A double blind, placebo-controlled, dose ranging study in males over the age of 65, who have a history of nocturia. The study will investigate pharmacodynamic outcomes (urine volumes and osmolality, circulating coagulation factors and haemodynamics) and pharmacokinetics, of both single and multiple oral doses of VA106483 at three dose levels, under conditions of controlled hydration.

VA106483 is a selective vasopressin V2 receptor agonist which is currently under development for the treatment of nocturia in males. This study examines the pharmacological action of VA106483 on markers of clinical efficacy (urine volumes and osmolality) and safety markers (coagulation factors and haemodynamics). The study will also assess the pharmacokinetics in the study population. The study design includes both cross-over and parallel phases so that pharmacodynamic and pharmacokinetic parameters can be assessed following both single and repeat dosing. Three dose levels will be given.

Inclusion Criteria:

• Males 65 years and above with history of nocturia

Exclusion Criteria:

• Any clinically significant concomitant medical disease, condition or abnormal laboratory test result
• Participation in any other clinical study within 30 days
• Intake of non-prescription medication within 14 days