MMF, a metabolite of an MS drug (DMF) has the ability to counteract two of the primary causes of progression in Parkinson's, inflammation and oxidative stress. It has already shown success in controlling these factors in mice with chemically-induced Parkinsonism. The researchers are moving toward a clinical trial. MMF, or a related drug, should be helpful for those in the earlier stages of the disease, who still have a reasonable number of functioning dopaminergic neurons:
"If we can catch them early enough, maybe we can slow the disease," Morgan said."If it can help give five to eight more years of improved quality of life that would be great for our patients."
[Paula, My post was directed at people in the Parkinson's (Disease) Movement. You seem to be in the AFA (Atrial Fibrillation Association.) So I am puzzled why you even read my post. We should be invisible to each other, like ghost ships passing in the night. But, in any case, my answer follows.]
What makes you think there is any relation? Exenatide is a diabetes drug that has nothing at all to do with controlling inflammation or oxidative stress, the two biggies of MMF. Here is what Wikipedia has to say about Exenatide:
'Indications
Exenatide is approved "as adjunctive therapy to improve glycemic control in patients with type 2 diabetes mellitus who are taking metformin, a biguanide, or a combination of metformin and a sulfonylurea, but have not achieved adequate glycemic control." '
Whilst a I am an AFer, my wife has PD and has just completed the clinical trial of Exenatide. We should know in a few weeks if she was on the drug or the placebo and then we will be given the full trial results by Septmber/October. I believe that Exenatide does have an effect on inflammation, butI am not a doctor, so I recommend you search the Parkinson's UK Facebook site and look for the "Can old drugs perform new tricks". In this video, the doctor, Dilan Athauda, who is running this trial under consultant Dr Tom Foltynie, explains in detail about this drug and its potential effects for PD patients. I am sorry not to give you a link to click on, but it does not look possible to do this from Facebook using my iPad and this is all I have with me at the moment.
From dumplekin reply they are very different meds. The exenatide trials are still ongoing I believe. 2014 report
The conclusion from the trial was that while these data must still not be interpreted as evidence of neuroprotection, they nevertheless provide strong encouragement for the further study of this drug as a potential disease modifying agent in Parkinson’s disease.
The links you included with your comments are associated with the Phase 1 trial of Exenatide. The Phase 2 trial is completing now and results should be published in the autum. If you can find the presentation video I refer to in my earlier post, responding to the first post by Dumpelkin in this stream, you will hear the detailed biochemical arguments and evidence for Exenstide.
The anecdotal evidence of this Phase 2 trial is encouraging, but until the full results are published this does not mean a great deal.
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Sickening... we are paying for medication... to keep us paying for more medicatio. 
