There was a WAB supplement entitled, "Armies of Chivalry."
It covers the late medieval period but overlaps into the Italian Wars. The army lists include those that, I believe, fought in the Italian Wars: Holy Roman Empire to 1519, the Swiss to 1522, and French Ordonnance armies to 1503.
Borderline armies that, according to the lists, go until 1495 include: Italian Condotta, and the Low Countries. I believe these could be extrapolated into the early 1500s.
Of more significance are the additional rules to cover the capabilities of these armies to include artillery, handguns, heavier armor, formations, etc.
Although these aren't dedicated to the Italian Wars, it's a start.
Back in the day, when WAB was popular and still supported by Games Workshop, we played a few of these armies, although we didn't play the Italian Wars per se.