In an earnings call today CD Projekt Red had confirmed that most of their 600 developers have moved onto working on The Witcher 4, codenamed Polaris.
With over 400 developers working on the next Witcher game, it is clear that they are full steam ahead on the next iteration of the franchise and it is the game furthest along in development at the company.
While not much Is known about the game, we know it is the beginning of a new trilogy set in the Witcher world. Though we shouldn't expect to see the game anytime soon, in 2022 CD said it would be at least 3 years away, meaning the earliest we could see it is 2025.

Also during the call CD revealed 47 employees are at work on the next Cyberpunk game, though the game is still in pre-production.
Will you be returning to the world of the Witcher when Polaris releases?