There is no cure, never has been; neither will there be. The best that can be done is to change the nerve's biology. Unless surgical procedures could perfect nerve transplants or deal with the nerve via some sort of nanotechnology that hasn't been discovered as yet, no cure will be available in the near or foreseeable future.
Not to pour cold water over this, but occasionally, after everything possible has been tried, sometimes the disease is pronounced intractable; that is, nothing can be done to alleviate the symptoms, but this is only in rarer instances.