There are multiple artists with this name:
1) Coma is a Polish alternative rock band, founded in 1998 in Łódź by Dominik Witczak (guitar) and Tomasz Stasiak (drums).
The first album "Pierwsze Wyjście z Mroku" was released in 2004. After winning the Rock Festival in Węgorzewo the band became very popular in Poland. The second album, "Zaprzepaszczone Siły Wielkiej Armii Świętych Znaków" was released in May 2006.
In 2008, after hiring a new drummer, Coma released the double concept album "Hipertrofia".