Three people, including the gunman, were killed in the shooting on Thursday night, leaving seven others injured.
"One of the reasons we make these movies is because the world can be so horrifying and we all need to laugh just to deal with it," Apatow said in a statement.
"So to have this happen in a room where people were smiling and laughing devastates me. My thoughts and love go out to the victims and anyone touched by this madness or any madness. We, as a country, need to find a way to do better," he said.
"All of us at Universal Pictures send our heartfelt sympathies to the victims of this senseless tragedy and their families in Louisiana," the studio said.
The Academy of Motion Picture Arts and Sciences released a statement on Friday, saying, "The movie-going experience is one we should be able to enjoy in a safe environment with family and friends. Our thoughts and prayers are with the loved ones of the victims and their families.