A mad doctor’s experiments cause an outbreak of of cannibalism at an insane asylum.
It does take a very long while to get going, but once it does, how appealing you find that one-sentence synopsis will pretty much tell you how much you will like the movie.
I will say, within the range of what movies that could be summarized as “a mad doctor’s experiments cause an outbreak of of cannibalism at an insane asylum” could possibly be, this is pretty much near the top. The doctor is played by Peter Stormare, if that tells you anything.