According to Rich Johnston there might be. (link)
"Okay, I'm not sure how much faith to put in this, the source isn't exactly the strongest one, but I've run weaker stories before. Though some may debate that.
I'm told that a UK comics publisher will be publishing a Harry Potter comic book strip to run between the 6th and 7th book. It's meant to look like an old Tiger-style comic book and it will be published a month before the 7th novel.
If so, that's the biggest selling comic of 2007 already in the bag."