The purpose of this study is to determine whether Fipamezole is effective in the treatment of orthostatic hypotension and related symptoms in multiple system atrophy and Parkinson's disease.

This study will be an exploratory, proof of concept, randomised, placebo-controlled, double-blind, multiple crossover study, with an open-label active run-in phase, in patients with multiple system atrophy (MSA) or Parkinson's disease (PD) who can concomitantly be treated with fludrocortisone and antiparkinsonian medication. Three sites in France and one site in Portugal will participate in this study.

During the open-label active run-in phase, a tolerated dose-escalation regimen (either escalating from 30 to 90 or 60 mg tid, or no escalation but fixed dose of 30 mg tid) will be established for each patient. Once the tolerated treatment regimen has been established, patients will then be randomised to the double-blind crossover treatment. Fipamezole and matched placebo tablets are compared in 3 crossover blocks, each block consisting of a total of 28 days: 12 days fipamezole and 12 days placebo in random order, separated by two days of washout. The patients will be randomly assigned to one of the two possible treatment sequences (fipamezole first followed by placebo or placebo first followed by fipamezole).

For efficacy assessments, the patient blood pressure and heart rate is assessed repeatedly when laying still or standing. Impact of orthostatic hypotension on clinical symptoms is assessed with a subjective scale and questionnaire. To explore potential positive or negative impact of fipamezole on disease characteristics, the MSA and PD patients are assessed with UMSARS and UPDRS scales, respectively. Finally, the study includes investigator and patients assessments of CGI-I and PGI-I scales for clinical condition in general.

Fipamezole

Fipamezole is a new antagonist of the pre-synaptic adrenergic alpha-2 receptors and is being investigated for potential use as an adjunctive therapy for PD. Adrenergic alpha-2 receptors inhibit noradrenaline and some other neurotransmitter release from nerve terminals in a tonic manner, and therefore antagonism of this receptor leads in enhanced neurotransmitter release. Alpha-2 receptors are located widely in the body, both in the central nervous system (CNS) and periphery. Pharmacological studies have suggested that either central or peripheral autonomic nervous system is involved in autonomic failure and orthostatic hypotension in MSA and in PD. Neurogenic orthostatic hypotension in these diseases results from decreased delivery of the sympathetic neurotransmitter noradrenaline (or hormonal adrenaline) to vascular adrenergic receptors, either because of blunted CNS control or impaired function of postganglionic sympathetic neurons. Fipamezole is expected to increase noradrenergic (or adrenergic) turnover in specific areas of the brain or in the periphery in MSA and PD and alleviate symptoms related to fall in BP during orthostatism.

Inclusion Criteria:

• Male or female patients ≥ 30 and < 80 years of age with an intact oral mucosa at screening
• Diagnosis of MSA or diagnosis of idiopathic PD
• Hoehn and Yahr stages 1 to 4 during 'Off' period
• NOH: reproducible fall in SBP ≥20 mmHg and/or a fall in DBP ≥10 mmHg between 15 min of supine rest and 3 min of standing (or until symptomatic from hypotension after <3 min of standing)
• For patient taking antiparkinsonian medication: stable daily dosing for at least 1 month
• For patient taking fludrocortisone: stable dose for at least 2 months
• Demonstrated ability to comprehend, give informed consent and comply with study procedures (BP self-monitoring, completion of patient diary and self-assessment rating scales)

Exclusion Criteria:

• Other clinically significant conditions apart from those typically associated with MSA or PD
• SBP ≥200 mmHg or DBP ≥120 mmHg after 15 min supine rest in quiet environment
• Clinically significant abnormalities of ECG
• Mini-Mental State Examination (MMSE) score < 24
• Intake of prohibited concomitant medication such as midodrine, intake of medication associated with vasodilatation or induction of liver enzymes; neuroleptics; certain drugs known to be substantially metabolized through the following cytochrome P450 isoenzymes: 1A2, 2B6, 2C19, 2C9, 2D6 and 2E1; or any other drug for the treatment of orthostatic hypotension (including off-label use), such as non-steroidal anti-inflammatory drugs, beta blockers, somatostatin
• Use of St. John's Wort or Ginkgo Biloba within 48 h prior to inclusion and during the course of the study
• Intake of an investigational drug within 30 days prior to screening