Phase 1, Randomized, Double-Blind, Placebo-Controlled Exploratory Study That Will Assess the Safety, Tolerability, Pharmacokinetics and Hemodynamic Response to a Single 30 Minute Intravenous Infusion of Vasomera™ (PB1046) in Adult Subjects With Stage 1 or 2 Essential Hypertension

The study will be conducted in two parts.

Part 1: For the initial evaluation of safety, pharmacokinetic exposure and pharmacodynamic
response, subjects will be tapered off antihypertensive background therapy.The initial
starting dose will be a sub-therapeutic dose. Dose escalation will continue with a maximum
of a doubling of the previous dose until either 1) a maximum tolerated dose (MTD) is
identified or 2) modeling of the pharmacokinetic (PK) data indicate that maximum exposure
(Cmax) at the next planned dose level would exceed a maximum drug concentration (Cmax) which
was the maximum observed drug concentration following a single subcutaneous administration
in Study PB1046-PT-CL-0001.

Part 2: The dose group which is capable of providing a Cmax exposure which is capable of
eliciting a clinically relevant hemodynamic response, will be expanded to enroll an
additional 12 subjects (6 active and 6 placebo).

Inclusion Criteria:

- Willing and able to sign a written informed consent and follow all study related
procedures.

- Males or females age 18 - 80 years of age inclusive.

- Male and female subjects of childbearing potential must be willing and able to
practice effective contraception during the study, and be willing and able to
continue contraception for 1 month (30 days) after their last dose of study drug.

- BMI ≥ 20 but ≤ 40 kg/m2

- Diagnosed with essential hypertension and are currently taking one or more
antihypertensive medications to control their blood pressure and, who in the opinion
of the investigator, could be safely withdrawn from antihypertensive therapy.

Exclusion Criteria:

- Known allergy to the study drug or any of its components, or who have previously
received Vasomera (PB1046).

- Inadequate "imaging window" by echocardiography as determined by screening
echocardiography (core assessment), or cardiac abnormalities that may confound
echocardiography readings (i.e., mitral regurgitation, "floppy-valve" syndrome) for
evaluation of secondary study endpoints.

- Seated systolic blood pressure <120 mmHg or diastolic blood pressure < 80 mmHg
(confirmed in triplicate) at randomization (Day -1) or prior to the first dose of
study drug (V3 Day 0) will exclude the subject from participation.

- Evidence of sustained elevation in systolic blood pressure >169 mmHg or diastolic
blood pressure >109 mmHg prior to dosing (Day 0) during the washout period which in
the opinion of the investigator would place the subject at risk for continued study
participation (i.e., can not be safely withdrawn from antihypertensive therapy).

- Clinically significant changes in health status or concomitant prescription
medications within 2 weeks prior to dosing (V3 Day 0) that could place the subject at
risk for dosing with study drug or confound the primary or secondary outcome measures
as assessed by the Investigator.

- Unstable/underlying cardiovascular disease defined as: a. Congestive heart failure
(NYHA class III-IV), stroke, transient ischemic attack, unstable angina pectoris, or
myocardial infarction within the 6 months prior to screening (V1) b. Mean triplicate
12-lead ECG demonstrating a QT interval (corrected using Fridericia's formula (QTcF))
>450 msec in males and >470 msec in females at Screening, (V1) or a history or
evidence of long QT syndrome. c. Sustained heart rate >100 beats per minute (BPM) (at
rest) at screening (V1), prior to randomization (V3 Day -1), or prior to dosing (V3
Day 0). d. Any episode of atrial fibrillation, ventricular tachycardia (defined as
ten (10) or more beats with heart rate greater than 130 beats per minute),
ventricular fibrillation, firing of an implantable cardiac defibrillator (ICD) for
documented ventricular ectopy, or other clinically significant documented arrhythmias
within 3 months prior to administration of study drug (V3 Day 0).

- Uncontrolled diabetes defined as a Hemoglobin A1c > 10.0%. Note: only applicable for
subjects with a known or suspected history of diabetes.

- Clinically significant renal and/or hepatic dysfunction at Screening (V1) or at
baseline (V3 Day -1).

- Pregnant or lactating females.

- Known history of or active drug or alcohol abuse within the 12 months prior to
screening (V1) and/or positive drug screen (for illicit drugs) or detection of
alcohol at baseline.

- Positive for Human Immunodeficiency Virus (HIV) antibodies, hepatitis B surface
antigen (HBsAg) or hepatitis C virus (HCV) antibodies.

- Participation in any other study and have received any other investigational drug or
device within 30 days prior to the Screening visit or are taking part in a non-drug
study which in the opinion of the Investigator would interfere with the outcome of
the study.

- Major surgery, donated or lost > or = 1 unit of blood (approximately 500 mL) within
30 days prior to Screening (V1) or display evidence of volume depletion (i.e.,
postural hypotension) prior to randomization (V3 Day -1) or dosing (V3 Day 0).

- Other medical or psychiatric condition which in the opinion of the Investigator would
place the subject at increased risk, would preclude obtaining voluntary consent, or
would confound the results of the study.