I don't think that Slaughterhouse-Five was successful movie material. In fact, Vonnegut's books mostly I don't feel are movie material.
“I was planning on my future as a homeless person. I had a really good spot picked out.”
“It's amazing how fast generations lose sight of other generations. One of the first things the young composers who come to work with me say is that they want to write music people will like, instead of gaining their credentials by being rejected by the audience.”