It will be produced by Steven Moffat, Brian Minchin, and Patrick Ness, an acclaimed young adult author who will also be writing the series.
Following news of the Orlando shooting, Ness took to Twitter to reveal that the spinoff would have a lead character who was LGBT - something they were planning on keeping secret, until the shooting happened.
The writer was inundated with responses, many of which were people thanking him for the representation of LGBT in such a popular franchise.
While Ness gracefully accepted the thanks, he was "kind of astounded" it was such a big deal, and hoped that one day it wouldn't be.
He was also quick to add: "There's way more than one character on the show, of course; lots of stories to be told. With aliens and terror and emotions and stuff.
"So I can't wait for you to meet the characters of Class, all of em, all their sorrows and joys and goofiness and loves and losses."
The series has been pitched as following students dealing with "friends, love, sex, parents, school, and the occasional alien monster hell-bent on destroying Earth".
It will star Katherine Kelly (Mr. Selfridge, Happy Valley) as the mysterious teacher Miss Quill, and the main foursome of young alien fighters will be played by Greg Austin, Fady Elsayed, Sophie Hopkins, and Vivian Oparah.
