Some brands go as wide as 46 cm.

But I'd be concerned about going too wide. The ergonomics are different when your palms face each other, than they are on a flattie. You don't want your wrists to break to the inside, and you don't want weird stresses on your elbows.

What does your bike have on it now? Try 42s maybe. By measurement I should be on 38s, but c-c 38 is definitely too narrow for me (my wrists break to the outside), I'm happy on 40s now and I've been comfy on 42s in the past.