I did a tutorial on how to draft an underwire bra
Here are the files, if they will help you. I haven’t printed or tested the pattern in any way.
Basic Underwire Bra.val (31.2 KB)
Bra.vit (1.4 KB)
I used the instruction on this site: http://web.archive.org/web/20130115080343/http://www.patternschool.com/?page_id=230
I hope this helps