I've been doing a little research:
It is a qualification (as suggested by the name!), and UCAS points can be awarded for it...
EPQ grade A* A B C D E
UCAS points 70 60 50 40 30 20
(source: AQA website - these scores are equivalent to 1/2 an Alevel)
However, you may well be better off doing another AS instead, although most Universities encourage students to do the EPQ, not all of them include it under "entry requirements" - I believe this means it isn't always counted as a formal qualification.