Hi and welcome to Eye on Spain.
That's a tricky question and unless someone on here has also been involved with a clinical trial I'm not sure you're really going to find an answer to this.
Have you spoken to your doctor who is doing your trial to see if it could be transferred to a hospital in Spain? I assume they would have to check to see if a hospital in Spain is carrying out the same trial.
Also, how often do you have to visit your doctor? Could you move here and go back whenever you need to to either get the next dose of medicine or something like that?
Sorry not been much help.
Justin