Last week the band's lead singer Dan Nelson suddenly left the band due to health reasons. According to the band's website, "Dan Nelson unexpectedly informed the band that he was seriously ill and unable to travel or perform at this time."
Taking Anthrax's place on stage will be metal band Turisas, a Finnish metal band from Hämeenlinna with a self-styled Viking warrior theme.
Sonisphere is a massive metal music festival that tours Europe. This year it will hit Britain, the Netherlands, Germany, and Sweden in addition to Finland.
"Anthrax is already actively considering lead singer candidates, and look forward to hitting the road before the end of the year," says the band's website.