UK Radio 2 show on Monday 4th September (available for several days on iplayer radio) was about a diabetes drug called Exenatide thats looks to be able to slow PD progression? they are looking to do a second larger trial and will want volunteers. Already being used for diabetes so safety for human use already established.
Radio show here, relevant segment starts at 1:08 hrs in and goes on to 1:31
Pinches of salt at the ready I know but another step in the right direction?