A Clinical Study of Patients With Symptomatic NOH to Assess Sustained Effects of Droxidopa Therapy

This is a multi-center, multi-national, randomized, parallel-group, placebo-controlled,
double-blind study with a 17 week (maximum) treatment period consisting of an initial,
open-label dose titration (up to 2 weeks), followed by a washout period (up to 3 weeks),
followed by a 12 week treatment period on a stable dose.

Inclusion Criteria:

- 1. 18 years and older and ambulatory (defined as able to walk at least 10 meters);

2. Clinical diagnosis of symptomatic orthostatic hypotension associated with Primary
Autonomic Failure (PD, MSA and PAF), Dopamine Beta Hydroxylase Deficiency;

3. At the Baseline visit (Visit 2), patients must demonstrate:

1. a score of at least 4 or greater on the Orthostatic Hypotension Symptom
Assessment (OHSA) Item #1;

2. a fall of at least 20 mmHg in their systolic blood pressure, within 3 minutes of
standing;

4. Provide written informed consent to participate in the study and understand
that they may withdraw their consent at any time without prejudice to their
future medical care;

Exclusion Criteria:

- 1. Score of 23 or lower on the mini-mental state examination (MMSE);

2. Concomitant use of vasoconstricting agents for the purpose of increasing blood
pressure;

1. Patients taking vasoconstricting agents such as ephedrine, dihydroergotamine, or
midodrine must stop taking these drugs at least 2 days or 5 half-lives
(whichever is longer) prior to their baseline visit (Visit 2) and throughout the
duration of the study;

3. Known or suspected alcohol or substance abuse within the past 12 months
(DSM-IV definition of alcohol or substance abuse);

4. Women who are pregnant or breastfeeding;

5. Women of child bearing potential (WOCP) who are not using at least one method
of contraception with their partner;

6. Male patients who are sexually active with a woman of child bearing potential
(WOCP) and not using at least one method of contraception;

7. Untreated closed angle glaucoma;

8. Diagnosis of hypertension that requires treatment with antihypertensive
medications (short-acting antihypertensives to treat nocturnal supine HTN are
allowed in this study) Any significant uncontrolled cardiac arrhythmia;

9. History of myocardial infarction, within the past 2 years;

10. Current unstable angina;

11. Congestive heart failure (NYHA Class 3 or 4);

12. History of cancer within the past 2 years other than a successfully treated,
non-metastatic cutaneous squamous cell or basal cell carcinoma or cervical
cancer in situ;

13. Gastrointestinal condition that may affect the absorption of study drug
(e.g. ulcerative colitis, gastric bypass);

14. Any major surgical procedure within 30 days prior to the Baseline visit
(Visit 2);

15. Previously treated with droxidopa within 30 days prior to the Baseline visit
(Visit 2);

16. Currently receiving any other investigational drug or have received an
investigational drug within 30 days prior to the Baseline visit (Visit 2);

17. Any condition or laboratory test result, which in the Investigator's
judgment, might result in an increased risk to the patient, or would affect
their participation in the study;

18. The Investigator has the ability to exclude a patient if for any reason they
feel the subject is not a good candidate for the study or will not be able to
follow study procedures.