'The Big C' Adds Kathy Najimy, Isaac Mizrahi for Final Season

Kathy Najimy Isaac Mizrahi Split - H 2012
Courtesy of Showtime

Kathy Najimy Isaac Mizrahi Split - H 2012

The Big C is adding a pair for its final season.

The final run of Showtime's cancer dramedy has enlisted Kathy Najimy and Isaac Mizrahi for its fourth and final season, Showtime announced Thursday.

STORY: Showtime Renews 'The Big C' for Fourth, Final Season of Four Hourlong Episodes

The final season, dubbed a four-part limited-event series, will see the Laura Linney starrer wrap its run with Najimy appearing in all four episodes as Cathy's no-nonsense therapist who will help her deal with the challenges she faces now that her cancer has returned.

PHOTOS: THR's Cover Shoot With the Stars of Showtime

Mizrahi will appear in multiple episodes as himself and serve as a fashion mentor to Gabourey Sidibe, who will begin design school when the fourth season returns.

“It has been a true joy watching someone as gifted as Laura Linney take Cathy Jamison on her journey these past three seasons,” Showtime Entertainment president David Nevins said in making the announcement. “We wanted to take particular care to honor the fans of the show with a compelling and memorable conclusion. We thank Laura, Jenny Bicks, Darlene Hunt and The Big C’s gifted ensemble of actors, producers and crew for the remarkable work they have created.”

STORY: 'The Big C' Postmortem: EP Talks Freedom, Season 4 Plans

Returning for the fourth season of the Hunt-created series are Linney, Oliver Platt, John Benjamin Hickey, Gabriel Basso and Sidibe. A premiere date has not yet been announced.

"The next stage of grief is depression, and it leads to acceptance; how we would play with those we have a good sense of, but the fourth season would not entirely be depression," Bicks told The Hollywood Reporter following the season-three finale. "We are going to move through depression fairly quickly. You're not going to necessarily see these things so literally."

Email: Lesley.Goldberg@thr.com; Twitter: @Snoodit