US regulators have green-lighted Xuriden, the first therapy for patients with the ultra rare metabolic disorder hereditary orotic aciduria.

The disease, reported in just 20 children around the world, occurs because of a defective or deficient enzyme which results in the body being unable to normally synthesise uridine, a necessary component of ribonucleic acid.

Signs and symptoms of the condition include blood abnormalities (anaemia, decreased white blood cell and neutrophil counts), urinary tract obstruction, failure to thrive, and developmental delays.

Wellstat’s Xuriden (uridine triacetate) is an orally administered product intended to replace uridine, which, in clinical trials, was shown to stabilise blood-based markers in all four clinical trial participants, and caused no side-effects.