FDA approves Alnylam's second RNAi drug - with $442K annual price tag

Alnylam has had a second RNA interference (RNAi) drug approved by the FDA, to treat the ultra-rare disease acute hepatic porphyria, with an ultra-high price tag to match.

Givlaari will have an annual wholesale price tag of $575,000 based on a list price of $39,000 per vial although after discounts the figure will be around $442,000.

Alnylam said the FDA has approved the subcutaneous injection for the ultra-rare, genetic diseases that cause life-threatening attacks and symptoms that can negatively impact daily functioning and quality of life.

The FDA approved on the basis of clinical evidence showing Givlaari significantly reduced the rate of porphyria attacks that required hospitalisations, urgent healthcare visits, or intravenous hemin administration at home.

Approval by the FDA came earlier than expected: the regulator had granted a faster six-month review period but decided to grant a licence less than four months after accepting Alnylam’s filing.

The company said it expects the drug to be ready for shipment to US healthcare providers by the end of the year.

The FDA also approved it despite serious side effects occurring at a much higher rate than in the placebo group, around 21% versus 9%, although adverse events occurred at around the same rate in both groups, in 90% of Givlaari patients and 80% on placebo.

It’s worth noting that the patient group involved is already extremely sick, making it harder to distinguish drug-related events from the background noise caused by the disease.

Regulators from the European Medicines Agency are reviewing Givlaari under an accelerated assessment in AHP, after it was designated as a Priority Medicine.

This is the second RNAi drug approved from Alnylam, after Onpattro for hereditary transthyretin-mediated amyloidosis.

Alnylam also has competitors – Pfizer’s Vyndaqel treats the cardiac symptoms of amyloidosis, by binding to the transthyretin protein and slowing the formation of amyloid that causes damage to the heart.