James Van Der Beek is backing out of a "Dawson's Creek" reunion amid his battle with cancer.

The actor, who played the eponymous Dawson for six seasons of the popular teen drama, announced in an Instagram post Sunday, Sept. 21, that he would not be in attendance for a charity event set to bring together the original cast for a table reading of the pilot's script. He cited stomach viruses as the reason for his cancellation.

"This is the evening I'd been looking forward to MOST since my angel Michelle Williams said she was putting it together, way back in January," Van Der Beek wrote in the post. Williams also starred in "Dawson's Creek."

"So you can imagine how gutted I was when two stomach viruses conspired to knock me out of commission and keep me grounded at the worst possible moment," he wrote.

"Despite every effort… I won't get to be there," his post continued. "I won't get to stand on that stage and thank every soul in the theater for showing up for me, and against cancer, when I needed it most." The actor, 48, was diagnosed with colorectal cancer in August 2023.

Van Der Beek assured audiences, however, that the show, slated for Sept. 22, would go on as planned with noted playwright and actor Lin-Manuel Miranda taking his place.

"I DO have an understudy," he wrote. "A ridiculously overqualified replacement who would have been #1 on my wishlist (had I ever dreamed he'd be available). Someone my kids would definitely consider an upgrade over me… Plus, he already knows how to get to the theater. So that’s convenient. The role of 'Dawson,' usually played by James Van Der Beek…Will be played by Lin-Manuel Miranda," he revealed.

"Can't believe I just got to type that," he continued. "Everyone please enjoy all the love in that room. Shine some on my family. I will be beaming and receiving from afar in a bed in Austin. And thank you @lin_manuel . You were a hero to my kids before… now you're a demigod "

Van Der Beek, who went public with his diagnosis in November, told USA TODAY in December that the outpouring of love from his friends, including former "Dawson's" castmates, had been overwhelming.

"It's been amazing and overwhelming," he said. "To find myself in a place where I'm being supported with so many good wishes really took me aback."

And in August, Van Der Beek revealed to USA TODAY that cancer hadn't just prompted gestures of love from others, it had forced him to lean in to self-love.

"Cancer's a wild thing," he said. "It really does force you to look at your own mortality and decide what's important and decide really what you want to live the rest of your life without. And so, one of the big things for me was recognizing how negative my self-talk was."

Contributing: Bryan Alexander, Charles Trepany

This article originally appeared on USA TODAY: James Van Der Beek abruptly drops out of 'Dawson's Creek' reunion, citing illness

Reporting by Anna Kaufman, USA TODAY / USA TODAY

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