In The Eyre Affair, one of the minor characters works in the department which investigates undead and similar activities. He is a lycanthrope, but he can avoid an attack if he takes his medication.
In the Computer Game Gaberial Knight: the Beast Withen(which had a system as well defined, if not moreso, then most movies), if one was born a werewolf, they could never become human, but as long as they never tasted of human blood, would remain chained to the mortal plane(or limbo) upon death. Not great, but better then the alternative(Hell).
One who is cursed to become a werewolf must have the curse removed or be chained to the mortal plane upon death.
The system used invovled Alpha werwolves and Beta Werewolves. The Alpha has the original tainted blood(Curse,Birth) and a Beta is anyone that the Alpha bites, or one of the beta with the same taint bites.
If one becomes a werewolf through bite, then they must kill the Alpha werewolf who carried the original taint. The Alpha, however, cannot kill any betas, or will die himself.
Oh,and in any case, tasting human blood as a wolf condemns you to hell when you die, as well as never being able to become normal again. The upside of this, werewolves can only be killed by a fatal blow to the heart or the brain.
I suspect the main reason there are no cures for lycanthropy is because it’s seen as a more primal expression of Evil. Instead of being some sort of demonic gift, an exchange of slavery to blood for immortality, it is the intrusion of the most basic animal instincts on a formerly human spirit. You cannot change a wild animal such as the wolf; you must kill it, exterminate it, chase it back into the dark lair from whence it came. The vampire, on the other hand, retains its human soul, but is burdened by the weight of its bloody curse–and so removing that burden can release the soul again.
I wrote a short play about a werewolf some years ago, and thoroughly researched the matter of a cure at the time.
I don’t remember much of it, but I do remember finding documentation of a cure, which had to be administered before the February full moon or the victim would become a wolf fulltime.
google isn’t helping me now, but maybe that’s a starting point for someone else.