FDA Approves Alnylam's Oxlumo To Treat Rare Metabolic Disorder

(RTTNews) - The U.S. Food and Drug Administration approved the first drug to treat primary hyperoxaluria type 1 (PH1), an ultra-rare genetic disorder which causes recurrent kidney stones and loss of kidney function.

Alnylam Pharmaceuticals' Oxlumo (lumasiran) in the form of injection lowers urinary oxalate levels in pediatric and adult patients. It is also the only therapy proven to lower harmful oxalate levels that drive the progression of PH1 disease.

Oxlumo is expected to be available for shipment to healthcare providers in the U.S. by year-end. The company also announced value-based agreements (VBAs) for Oxlumo to accelerate access for patients and deliver ultra-rare orphan disease pricing solutions to U.S. payers. It has reached an agreement in principle with Express Scripts, Harvard Pilgrim, and Highmark to pursue VBAs.

PH1 is an ultra-rare orphan disease characterized by excessive oxalate production, which can lead to end-stage renal disease (ESRD) and other systemic complications due to the deposition of calcium oxalate crystals in the kidneys and urinary tract. PH1 affects approximately 3.5 to 4 individuals per million in Europe and the United States.

PH1 leads to progressive kidney damage, and patients with advanced kidney disease require intensive dialysis to help filter waste products from their blood until they are able and eligible to receive a dual or sequential liver/kidney transplant. As kidney function worsens, oxalate can build up and damage other organs, including the heart, bones and eyes.

Oxlumo is an RNAi therapeutic targeting hydroxyacid oxidase 1 (HAO1) for the treatment of primary hyperoxaluria type 1 (PH1) in all age groups. It works to decrease oxalate production. HAO1 encodes glycolate oxidase (GO), an enzyme upstream of the disease-causing defect in PH1.

The approval for Oxlumo was granted based on the results of both ILLUMINATE-A and ILLUMINATE-B Phase 3 Studies in patients with PH1, one a randomized, double-blind, placebo-controlled trial involving 39 patients six years and older, and another open-label trial involving 16 patients younger than six years.

Both the studies demonstrated clinically significant reductions in urinary oxalate and encouraging safety and tolerability across a broad spectrum of patient ages.

In the first study, the primary endpoint was the amount of oxalate measured in the urine over 24 hours, which was an average 65 percent oxalate reduction in the Oxlumo group, compared to an average 12 percent reduction in the placebo group. 52% of patients treated with Oxlumo also reached a normal 24-hour urinary oxalate level by the sixth month.

The second study showed an average 71 percent decrease in urinary oxalate by the sixth month while using another measure of oxalate in the urine. For the treatment of PH1, Oxlumo received orphan drug designation, which provides incentives to assist and encourage drug development for rare diseases. Additionally, the application was granted breakthrough therapy designation and priority review.

Last week, the European Commission (EC) had granted marketing authorization for Oxlumo for the treatment of primary PH1 in all age groups. The approval was based on efficacy and safety findings from both the Phase 3 studies of Oxlumo.