So I'm not really quite sure what Landis' plans were to make another one. The American Werewolf in Paris was a completely separate story.
Clearly any film company that makes a film is always going to talk about sequels particularly if they see something as being successful, which Werewolf was.
I've done both theatre and film and the fact is if you start believing, if you start reading things and they're good reviews - you believe that and you're lost, and then you read bad reviews and you think that's true and you read that and you're lost.