In December 2013, Sony announced two spin-offs of The Amazing Spider-Man franchise, The Sinister Six and Venom, with Drew Goddard attached to write and direct The Sinister Six. At the end of The Amazing Spider-Man 2, a line-up/set-up of the team was foreshadowed throughout the film and during the end credits: Rhino, Vulture, Doctor Octopus, Mysterio, and Kraven the Hunter were all teased as the members, with the Green Goblin serving as the leader (however, the line-up is left in debate as Goddard stated he wanted to adapt a more classic adaptation of the group which would have included Sandman and Doc Ock as the leader). The film was said to be a redemption story for the characters, and would probably not feature Spider-Man. As the Sinister Six's original goal, however, was to kill him, there would seem to be a chance that he would appear. The film was originally scheduled for release on November 11, 2016. However, after the announcement in February 2015 of a new Spider-Man franchise with Marvel Studios, the spin-offs were postponed and eventually cancelled.
In July 2017, following the collaboration between Marvel Studios and Sony Pictures, a different film featuring the Sinister Six was announced to be in development. The team was teased in the mid-credits scene of Spider-Man: Homecoming, showing Adrian Toomes in prison where he is told by Mac Gargan that he's got some "boys on the outside". In an email leaked by the Sony Pictures hack, Pascal revealed that she planned for Tom Holland's Spider-Man to appear in a Sinister Six film set in the Marvel Cinematic Universe, depending on the success of the then-upcoming licensing agreement with Marvel Studios. In October 2018, Goddard acknowledge that his script could eventually be reworked for the film. By December of the same year, producer Amy Pascal confirmed that the studio intends to use the script in the upcoming project and expressed the company's desire for Goddard to direct the film as well.