Patients with primary hyperoxaluria type 1 have high levels of glyoxylate which is converted into oxalate. High levels of oxalate can cause stones in the kidney as well as injury to certain organs.

The active substance in Oxlumo, lumasiran, blocks the production of an enzyme called hydroxyacid oxidase (also known as glycolate oxidase), which is involved in the production of glyoxylate. Oxlumo is a ‘small interfering RNA’ (siRNA), a very short piece of synthetic genetic material, which has been designed to attach and block the genetic material in the cell that is responsible for the production of the enzyme. This blocks the production of the enzyme, thereby reducing the amount of glyoxylate and oxalate, helping to relieve the symptoms of the disease.