The star was diagnosed with the disease in the latter half of 2023 but only revealed the news in November 2024.

Among those who reacted to Van Der Beek's death was his Dawson's Creek co-star Busy Philipps, who played a university roommate of Joey Potter, portrayed by Katie Holmes.

In a post on Instagram, Philipps wrote: "James Van Der Beek was one in a billion and he will be forever missed and I don't know what else to say. I am just so so sad. He was my friend and I loved him and I'm so grateful for our friendship all these years."

She urged her 2.4m followers to help out his family through the online fundraiser that they had set up to help with medical bills and other expenses.

The GoFundMe page posted online on Wednesday solicited donations to assist Van Der Beek's widow Kimberley and their six children, whose ages range from four to 15.

"I am profoundly heartbroken for his incredible wife Kimberly and their six magical children," Philipps said, sharing photos from their time on the teen drama, which aired between 1998 and 2003.

Mary-Margaret Humes, who played Van Der Beek's mother on Dawson's Creek shared an Instagram tribute in honour of her late co-star on Wednesday.

"Rarely am I at a loss for words ... today would be the exception. James, my gracious warrior, you fought a hard battle against all odds with such quiet strength and dignity," she wrote alongside two photos of them together.

"I will always love and admire you for that. Our last conversations ... merely a few days ago ... are forever sitting softly in my heart for safe keeping. To our extended Dawson's Creek family of friends, please be respectful of our silences at the moment as Beautiful Kimberly and family have asked for peaceful privacy for now."

Philipps and Van Der Beek reunited onscreen in 2012 for an episode of the ABC comedy Don't Trust the B---- in Apartment 23, in which Van Der Beek played a fictionalised version of himself.

Actress Krysten Ritter, Van Der Beek's co-star in Don't Trust the B---- in Apartment 23, remembered him as a "beautiful human inside and out".

Ritter wrote on Instagram: "Smart, funny, empathic, kind, talented and just pure magic. I'm so grateful for our friendship and so heartbroken. All my love goes out to his amazing wife Kimberly and their children."

"Love you so much James and fake James," she added.

While Van Der Beek was set to reunite with his Dawson's Creek co-stars - including Oscar winner Michelle Williams, Katie Holmes and Joshua Jackson last September - the actor could only make a video appearance due to his illness.

Hamilton and In the Heights creator Lin-Manuel Miranda, who stepped in for Van Der Beek at the event, paid tribute to the actor on Instagram, writing that his "whole heart" is with Van Der Beek's family.

Actor and TV presenter Alfonso Ribeiro shared on Instagram that he got to say goodbye to his "true friend, brother and life guide" over the weekend, writing that he will always cherish his role as godfather to Van Der Beek's daughter Gwen and now sees Van Der Beek as his guardian angel.

"I was with him through this horrible journey to beat cancer. His family and friends went on this roller coaster ride. The highs when it looked like he had it beat to the breaking lows of it coming back," the Fresh Prince of Bel-Air alum wrote.

Retired wrestler and cheerleader Stacy Keibler shared a photo of herself and Van Der Beek taking in a sunset as the actor was seated in a wheelchair.

She said that she too got to spend Van Der Beek's final days with him.

"When you know time is sacred, you don't waste a single breath. You don't rush. You don't scroll. You don't worry about tomorrow. You sit. You listen. You hold hands. You watch the sky change colors and you let it change you too.

"In these past days, you taught me more about being present than any book ever could. You showed me what it looks like to trust God's plan, even when it breaks your heart. Especially when it breaks your heart," she wrote.

Actor Chad Michael Murray, who appeared in Dawson's Creek and One Tree Hill, described Van Der Beek as "a giant".

"His words, art and humanity inspired all of us - he inspired us to be better in all ways. God bless you guys," he wrote in the comments section of the family's Instagram post announcing his death.

"I'm so grateful for being able to call James a brother. I'll miss him deeply. Rest easy," added Kerr Smith, who starred alongside Van Der Beek in Dawson's Creek.

"James represented something to aspire to," wrote One Tree Hill actor Austin Nichols, who also appeared in Varsity Blues.

"As a friend, husband and father, I know he was even more powerful and inspiring. You will be missed," Nichols said.

Commenting on the family's Instagram announcement, Buffy the Vampire Slayer star Sarah Michelle Gellar wrote that she is "so sad for your beautiful family".

"While James legacy will always live on, this is a huge loss to not just your family but the world," the actress wrote.

Actress Jennifer Garner described Van Der Beek's death as a "heartbreaking loss" and sent love to his widow and children as they "navigate this tender time".