The developer behind Sleeping Dogs has been closed. The decision was made during the early access window of their newest title, SMASH+GRAB, which is now no longer available for purchase on Steam.
The studio was founded in 2007, and is also known for their work on ModNation Racers and LittleBigPlanet Karting. The in-universe sequel to Sleeping Dogs, the online open-world Triad Wars, was shut down in January and cancelled.
For my money, Sleeping Dogs was far more enjoyable than any Grand Theft Auto game, and I hope the developers find work as soon as possible.