Study of Natriuretic Peptide Receptor 1 (NPR1) Antagonist in Adult Patients With Postural Orthostatic Tachycardia Syndrome (POTS)

This study is researching an experimental drug called REGN7544 (called "study drug"). The study is focused on participants with POTS. The aim of the study is to see how safe, tolerable, and effective the study drug is. The study is looking at several other research questions, including: * How the study drug changes heart rate and blood pressure in participants with POTS * What side effects may happen from taking the study drug * How much study drug is in the blood at different times * Whether the body makes antibodies against the study drug (which could make the study drug less effective or could lead to side effects) * How the study drug affects symptoms associated with POTS

Key Inclusion Criteria: 1. Is diagnosed with POTS and demonstrates consensus criteria (a), (b), (c) and (d) below during screening: 1. Increase in HR ≥30 Beats Per Minute (BPM) within 10 minutes of changing from supine to a standing position, as described in the protocol 2. Absence of orthostatic hypotension, defined as a decrease in Systolic Blood Pressure (SBP) \>20 mm Hg within 3 minutes of standing 3. Absence of other conditions explaining orthostatic tachycardia in the judgment of the investigator, as defined in the protocol 4. Ongoing episodic symptoms consistent with POTS (for example, lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, and fatigue) that are worse with standing and are relieved by lying down and which have been present for ≥3 months 2. During screening, a participant must score ≥3 on the Patient Global Impressions of Severity (PGIS) 3. Has a body mass index between 18 and 35 kg/m2, inclusive Key Exclusion Criteria: 1. History of hypertension or a seated SBP during screening that is \>140 mm Hg 2. SBP during Active Stand (AS) test during screening, either supine or standing, that is \>140 mm Hg systolic on ≥2 measurements 3. Increase in HR \