Protalix, Pfizer face fight for share after finally winning Gaucher approval


On the second pass Protalix BioTherapeutics won US approval for its Gaucher’s disease drug taliglucerase alfa, now dubbed Elelyso. The Israeli company and its US partner, Pfizer, must now make the most of what is seen as a missed opportunity.

By pricing Elelyso at a 25% discount to the market leader, Sanofi’s Cerezyme, the collaborators acknowledge that taking market share will be tougher than it would have been a year ago, when the incumbent was still limited by manufacturing restrictions. A less-expensive enzyme replacement therapy may be attractive to specialists and patients; however, persuading them to switch from a treatment that is working will be a bigger challenge.

Supply issues

Protalix’s US-listed shares rose 14% to a 14-month high of $7.05 on news of the company’s first approval. In a call for Protalix investors today, Vera Wu, Pfizer’s global asset lead for Elelyso, said the product would be available in mid-May.

In the call, the partners held out hope that continuing supply issues for its competitors may bestow a little bit of a helping hand. Production of one competitor, Shire’s Vpriv, may be constrained for some time since it received a complete response letter for production at its Lexington, Massachusetts, plant.

Shire said the delay, which the UK company announced along with its first quarter earnings last week, will not interrupt its ability to meet demand from new and existing patients, but acknowledged that “US inventory levels will be below target levels” until the FDA’s questions can be resolved.

Whilst Cerezyme production has scaled up, meanwhile, Sanofi does not expect to be able to accommodate any new patients or those needing to switch therapies.

Like its competitors, Protalix also has had its cell-based production lines challenged by the regulator, with its novel plant-based production platform the subject of an initial regulatory delay in 2010 (Protalix's woes continue with Uplyso setback, February 2, 2010).

Some 10,000 patients worldwide have Gaucher’s, meaning that while they can attach orphan pricing to their products the three companies are fighting over a very limited market – any stumble by a competitor is a significant opportunity to take share.

With Sanofi unable to accommodate any patient switchers, Protalix and Pfizer will have patients that can no longer take Vpriv all to themselves. And as they are seeking to position Elelyso as the most reliable product on the market, with a plan to have 24 months’ supply available, it may help attract new patients.

Diminished opportunity

However, there can be no doubt that what once was a promising outlook for Elelyso has dimmed. Back in 2008 analysts estimated the drug could be making sales of $200m by 2014. The outlook now sits at $47m in 2018 (Opportunity slipping from Protalix's grasp, February 8, 2011).

The two partners are co-marketing the product outside Israel, sharing costs on a basis of 60% to Pfizer and 40% to Protalix, meaning it can still be a significant earner for the Israeli partner.

But there can be no doubt that a chance to carve out a larger niche in the US has been missed. Lingering supply issues for its two competitors will help it establish itself, but the opportunity for Elelyso to play David to Cerezyme has shrunk.

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