This study will be conducted to evaluate the safety, tolerability, activity, pharmacokinetics, and pharmacodynamics of NTLA-2002 in adults with Hereditary Angioedema (HAE).

Inclusion Criteria:

1. Age >18 years
2. Diagnosis of HAE Types I or II
3. Ability to provide evidence of HAE attacks to meet the screening requirement
4. Subjects must have access to, and the ability to use, ≥ 1 acute medication(s) to treat angioedema attacks.
5. Adequate chemistry and hematology measures at screening
6. Subjects must agree not to participate in another interventional study for the duration of this trial.
7. Subjects must be capable of providing signed informed consent

Exclusion Criteria:

1. Concurrent diagnosis of any other type of recurrent angioedema
2. Subjects who have known negative reaction or hypersensitivity to any lipid nanoparticles (LNP) component.
3. Any condition that, in the Investigator's opinion, could adversely affect the safety of the subject.
4. Unwilling to comply with study procedures.

Phase 1 is an open label non-randomized study Phase 2 is a randomized, double-blind, placebo-controlled study