Kobo's tech specs do not include DRM ePUBS as supported file formats for Kobo on the VOX. I know a lot of people use magic to remove the DRM and read the books using the Vox Kobo app. IMO, this is one of the differentiators between the Vox and the Touch. If the Touch couldn't make use of Adobe DRM books, it would be a much bigger deal.
The Kobo Vox App is an early version. Things change fairly dramatically over time. This could change in the future.
http://www.kobobooks.com/kobovox_tech