FDA approves lumasiran as first drug for primary hyperoxaluria type 1

The FDA has approved lumasiran (Oxlumo) as the first drug for the treatment of patients with primary hyperoxaluria type 1 (PH1). The drug is approved for both adult and pediatric patients.¹

Patients with this rare metabolic disorder produce excess oxalate, which, when combined with calcium, can cause kidney stones and loss of kidney function. Lumasiran works by inhibiting the production of oxalate.

“The approval of Oxlumo represents a great triumph of community involvement to address a rare disease. It is a result of input from patients, treating physicians, experts and sponsors at a patient-focused drug development meeting and through other collaborative efforts,” Norman Stockbridge, MD, PhD, director of the Division of Cardiology and Nephrology in the FDA’s Center for Drug Evaluation and Research, stated in a press release.

The approval of lumasiran was supported by data from the phase 3 ILLUMINATE-A and ILLUMINATE-B studies.

The phase 3 open-label ILLUMINATE-A trial (NCT03681184) included 39 patients aged ≥6 years with PH1. Overall, 26 patients were randomized to lumasiran and 13 were randomized to placebo.

In the treatment arm, patients received subcutaneous lumasiran monthly for 3 months followed by quarterly maintenance doses at 3 mg/kg. The primary outcome measure was percent change in 24-hour urinary oxalate excretion from baseline tomonth 6.

Among patients in the lumasiran arm, there was a 65% average reduction of oxalate in the urine compared with an average reduction of 12% in the placebo arm. Over half (52%) of patients receiving lumasiran achieved a normal 24-hour urinary oxalate level at 6 months, compared with no patients in the placebo group.

Regarding safety, investigators determined the drug to be safe and tolerable. No severe or serious adverse events (AEs) were reported and there were no patient deaths.² All AEs were mild to moderate. The most common AE was injection site reactions, which occurred in 35% of patients.

The open-label, single-arm phase 3 ILLUMINATE-B trial (NCT03905694) evaluated lumasiran in patients aged under 6 years with PH1. Among 16 evaluable pediatric patients, lumasiran treatment led to an average decrease of 71% in urinary oxalate at the 6-month point of the study.

The investigators reported that lumasiran had an acceptable safety profile in the pediatric population.³ No patients discontinued treatment or withdrew from the study, and no severe AEs or patient deaths occurred. The most common AE was mild injection-site reactions, which occurred in 3 patients. Also, there were no clinically relevant changes in laboratory measures, vital signs, or electrocardiograms.

According to the FDA, approximately 80% of all PH cases are PH1, and the rare disease affects an estimated 1 to 3 people per million in North America and Europe.

Lumasiran was also recently approved in the European Union for the treatment of PH1 in both pediatric and adult patients.

References

1. FDA Approves First Drug to Treat Rare Metabolic Disorder. Published online November 23, 2020. https://www.fda.gov/news-events/press-announcements/fda-approves-first-drug-treat-rare-metabolic-disorder. Accessed November 23, 2020.

2. ILLUMINATE-A Phase 3 Results for Lumasiran Presented at ERA-EDTA. Published online June 7, 2020. https://www.alnylam.com/2020/06/07/era-edta-2020. Accessed November 23, 2020.

3. ILLUMINATE-B Phase 3 Results for Lumasiran Presented at ASN. Published online October 22, 2020. https://www.alnylam.com/2020/10/22/asn-2020. Accessed November 23, 2020.