FDA APPROVES EXTENDED INDICATION FOR ASTELLAS' VAPRISOL

Astellas announced that the FDA has approved Vaprisol, an arginine vasopressin receptor antagonist, for the intravenous treatment of hypervolemic hyponatremia in hospitalized patients.

Vaprisol (conivaptan hydrochloride), discovered and developed by Astellas, is the first drug specifically indicated for the treatment of both euvolemic and hypervolemic hyponatremia, potentially life-threatening conditions that occur when the body's blood sodium level falls significantly below normal. Vaprisol was approved by the FDA as a treatment for euvolemic hyponatremia in 2005.

In the treatment of hyponatremia associated with congestive heart failure, Vaprisol is indicated only for those patients for whom the expected benefit of raising serum sodium outweighs the increased risk of adverse events, according to the company.

In a randomized, double-blind, placebo-controlled study, intravenous administration of Vaprisol 40 mg/day for four days achieved a clinically meaningful aquaresis, which resulted in increased serum sodium levels in hospitalized patients with hypervolemic hyponatremia. Aquaresis is defined as the excretion of electrolyte-free water. Significant increases in serum sodium levels were observed within the first day of treatment with Vaprisol and continued throughout the remainder of the treatment period.