I am very sceptical about these trials with neurotrophic factors. I read years ago that they don't work because the clumped alpha-synuclein interfere in the regeneration process of neurons. I have the same scepticism when it comes to beta amyloid removal being the cure for Alzheimer. I have read decades of research proving that beta amyloid removal is not the way to go but for some weird reason the scientific community keeps focusing on beta amyloid removal. In the meanwhile, tau removal seems to look more promising but it almost doesn't get any attention.