Buy the Alien: Isolation Season Pass and get five add on packs as they become available to download. All Season Pass content will be available by March 2015. If you purchase the Alien: Isolation Season Pass, all future content that is part of this pass will be accessible in-game once it is available.
Content included

Alien: Isolation - Corporate Lockdown
Alien: Isolation - Trauma
Alien: Isolation - Safe Haven
Alien: Isolation - Lost Contact
Alien: Isolation - The Trigger