UPDATE 1-Shire seeks Gaucher approval earlier than expected

* Submits new application for drug earlier than expected

* Follows successful Phase III trials

* Speed critical as supplies of rival Gaucher drug run out

* Has been given ‘fast track’ designation by FDA

(Adds details, background)

LONDON, Sept 1 (Reuters) - Britain's Shire SHP.L has submitted an approval application for its new Gaucher disease drug to U.S. authorities earlier than expected, it said on Tuesday, providing hope to sufferers of the disease as supplies of a rival drug start to run out.

The approval process became a race against time after Genzyme GENZ.O was forced to cease production of the main drug for the disease, Cerezyme, when its manufacturing site became infected with a virus. [ID:nN16267721]

Shire said that it has completed two remaining Phase III trials, clearing the way for the drug approval application.

It plans to provide its Gaucher drug, velaglucerase alfa, initially free of charge in order to provide access to patients as quickly as possible.

However the problems at Genzyme will help Shire’s long-term plans for the drug as under normal circumstances Gaucher patients rarely change the drug they use, analysts say.

Patients with Gaucher are deficient in an enzyme that breaks down a certain type of fat molecule. Fatty cells accumulate in different parts of the body, including the spleen, liver and bone marrow.

Shire and Israel-based Protalix BioTherapeutics PLX.A have both received so-called "fast track" designation from the U.S. Food and Drug Administration for their Gaucher drugs, meaning that the approval process has been accelerated to get the drugs onto the market faster.