This was a double blind, randomized, placebo controlled, single and multiple IV dose study conducted in 2 parts, single ascending dose and multiple ascending doses parts. The principal aim of this study was to obtain safety and tolerability data when PA-001 is administered IV as single and multiple doses to healthy subjects. This information, together with the PK data, will help establish the doses and dosing regimen suitable for future studies in patients. The study also investigated the effects of age on the PK of PA-001 prior to patient studies.

Inclusion Criteria:

• Groups of healthy subjects: Males or females, of any race, between 18 and 65 years of age, inclusive.
• Group(s) of elderly subjects: Males or females, of any race, > 65 years of age.
• Body mass index between 18.0 and 32.0 kg/m2, inclusive.
• In good health, or have stable, chronic, non life threatening medical conditions, determined by no clinically significant findings
• Females will not be pregnant or lactating, and females of childbearing potential and males will agree to use contraception.
• Able to comprehend and willing to sign an ICF and to abide by the study restrictions.

Exclusion Criteria:

• Significant history or clinical manifestation of any metabolic, allergic, dermatological, hepatic, renal, hematological, pulmonary, cardiovascular, gastrointestinal, neurological, respiratory, endocrine, or psychiatric disorder that, in the opinion of the investigator (or designee), could impact subject safety or the objectives of the study.
• Have signs and symptoms of any other liver disease, except nonalcoholic fatty liver disease, or any of the following, as determined from clinical laboratory evaluations:
• History of significant hypersensitivity, intolerance, or allergy to any drug compound, food, or other substance, as determined by the investigator (or designee).
• Positive hepatitis panel or positive human immunodeficiency virus test.
• Positive SARS-CoV-2 test at screening or check in.
• Have signs which shows something was not right in the ECG or history of additional risk factors for torsades de pointes.
• Administration of a COVID 19 vaccine in the past 30 days prior to dosing.
• Participation in a clinical study involving administration of an investigational drug (new chemical entity) in the past 30 days or 5 half lives of that drug prior to dosing, whichever is longer.
• Subjects who, in the opinion of the investigator (or designee), should not participate in this study.