Alnylam has claimed European Commission approval for its second RNA interface (RNAi) drug Givlaari for acute hepatic porphyria.
The EU approval of Givlaari (givorsiran) comes a few months after the drug scored approval in the US for the rare condition.
Porphyrias are genetic metabolic disorders caused by an enzyme deficiency in the haem pathway, that leads to a build-up of toxic porphyrin molecules in the body. This causes attacks that lead to both tissue and organ damage.
Hepatic porphyrias occur due to a deficiency in the liver and are associated with painful attacks that often require hospitalisation and treatment with intravenous hemin therapy. Sometimes, the disease can lead to patients requiring a liver transplant.
The EU approval, like the FDA green light, was based on data from the phase 3 ENVISION trial, that involved 94 patients with acute hepatic porphyria who received the drug as a once-monthly subcutaneous injection or placebo.
The results from this trial were positive, showing that treatment with Alnylam’s drug reduced the annualised attack rate by 74% compared to control.
RNAi drugs work by switching off genes that don’t function properly – Givlaari targets the aminolevulinic acid synthase 1 (ALAS1) gene, which leads to a reduction in the number of toxins associated with the attacks that those with acute hepatic porphyria face.
“We are committed to bringing Givlaari to patients in Europe as rapidly as possible, and plan to build on our experience in the US by proactively engaging with national authorities in Europe around a value-based agreement framework which we hope will accelerate patient and provider access to Givlaari,” said Barry Greene, president of Alnylam.
The value-based agreements would work by determining the price of Givlaari based on how well patients respond to the drug.
Alnylam’s first RNAi drug – Onpattro (patisiran) for rare disease hereditary ATTR amyloidosis – has a similar pricing strategy.
Givlaari has a list price of $575,000 but Alnylam says that it will reduce the cost, after discounts, to around $442,000. Onpattro, on the other hand, launched with a $450,000 per year price tag, and subsequently dropped to $345,000 after discounts to the initial price.
In a Reuters report, analyst Leland Gershell at Oppenheimer predicted that sales of Givlaari could reach $560m at peak, with the approval in the EU likely to help it make this target.