Here is his statement from Slashfilm:
“There is a lot more there. There’s probably 45 minutes of scenes that never saw the light of day. Out of all of it, I’d say there could be 10-15 minutes, maybe more with a few additional visuals effects, that could go into that film. A lot of the stuff that got cut out of The Box was big, eccentric, head-trip stuff. Now, I think all these years later, audiences are a little more open to cerebral sci-fi material… I think it would be really exciting to expand upon the world we were exploring in that film. That could happen. I would love to revisit The Box at some point because I do think there is a lot more there, a lot more big science-fiction ideas. There were also a lot of big set-pieces that got cut. Expensive stuff. I was proud we pulled it off and shot it.”
Few deleted scenes that are available are Arthur (James Marsden) and Norma (Cameron Diaz) debating pressing the button, a chase scene with Arthur in the library, and an eight-minute-long action sequence near the film’s end.
Source material: Slashfilm