Shire’s stock was given a lift after US regulators approved a treatment protocol for its investigational Fabry disease agent Replagal, giving patients with the rare disorder early access to the drug to help fill the void left by shortages of Genzyme’s Fabrazyme.

In June, Genzyme was forced to temporarily shut down its manufacturing facility in Boston after a bioreactor was contaminated with a virus, leading to a severe shortage of Fabrazyme (agalsidase beta) - the only marketed Fabry disease drug in the US - as well as Cerezyme (imiglucerase) for Gaucher disease.

Shire was subsequently approached by the US Food and Drug administration to file treatment protocols for Replagal and its investigational Gaucher disease therapy velaglucerase alfa, so that patients could have access to these drugs before they become commercially available.

Gaucher disease patients in the US are already receiving velaglucerase alfa under an early access programme and now those with Fabry disease will also be given Replagal - initially free of charge to facilitate faster treatment - before it receives full regulatory clearance in the country.

Shire also announced that is plans to file a Biologics License Application with the FDA for Replagal by the end of the year, moving the agent a step closer to approval in the world’s biggest drug market.