Brandon Blackstock, a talent manager who was the ex-husband of Kelly Clarkson and the former stepson of Reba McEntire, has died.

“It is with great sadness that we share the news that Brandon Blackstock has passed away,” a rep for his family told PEOPLE in a statement. “Brandon bravely battled cancer for more than three years. He passed away peacefully and was surrounded by family. We thank you for your thoughts and prayers and ask everyone to respect the family’s privacy during this very difficult time.”

Blackstock was 48.

On Wednesday, Clarkson announced that Blackstock had been unwell, prompting her to postpone her Las Vegas residency to focus on their children, River, 11, and Remington, 9.

“While I normally keep my personal life private, this past year, my children’s father has been

See Full Page