It was originally thought that this was Kate Beckinsale's last movie playing the character Selene, but Len Wiseman has confirmed a sixth movie is in development with Beckinsale reprising her character.
This is the directorial debut for Anna Foerster who often worked with Roland Emmerich (starting as director of photography for the visual effects camera unit on Independence Day (1996)). Producer Len Wiseman also worked with Emmerich as a prop assistant on Independence Day as well as Stargate (1994) and Godzilla (1998).
The ending in Underworld: Blood Wars (2016) is open-ended which will lead to the beginning of the sixth film in the series says producer Len Wiseman. Which is also said to be starring Kate Beckinsale for the role of Selene one last time, for one final fight which starts in this film, the release date, director, plot and title have not yet been confirmed for the sixth film.
Tobias Menzies, James Faulkner, and Charles Dance have all been members of The Game of Thrones cast. Respectively as Edmure Tully Lord of Riverrun imprisoned by the Freys, Tywin Lannister killed on the toilet and Lord Randyll Tarly Samwells father owner of the Valyrian steel sword Heartsbane. Though the three share no screen times with one another.