The law would have to acknowledge that the supernatural exists to have a code for them, so no, there isn't. There are only the rules enforced by hunters, which, admittedly, can make us pretty bad, too. If we're not careful about targeting only the ones that are actually asking for it. But I don't think there's going to be any better way of doing it, not in my world anyway, anytime soon. This world has figured it out a little better, since the existence of the supernatural (and alien) is more publicly known.
I don't think there's a cure for me, although there is something in my future that might be... purifying. What would happen if you were cured? Would you be dead, or alive again?