Low Blood Sodium (Hyponatremia)

September 22, 2014

Ultragenyx Pharmaceutical issued results of a phase I/II extension study of KRN23 (UX023) in adult patients with X-linked hypophosphatemia (XLH). The extension study (INT-002) was designed to follow an initial four-month dose escalation study (INT-001) that was conducted in the U.S. and Canada. 22 adult patients with XLH were evaluated over an additional 12 months. Patients received monthly subcutaneous injections of KRN23 administered at a dose range of 0.1mg/kg to 1mg/kg. Data demonstrated the increases in serum phosphorus levels, urinary phosphorus reabsorption and 1,25 dihydroxy vitamin D levels observed in the initial INT-001 study were generally sustained during the 12-month extension. All patients continued to demonstrate increases in serum phosphorus levels. Approximately 52.6%-85.7% of subjects in the extension study had serum phosphorus levels that reached the normal range (2.5mg/dL to 4.5mg/dL) at peak time on day seven or day 14 after each dose over this 12-month period. The company plans to continue development in adult XLH patients and is enrolling pediatric XLH patients in an ongoing phase II study.

September 27, 2004

Yamanouchi Pharma America announced data from a clinical study of conivaptan, their vasopressin receptor antagonist for the treatment of dilutional hyponatremia, abnormally low concentrations of serum sodium due to increased body water. The results indicated that conivaptan was able to significantly increase serum sodium levels over the treatment course (the primary endpoint), reach these levels faster, and maintain these increases for a greater period of time (the secondary endpoints), versus placebo. This double-blind, multi-center study enrolled a total of 84 subjects suffering from symptomatic dilutional hyponatremia, including serum sodium levels of 115-130 mEq/L; subjects were treated with placebo or a regimen of 20 mg IV bolus of conivaptan followed by continuous infusion of one of two doses of the drug (40 mg/day or 80 mg/day) for 4 days. An NDA for conivaptan is currently being reviewed for approval by the FDA for the treatment of euvolemic and hypervolemic (dilutional) hyponatremia.