Shire plc shocked the rare disease community on March 14 when it announced it had withdrawn its BLA for Replagal agalsidase alfa to treat Fabry's disease less than two weeks before a scheduled FDA advisory committee meeting - and that it had no intention to resubmit a marketing application in the U.S.

This week, Shire is set to close down its treatment IND for Replagal, which has been providing U.S. Fabry's patients with access to the drug since October 2009. The move will culminate a cascade of events set in motion by a regulatory crisis that began with the now infamous manufacturing debacle at Genzyme Corp., which led to urgent efforts by FDA to find a substitute to compensate for the shortage of Genzyme's Fabrazyme agalsidase beta, the only drug approved in the U.S. for Fabry's.