An article of GACKT being the lead runner could be found in the following.

An article of GACKT being the lead runner of the 2015 Super Star Festa (SG 30th Super Star Championship )could be found in the following.
(random order)

Nikkan sports
http://www.nikkansports.com/public_race/news/1582126.html

Daily sports
http://www.daily.co.jp/newsflash/horse/2015/12/21/0008664868.shtml

Source: GACKT.com