Marvel's editor-in-chief said that the series will be recognisably different to the great many Avengers titles already published by the company.
"I've been pushing for a new Defenders book for a while," Alonso told Comic Book Resources. "We [Marvel] see the potential of building a team with a strong mission statement that could anchor a franchise."
The series will be penned by Fear Itself scribe Matt Fraction with artwork from Terry Dodson, and will boast an impressive cast including Namor, Red She-Hulk, Iron Fist, Silver Surfer and Doctor Strange.
"What we needed was a writer with a killer high concept - we found that with Matt - and a launching pad - we found that in the post Fear Itself landscape, loose strands from that story that the Defenders could deal with," Alonso explained. "The Defenders are not the Avengers. They're called 'The Defenders' for a reason and you'll see why immediately."
Alonso said the Defenders will become an important "force" in the Marvel Universe with a "rock solid mission statement".
He also revealed that The Defenders will see regular guest appearances from characters across the Marvel pantheon.
"While the team has a core group, there'll be lots of opportunities for some cool guest stars that fit more easily into the Defenders roster and mandate than, say, an Avengers story," he promised.
The Defenders #1 will be published this December.