Amid low ratings, “I Am Cait,” E’s documentary series chronicling Caitlyn Jenner’s life as a transgender woman, is finished after two seasons.

Ms. Jenner announced the news on Twitter on Tuesday, saying after two seasons that “it’s time for the next adventure.”

“I Am Cait” premiered last July to enormous expectations following Ms. Jenner’s April 2015 revelation that she was transgender. Every step Ms. Jenner took last spring resulted in a ratings bonanza, including an ABC interview with Diane Sawyer and an appearance at ESPN’s ESPY award ceremony.

But those massive ratings never materialized for her E! series. The premiere of the show debuted to a respectable 2.7 million viewers but it declined significantly from there. The second season premiere debuted to just 750,000 viewers.