Last October, FOX cancelled animated sitcom Murder Police, which had been given a 13-episode order, before a single episode was aired. In that case, no completed episodes had been completed, only scripts and rough footage from several episodes.
A few days ago the network did it again, announcing it would not air the seven completed episodes of sitcom Us & Them. The series, an adaption of the 2007-2010 British series Gavin & Stacey, starred Jason Ritter and Alexis Bledel. FOX ordered 13 episodes in May 2013 and like Murder Police intended to use the series as a mid-season replacement during the 2013-2014 season.
Right around the time Murder Police was cancelled, FOX halted production on Us & Them, effectively cancelling that series as well. But the completed episodes were supposedly going to be burnt of this summer. Now, TV Line and Vulture are both reporting that FOX has announced it will not be airing the episodes after all.
Over the past 20-25 years it has become increasingly common for networks to cancel shows they’re not happy with before they premiere, with multiple episodes in the can. Prior to the 1990s, on the other hand, it was incredibly rare. You can read about four examples from the 1960s through the 1980s in my article Programs Cancelled Before They Premiered, 1963-1988.