The primary objective of the study is to evaluate the safety and tolerability of single intravenous (IV) doses of REGN5381 in healthy normotensive and otherwise healthy hypertensive adults.

The secondary objectives of the study are:

• To evaluate the effect of single IV doses of REGN5381 on blood pressure (BP) and heart rate (HR) in healthy normotensive and otherwise healthy hypertensive adults
• To evaluate the effect of single IV doses of REGN5381 on cardiac stroke volume (SV)
• To evaluate the pharmacokinetics (PK) of single IV doses of REGN5381
• To evaluate the immunogenicity of single IV doses of REGN5381

Inclusion Criteria:

1. Normal or mildly elevated blood pressure as defined in the protocol

Exclusion Criteria:

1. History of cardiovascular disease as defined in the protocol
2. Protocol-defined risk factors for cardiovascular disease
3. History of unexplained syncope, autonomic dysfunction, or neurologic disease.

NOTE: Additional Inclusion / Exclusion criteria apply

All Individual Patient Data (IPD) that underlie publicly available results will be considered for sharing

Individual anonymized participant data will be considered for sharing once the indication has been approved by a regulatory body, if there is legal authority to share the data and there is not a reasonable likelihood of participant re-identification.

Qualified researchers may request access to anonymized patient level data or aggregate study data when Regeneron has received marketing authorization from major health authorities (e.g., Food and Drug Administration (FDA), European Medicines Agency (EMA), Pharmaceuticals and Medical Devices Agency (PMDA), etc) for the product and indication, has the legal authority to share the data, and has made the study results publicly available (eg, scientific publication, scientific conference, clinical trial registry).