Alnylam Pharmaceuticals has scored an approval from the European Commission for its RNAi therapeutic Oxlumo, for the treatment of primary hyperoxaluria type 1 (PH1) in all age groups.

Oxlumo (lumasiran), an RNAi therapeutic, is designed to target the hydroxyacid oxidase 1 (HAO1) mRNA that encodes glycolate oxidase (GO) – an enzyme upstream of the disease-causing defect in PH1.

The degradation of the HAO1 mRNA and reduction in the synthesis of GO helps to stop the production of oxalate, the toxic metabolite that ‘directly contributes’ to causing PH1.

The EU approval is based on results from the phase III ILLUMINATE-A and ILLUMINATE-B of Oxlumo.

In the ILLUMINATE-A study, conducted in adults and children six years or older, Oxlumo treatment lead to a 53% reduction in urinary oxalate compared to placebo and a 65% mean reduction in urinary oxalate relative to baseline.

The ILLUMINATE-B, which evaluated Oxlumo in infants and children under the age of six years, scored similar efficacy and safety results to ILLUMINATE-A.

“Prior to now there have been no approved treatment options for PH1 in Europe, so this is a potentially life-changing milestone for people diagnosed with this ultra-rare, debilitating disease - many of whom are infants and children - and their families,” said John Maraganore, chief executive officer, Alnylam Pharmaceuticals.

“Oxlumo will address the urgent unmet need that exists for patients with PH1 and its approval today marks our continued commitment to rare disease communities,” he added.

PH1 is an ultra-rare disease characterised by excessive oxalate production, which can cause life threatening end-stage renal disease as well as other systemic complications.

If PH1 goes untreated, it can lead to progressive kidney damage – patients with advanced kidney disease  require intensive dialysis to help filter waste products, including oxalate, from the blood.