Finneran, who was previously seen on the situation comedy "I Hate My Teenage Daughter," will play Fox's "narcissistic, single and jobless sister," according to Deadline.com.
The series, a single-camera comedy, will debut in the fall; it is inspired by Fox's struggle with Parkinson's disease. The cast will also feature Conor Romero and Jack Gore.
The currently untitled comedy, according to Deadline.com, casts Fox as "Mike Burnaby, a husband and father of three in New York City juggling the challenges of family and career while dealing with Parkinson’s disease. A former lead anchor for a local station in NY, Mike decides to go back to work after a new medication helps him manage the effects of his illness."