My brother was quite bad, I remember the alarm being on his bed. I don't think much worked, but he did grow out of it, it stopped when he was 9 or 10. I think my parents would take turns to get up a couple times a night to wake up to go to the loo and he eventually clicked.

Poor thing, its probably so embarrassing. Hope its resolved soon.
My son was the same, we tried everything but eventually we just had to wait till he grew out of it