On Nov. 23, 2020, the U.S. Food and Drug Administration (FDA) approved Alnylam Pharmaceuticals’s Oxlumo (lumasiran) as the first treatment for primary hyperoxaluria type 1 (PH1), a rare genetic disorder.

This approval is a cumulation of the work of experts and community members coordinated by the Oxalosis & Hyperoxaluria Foundation and the Kidney Health Initiative.

Primary hyperoxalurias (PHs) are caused by excess production of oxalate, a substance consumed in food and also produced by the body. PH1 is the most common and severe type. PH1 affects an estimated one to three individuals per million in North America and Europe and accounts for approximately 80% of PH cases.

Patients with PH1 produce far too much oxalate, which can combine with calcium to cause kidney stones and deposits in the kidneys. Patients can experience progressive kidney damage, which can lead to kidney failure and the need for dialysis (a treatment that purifies the blood). As kidney function worsens, oxalate can build up and damage other organs, including the heart, bones and eyes.