EXCLUSIVE: James McAvoy Drops Out Of Untitled Cancer Comedy, Joseph Gordon-Levitt Replaces Him

Last August, James McAvoy signed on to star in the formerly titled "I'm With Cancer," a comedy co-starring Seth Rogen about a 25-year-old battling cancer. MTV News has exclusively learned that McAvoy has dropped out of the film after shooting began and that he has been replaced with Joseph Gordon-Levitt.

A source close to the production tells us that McAvoy dropped out this week for personal reasons and that producers have locked Gordon-Levitt to step into the role. Shooting on the film, which began last month in Vancouver, has temporarily ceased and will resume the week of March 8. MTV has reached out to Summit Entertainment, and they've now confirmed the casting move.

Rogen said in a statement: "It’s incredibly unfortunate that circumstances outside of everyone’s control have taken James away from the project, but, with James’s blessing, we were able to have Joseph step in to take on the [lead] role of Adam. We all look forward to working with James in the future."

McAvoy's role as the cancer-stricken twentysomething had been touted as the actor's first high-profile one following the success of 2008's "Wanted." The film is based on the true experiences of screenwriter Will Reiser, who successfully waged his own battle with cancer in his 20s. Rogen is producing with his writing partner Evan Goldberg. The movie co-stars Anna Kendrick and Bryce Dallas Howard.

"'I'm with Cancer' is a very personal story, about what happened to our friend for the most part," Rogen told MTV News last summer. "So we didn’t really need much added insight into that. I was there with [Reiser] as he experienced a lot of it."