Cynthia will appear alongside John Hurt as he reprises his role of Quentin Crisp in the follow-up to the classic 70s drama The Naked Civil Servant.
The show – which sees the outspoken Quentin move to Manhattan and become a darling of the New York social scene – has begun shooting on location in the cosmopolitan capital.
Native New Yorker Cynthia will play Penny Arcade the performance artist and playwright who befriended Quentin in his latter years.
Together they created long-running performance/interview piece, The Last Will And Testament Of Quentin Crisp.
James Burstall, executive producer, said: “Choosing to shoot the film in New York was a risky decision as the drama industry works very differently in the US from the UK. But the huge amount of strategic planning and the leap of faith are delivering a first rate calibre of cast.
“There is a real buzz about the project in Manhattan as Quentin was a much-loved and notorious figure – everyone has an anecdote to tell about him.
“And we’ve been touched by the number of friends and admirers of his (some of whom he never knew) who have wanted to help with the project in a myriad different ways.”
Also joining the cast is Brothers and Sisters actor Denis O’Hare, who will play magazine editor Phillip Steele, and Pushing Daisies’ Swoozie Kurtz as Quentin’s American agent Connie Clausen.