 The study period will consist of a 28-week trial period. The participants who fulfill the inclusion criteria and not meeting any of the exclusion criteria will be enrolled, and randomized in a 1:1 ratio to either the 1 mg of TVP-1012 or the placebo group. In each treatment group, participants will receive either 1 mg of TVP-1012 or placebo once daily in a double-blinded manner. 