United Kingdom, Oct. 13 -- Shonda Rhimes doesn't know how Grey's Anatomy will end.

The 55-year-old screenwriter has served as the show's executive producer since 2005 - but Shonda still doesn't know how the long-running TV show will conclude.

During an appearance on the Today show, Shonda explained: "To be at 450 [episodes] is amazing, and really all because of the fans and the fact that they've kept watching the show and they've stuck with it and they're excited and invested."

Shonda has been inundated with questions about the show's long-term future over recent years. But the acclaimed screenwriter doesn't know what the future holds.

She shared: "I'd say back at around episode 150, I knew how it was going to end. Now we're at 450, I...