The Food and Drug Administration approved the intravenous drug, known chemically as taliglucerase alfa, after rejecting it last year and asking the companies for more data.

Shares of tiny Israeli biopharmaceutical company Protalix jumped nearly 23 percent to $7.60 in after-market trading following the approval of its leading product, which the companies plan to sell under the name Elelyso.

A new drug could ease shortage worries in the $2 billion Gaucher market, which has been dogged by supply issues surrounding the leading therapy Cerezyme, made by Sanofi SA unit Genzyme.

Gaucher disease stems from an enzyme deficiency that prevents the breakdown of certain fats in the body. It can cause organ damage or death and affects about one in 50,000 to 100,000 people. It is particularly prevalent among Ashkenazi Jews, according to the National Institutes of Health.

Unlike most biotech drugs, which use cells from mammals, taliglucerase is the first to be made from plant cells, using genetically modified carrot cells.

The FDA said Elelyso had been granted orphan status, meaning it treats a condition or disease that affects fewer than 200,000 people in the United States. Now that the drug is approved, the companies get seven years of marketing exclusivity.

The drug specifically treats Type 1 Gaucher disease, which affects about 6,000 people in the United States, the FDA said.

Analysts have said a lower price for Pfizer and Protalix's new drug, as well as Pfizer's marketing prowess, should help the treatment win a significant share of the Gaucher market, which is expected to reach $4.5 billion by 2016.

Pfizer said it would price the drug 25 percent below Genzyme's Cerezyme, which sells for about $200,000 a year, according to Genzyme's website.

Genzyme earlier this year said new U.S.-based manufacturing plants should ease supply constraints over its Gaucher treatment.

But Shire Plc, which makes a rival Gaucher drug called Vpriv, last week said it had failed to win FDA approval to manufacture its drug at a new facility in Lexington, Massachusetts.

Pfizer will try to minimize supply disruptions for patients by keeping 24 months of inventory on hand to serve all the 1,500 to 2,000 patients currently treated for Gaucher in the United States, the company told a briefing before the FDA's approval.

Shares of Pfizer, which also reported earnings on Tuesday, closed down 0.7 percent at $22.78.

(Reporting by Anna Yukhananov; Editing by Tim Dobbyn and Dale Hudson)

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