Keith Arem was a Nexus-6 replicant who was used as a test subject for Night Owl. He died six minutes after exposure.[1]
Behind the scenes[]
The character is presumably named after the game's voice recordist, Keith Arem.
In the original film, there is a scene where Roy Batty asks Tyrell about EMS Recombination with regards to extending the Nexus-6 lifespan. Tyrell then recounts how tests on a subject created a virus so deadly that it killed the subject very quickly. The circumstances surrounding Keith Arem's death and the effects of Night Owl would seem to vaguely match Tyrell's description.