozygous alpha 1-protease inhibitor deficiency (PiZZ genotype) not receiving alpha-1 antitrypsin augmentation therapy for more than 4 weeks * BMI between 18.0 and 35.0 kg/m2 * Non-smoker for at least three years with current non-smoking status confirmed by urine cotinine Exclusion Criteria: (Part A-Healthy Volunteers) * Curre…