ABC Family will air an all-day The Secret Life Of The American Teenager marathon March 18 ahead of the season premiere at 8 PM. The network said in October that it wasn’t renewing the series beyond the current season, which is set for a final 12 episodes. The drama from 7th Heaven creator Brenda Hampton was the breakout hit that put ABC Family on the scripted map when it premiered in June 2008, helping to launch several of the network’s next generation of series and making a star out of lead Shailene Woodley, who went on to land the co-lead opposite George Clooney in The Descendants, a role that earned her an Independent Spirit Award and Golden Globe nomination last year. Season 5 of the show premiered in June when 11 episode ran.