Pfizer enters US Gaucher disease market at a discount

Pfizer has been granted US approval for its type 1 Gaucher disease drug Elelyso at its second attempt, and will launch the drug at a 25 per cent discount to the current market leader.

Elelyso (taliglucerase alfa) was originally developed by Israeli biotechnology company Protalix and will enter a market currently served by Sanofi subsidiary Genzyme's Cerezyme (imiglucerase) and Shire's Vpriv (velaglucerase alfa), both of which have been affected by supply issues in recent months.

Type 1 Gaucher disease affects around 6,000 patients in the US, and because the disease is so rare Pfizer was able to secure approval on the strength of a phase III trial involving just 56 patients.

An earlier attempt to win approval was turned down in 2011 by the US FDA, which asked for more clinical and quality data.

"Today's approval provides for a new enzyme replacement therapy for the select number of patients with type 1 Gaucher disease," said Julie Beitz of the FDA's Center for Drug Evaluation and Research (CDER).

Around 2,000 US patients with the disease are on enzyme replacement therapy, and Pfizer is banking on discounted pricing to take market share from the established drugs.

Market leader Cerezyme costs $200,000-$300,000 per patient per year and is in the top 10 list of most expensive drugs worldwide, helping to drive a global market estimated to be worth around $2bn.

One reason for the discounted price stems from the manufacturing process for Elelyso, which is made in genetically-modified plant cells, rather than via mammalian cell culture.

Protalix' proprietary production platform uses carrot cells grown in bioreactors with lower capital and production costs and no risk of mammalian viral transmission. The company is also working on a new treatment for Fabry disease using the same production system.

Genzyme has only recently restored supplies of Cerezyme to near-normal levels after a viral contamination incident at its main facility for the drug in 2009 led to severe production disruptions.

Meanwhile, Shire has also seen its ability to supply the market pegged back after the FDA decided not to approve a US manufacturing facility for Vpriv in Lexington earlier this month.

Pfizer has said it intends to keep two years' inventory of Elelyso on hand at all times to avoid any supply disruptions.

Pfizer gained worldwide licensing rights to commercialise Elelyso, excluding Israel, in a 2009 deal that called for an upfront payment to Protalix of $60m as well as potential milestone payments of up to $55m. The Israeli firm has received $25m on the US approval.

Pfizer and Protalix agreed to split future revenues and costs relating to taliglucerase alfa on a 60-40 basis, respectively.