Enzyme replacement therapy (ERT) is a therapeutic approach in which the specific enzyme that is inactive or absent in affected individuals is replaced with functional enzyme molecule isolated or produced in the lab. ERT has been successful for the treatment of Gaucher Type 1, Fabry, MPS I, and Pompe disease. A phase I clinical trial for Niemann-Pick Type B has been completed, and Phase II is set to start in early 2011. ERT is effective in the non-neurological symptoms of lysosomal storage diseases, but has not yet proven to be beneficial in the diseases that primarily affect the central nervous system such as NPA since the replacement enzymes do not efficiently cross the blood-brain barrier.
To learn more on how enzyme replacement therapy works in Gaucher disease visit http://www.cerezyme.com/patient/treatment/cz_pt_treatment.asp