Another producer purchased the rights after Garcia’s death, and he attempted to make the movie for years before too much time had passed and he lost the film rights.
Interestingly, various producers have looked into producing Sirens of Titan for the big screen over the years.
Now, it seems likely that we’ll never get a film version of Sirens of Titan.
Jerry Garcia of The Grateful Dead back in the 1980s was the first to buy the film rights of the book from Kurt Vonnegut, but he passed away before he could actually make the movie.