Acclaimed actor Michael Sheen and actress Lizzy Caplan have been cast as the leads in the SHOWTIME drama pilot MASTERS OF SEX, where they will portray 1960's human sexuality pioneers William Masters and Virginia Johnson. Directed by Academy Award® nominee John Madden ("Shakespeare in Love"), the pilot will begin production in New York in March. Michelle Ashford (THE PACIFIC), Judith Verno, and Sarah Timberman and Carl Beverly (JUSTIFIED) are executive producers. Michael Sheen and Tammy Rosen will serve as producers. MASTERS OF SEX is produced by Sony Pictures Television.