If you start conditioning him to come to you other times when called and then reward him by tons of praise, petting, etc., he will eventually become less 'treat fixated'.
Sometimes with pups you have to catch them doing something good when you are not training them. So any tiny little movement towards you when you've spoken his name, go crazy on the praise - and occasionally give a small bit of a treat. Just to mix it up a bit. It's best if they don't know WHEN they might get a treat but that if they do something well and make you happy, maybe - but always they will receive praise.
Hope that helps - I have a 15 month old malamute who is treat motivated to the max so have to be creative.