UPDATE: Will Ferrell is not pursuing a film project about President Ronald Reagan, a spokesman for the actor said Friday, according to the Associated Press. The actor had read and considered the script for "Reagan" but had never committed to developing or starring in the comedic film, which had prompted a strong family backlash.

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Ronald Reagan's daughter, Patti Davis, took Will Ferrell to task over recent news that he'll produce and star in a comedy about her father's years suffering from Alzheimer's.

In an open letter published in the Daily Beast on Thursday, Davis blasted Ferrell for making light of the disease and her family's suffering.

"Perhaps you have managed to retain some ignorance about Alzheimer's and other versions of dementia," she wrote. "Perhaps if you knew more, you would not find the subject humorous."

Also Read: Will Ferrell to Play Ronald Reagan in Alzheimer's Comedy 'Reagan'

As TheWrap previously reported, Ferrell is set to play the president in the political satire "Reagan," written by Mike Rosolio. The film, whose script was voted to the 2015 Black List of Hollywood's best unproduced screenplays, follows the commander-in-chief as he succumbs to dementia and is convinced by an ambitious intern that he's actually an actor playing the president in a movie.

Davis detailed some of the suffering her family endured while her father succumbed to Alzheimer's, which she describes as the "ultimate pirate" that "steals what is most precious to a human being — memories, connections, the familiar landmarks of a lifetime that we all come to rely on to hold our place secure in this world and keep us linked to those we have come to know and love."

Also Read: Will Ferrell, Mark Wahlberg to Star in 'Daddy's Home 2'

"I watched as fear invaded my father's eyes–this man who was never afraid of anything. I heard his voice tremble as he stood in the living room and said, 'I don't know where I am,'" she wrote. "There was laughter in those years, but there was never humor."

She challenged Ferrell to visit facilities that care for dementia patients and face families of those who suffer from Alzheimer's, daring him to find something humorous about the disease.

Also Read: Will Ferrell to Star in, Produce Action Comedy for Universal

"The only certainty with Alzheimer's is that more will be lost and the disease will always win in the end," she wrote. "Perhaps you would like to explain to them how this disease is suitable material for a comedy."