General Information

Xuriden (uridine triacetate) is a pyrimidine analog.

Xuriden is specificaly indicated for the treatment of hereditary orotic aciduria.

Xuriden is supplied as a granules for oral administration. Measure the dose using either a scale accurate to at least 0.1 gram, or a graduated teaspoon, accurate to the fraction of the dose to be administered. Administer the dose with food (applesauce, pudding or yogurt) or in milk or infant formula. See full prescribing information for preparation and administration instructions. The recommended starting dosage is 60 mg/kg once daily; the dose may be increased to120 mg/kg (not to exceed 8 grams) once daily for insufficient efficacy. Please see the full prescribing information for 60 mg/kg and 120 mg/kg weight-based dosing tables.

Clinical Results

FDA Approval

The FDA approval of Xuriden was based on an open-label study in 4 patients with hereditary orotic aciduria (3 male, 1 female; age range from 3 to 19 years). Three patients were previously treated with uridine and were switched at study entry to Xuriden. All patients were administered Xuriden orally at a daily dosage of 60 mg/kg once daily. The study duration was 6 weeks. The study assessed changes in the patients’ pre-specified hematologic parameters during the 6-week trial period. The pre-specified hematologic parameters were: neutrophil count and percent neutrophils (Patient 1), white blood cell count (Patient 2), and mean corpuscular volume (Patients 3 and 4). For patients switched from oral uridine to oral Xuriden (Patients 1, 2, and 3), the primary endpoint was stability of the hematologic parameter; for the treatment-naïve patient (Patient 4), the primary endpoint was improvement of the hematologic parameter. After six weeks of treatment, Patients 1 and 3 met the pre-specified criteria for stability of the hematologic parameter. When Patient 2 was switched from uridine to Xuriden treatment, the prespecified criteria for white blood cell count remained stable; however documentation of a low white blood cell count prior to uridine initiation was not available. Patient 4 did not meet the pre-specified endpoint of improvement of the hematologic parameter.

Mechanism of Action

Xuriden (uridine triacetate) is an acetylated form of uridine. Following oral administration, uridine triacetate is deacetylated by nonspecific esterases present throughout the body, yielding uridine in the circulation. Xuriden provides uridine in the systemic circulation of patients with hereditary orotic aciduria who cannot synthesize adequate quantities of uridine due to a genetic defect in uridine nucleotide synthesis.