I will begin answering, and my colleague may have something to add.
For Alzheimer's disease, symptomatic treatments in use currently are administered for six months to two years on the average, and clinical trials to demonstrate their effectiveness last six months. In that case the approval and trial period under the current Patent Act is appropriate.
To prevent Alzheimer's disease among certain high-risk populations, we may have to use new molecules that modify amyloid or other protein deposits in the brain. The trial period will then be from five to seven years for the crucial phase III studies. For preventive treatment of younger patients where we would like to see very early intervention, trial periods could last for 10 years. So in those cases, we see that the trial period would be much longer than usual with regard to the current patent protection.