Inclusion Criteria:

1. Males or females 18-80 years of age, inclusive, at the time of screening
2. Diagnosis of AATD
3. Evidence of emphysema secondary to AATD
4. FEV1 of ≥ 30% and ≤ 80% predicted at screening
5. Current non-smoking status.

Exclusion Criteria:

1. Receipt of A1PI augmentation therapy within 5 weeks prior to the first dose of study drug
2. Known or suspected allergy to components of INBRX-101, A1PI or human IgG
3. Known selective or severe Immunoglobulin A (IgA) deficiency
4. Known or suspected diagnosis of type 1 diabetes or diagnosed with uncontrolled type 2 diabetes
5. Received IV immunoglobulins, monoclonal antibodies and/or other biologic therapies within 30 days
6. On waiting list for lung or liver transplant
7. Acute respiratory tract infection or COPD exacerbation within 4 weeks prior to or during screening
8. Evidence of decompensated cirrhosis
9. Active cancers or has a history of malignancy within 5 years prior to screening
10. History of unstable cor pulmonale
11. Clinically significant congestive heart failure