Sorry it took us a bit to get back to you on this. We won't always be able to answer individual research questions on the forum but to get a quick response, you can always write to us at firstname.lastname@example.org
We had a look into it but couldn't find any further information on GM1 ganglioside or new trials. The sort answer to your question is: research like this can take time. This was a relatively small, 'open label' (ie no placebo/control group) study.
So, while the results were promising, much larger and more comprehensive studies are required to follow this up. And setting up these kind of studies requires lots of money (many millions) - and this money can take a while to raise. The study was only published last year so it may take some time for further studies to be set up.
We'll update the website when there is more news.
In the meantime,take a look at the lead research news story on the website today. There's some exciting news.
For the first time, researchers in the US have successfully used nerve cells grown from human embryonic stem cells to repair the brain in animal models of Parkinson's: http://www.parkinsons.org.uk/about_us/news/news_items/all_news/stem_cells_into_brain_cells.aspx