The are at least two bands named Nephthys:
1) Nephthys is a dutch doom/death metal band who only released a promo recently.
2) Nephthys is also band from Slovenia formed in 2008 by Dorian Žulič (vocals, guitars, keyboards) and Matej Kržišnik (drums). They released their first album Ghost Asylum in June 2011.

Nephthys on Last.fm.