Compared with placebo , mean daily off-time was significantly reduced in the combined tozadenant @ mg twice-daily and @ mg twice-daily group ( -@ h , @ % CI -@ to -@ ; p = @ ) , the tozadenant @ mg twice-daily group ( -@ h , -@ to -@ ; p = @ ) , and the tozadenant @ mg twice-daily group ( -@ h , -@ to -@ ; p = @ ) .