Zavesca blev udpeget som lægemiddel til sjældne sygdomme den 18. oktober 2000 for Gauchers sygdom type 1 og den 16. februar 2006 for Niemann Picks sygdom type C.
Because the number of patients with these diseases is low, they are considered ‘ rare’, and Zavesca was designated an ‘ orphan medicine ’ (a medicine used in rare diseases) on 18 October 2000 for type 1 Gaucher disease and on 16 February 2006 for Niemann Pick type C disease.