Even though the script was definitely different, they were able to get Christopher Plumber, Bruce Willis, Brad Pitt, and Madeleine Stowe to star in it. The movie ended up winning awards and Brad Pitt was nominated for an Oscar for Best Supporting Actor and he won a Golden Globe Award.
The movie is called: Twelve Monkeys, and although it's about 25 years old, it's still worth watching because the storyline is so creative. It's not the type movie that you can step away from for a moment, too much is going on so you should remain focused to get the most out of the movie.
If you haven't seen the film and you like Sci-Fi's, you should check it out. If you saw it a long time ago, you should see it again. Although the movie hasn't changed, inevitably you have. :)