Assistant Managing Editor

As Shire plc gears up for an early 2010 PDUFA date for its enzyme replacement therapy velaglucerase alfa in Gaucher's disease, potential competitor Protalix BioTherapeutics Inc. reportedly is being eyed by pharma giant Pfizer Inc. for a possible collaboration or even outright acquisition.

Israeli newspaper TheMarker reported earlier this week that Pfizer execs had visited the Carmiel, Israel-based biotech, which previously has stated its intention to partner late-stage Gaucher ERT Uplyso (taliglucerase), a drug poised to hit the market next year and take on Genzyme Corp.'s market leader Cerezyme (imiglucerase).

But New York-based Pfizer, fresh off its $68 billion acquisition of Wyeth, also might be interested in the company's underlying plant cell-based manufacturing system aimed at producing markedly cheaper biologics.

Nor is Pfizer the only potential suitor. The rumor mill also has pointed to interest from Jerusalem-based Teva Pharmaceutical Industries Ltd., another company that's been making inroads in the biogeneric space.

Shares of Protalix (AMEX:PLX), which have continued to rise - leaping more than 415 percent just this year - dipped 2 cents Wednesday, to close at $10.70.

Most of the company's news to date has focused on its Gaucher drug - some of that at the expense of Genzyme's manufacturing troubles earlier this year, which prompted regulatory authorities to call on Protalix and Basingstoke, UK-based Shire to help fill any potential Gaucher drug shortfalls caused by the temporary shutdown of Genzyme's Allston Landing plant. (See BioWorld Today, June 17, 2009.)

And last month, Protalix's 31-patient Phase III study of Uplyso solidly met its primary endpoint, and importantly, showed little immunogenicity, putting to rest much of the skepticism that had kept investors cautious on the plant cell-based recombinant form of glucocerebrosidase.

The company anticipates filing for approval by the end of this year. Assuming priority review, Uplyso could hit the market by mid-2010.

Competition also could come from Shire's velaglucerase, which was granted priority review with a Feb. 28, 2010, review date, as well as from Genzyme's Cerezyme, which remains well entrenched in the market despite the earlier Allston debacle.

But pricing likely will be key, and that's where Protalix has the edge.

Cerezyme costs about $200,000 per year and is Cambridge, Mass.-based Genzyme's most expensive product, pulling in a total of $1.2 billion in 2008.

But Protalix's plant cell-based manufacturing is significantly cheaper than Cerezyme's mammalian process involving Chinese hamster ovary cells - not to mention that it can avoid the type of contamination that plagued the Allston facility - and Protalix CEO David Aviezer told BioWorld Today last month that the aim is to price the product low enough to prompt patients to switch from Cerezyme to Uplyso. (See BioWorld Today, Oct. 16, 2009.)

Shire's velaglucerase is produced in a human cell line.

Gaucher's disease, a lysosomal storage disorder believed to affect about one in 20,000 live births, is characterized by the accumulation of glucocerebrosidase in the liver and also can lead to skeletal abnormalities and deformities, as well as anemia and thrombocytopenia.

Beyond Uplyso, Protalix's manufacturing technology, ProCellEx, which produces proteins through the genetic engineering of carrot cells, also could lend itself to cheaper biogeneric versions of existing biologics. The company already has started work on a version of antitumor necrosis factor-alpha drug Enbrel (etanercept, Amgen Inc.), which it hopes to market at a sharply discounted price to the original.

The company had about $29 million in cash as of June 30. As of Wednesday, its market cap, based on 76.5 million shares outstanding, was about $830 million.

Published  November 5, 2009