From page 206 of the Monster Manual:
A remove curse spell can rid an afflicted lycanthrope of the curse, but a natural born lycanthrope can be freed of the curse only with a wish.
As a strict reading this could mean that only Remove Curse would work to cure someone who wasn't born a lycanthrope. However most spells that inflict a curse also state that magic similar to, or more powerful than, Remove Curse also work so I think any reasonable DM would allow any spell that can lift a curse to work as well - such a spell being Greater Restoration.
But that's just what the books say. A DM has free rein to create their own cures if they see fit, which could be the basis for an entire quest. As Erik suggested in the comments, in older editions eating Belladonna would cure lycanthropy but it was toxic so there was a risk to taking that route. Maybe there's a potion made from rare ingredients that could cure it. The possibilities are left up to the DM's imagination.