The Big Bang Theory star Kaley Cuoco has said she is "drowning in tears" over the news that the global comedy hit will end in 2019.

On Wednesday, show creator and executive producer Chuck Lorre announced that the 12th season, which begins in the US next month, would be the last.

Cuoco, who has played Penny since The Big Bang Theory began in 2007, said that despite her sadness, the show would go "out with a bang" in its final season.

Writing on Instagram, Cuoco said: "This ride has been a dream come true and as life changing as it gets. No matter when it was going to end, my heart would have always been broken in two. Drowning in tears, we promise to bring you the best season yet." 

Cuoco concluded: "To the fans, our crew, families, Chuck Lorre, Warner Brothers, CBS, and everyone who has supported us for so many years, thank you. We are goin out with a bang."