Alnylam gets CHMP backing for second gene-silencing drug Givlaari

Alnylam could be weeks away from getting its second RNA interference drug approved in Europe, after a CHMP green light for its rare disease drug Givlaari.

EMA’s human medicines committee the CHMP gave Givlaari (givosiran) a positive opinion for the treatment of acute hepatic porphyria (AHP) in adults and adolescents aged 12 years and older, a couple of months after the drug was approved by the US FDA.

The positive opinion is another step forward for Alnylam in what is shaping up to be a pivotal year for the gene-silencing specialist as it tries to grow Givlaari and first approved product Onpattro (patisiran) for hATTR amyloidosis, and gears up for a possible approval of a third product – lumasiran – for primary hyperoxaluria.

In a statement, the CHMP said that Givlaari is the first treatment in Europe for AHP, a rare life-threatening genetic condition that causes attacks of severe abdominal pain, vomiting and nervous system disorders, such as seizures, depression and anxiety.

It’s caused by a lack of certain enzymes needed to produce haem, part of the oxygen-carrying haemoglobin molecule, which results in the accumulation of compounds called porphyrins in the body.

Givlaari has been reviewed under the EMA’s PRIME scheme, which allows more rapid approval for drugs that represent a significant advance over current therapies or are the first for a disease. A final verdict typically comes from the EU regulator within a couple of months.

At the moment, intravenous hemin – a human blood-derived haem formulation – can be used to treat acute AHP attacks, but isn’t approved to prevent attacks.

In the US, Givlaari has been launched with a hefty price tag – around $575,000 per patient per year – although Alnylam has tried to soften the blow with a money back guarantee if it isn’t effective and rebates for payer formularies who have more AHP than expected in their health plans.

Alnylam’s chief executive John Maraganore has said he thinks the company can build the drug to $500 million annual sales at peak.

Alnylam updated on the initial roll-out of its two commercial products at the JP Morgan healthcare conference last month, saying it expects Onpattro to achieve slightly better-than-expected sales of $56 million in the fourth quarter – taking the 2019 total to around $166 million – while Givlaari brought in around $200,000 in “initial channel stocking”.

The company has been working in the US to improve access to third-party genetic testing for the mutation associated with AHP. It has also forged an alliance with gastrointestinal disease specialist Ironwood Pharma to raise awareness of the drug and testing among gastroenterologists, who are often involved in the care of AHP patients.

The estimated global prevalence of AHP is in the range of two to five per 100,000 for people with systemic or systematic disease, and there are thought to be roughly 1,000 diagnosed patients in US and Europe who are severely affected and experience recurrent attacks. Many patients with active disease remain undiagnosed.