I wonder how much of the long approval time is due to just finding enough volunteers?
then you have just plain incompetence from companies like IMPAX labs who can't bring their new extended release C/L to market because of substandard mfg'ing practices.

can't forget that DBS still has a role in advanced PD and hopefully more improvements are in the pipeline.

and lets hope the gene therapy, stem cell, porcine implants and fetal transplant trials that are in process or about to start are successful.