Grace Forrett's Mother writes a blog about Grace and Rett Syndrome. Here is a nice lay person's summary of some of the exciting research which is in progress and trialing of the drug NNz-2566. Her blog summarizes the research:

"NNZ-2566 is a medication being developed by the small pharma company Neuren. Neuren is a company in New Zealand which has offices in Australia and the United States. They have special interests in areas of neuroscience where there are gaps in development of treatments. Neuren currently has a growing portfolio on traumatic brain injury, neurodegenerative disorders and neurodevelopment disorders.
There are very few human clinical trials actually going on for Rett syndrome and NNZ-2566 is one of them. The trials are happening in America as we speak."