A Saint She Ain't, the new musical comedy which premiered in April at the fringe King's Head Theatre, transfers to the West End next month. It will open at the Apollo Theatre, Shaftesbury Avenue, on Wednesday 22 September (previews from 16 September).

Loosely based on Le Cocu Imaginaire by Moliere, A Saint She Ain't is a pastiche of Hollywood film musicals of the 1940s. Each character is based on a real-life film star such as WC Fields, Mae West, Rita Hayworth and Gene Kelly. A comedy of errors, the story follows two young lovers who, through a series of events and hearsay, believe the other to be unfaithful.

The principals from the original King's Head six-week sell-out run return for the West End debut. Writer and TV game show star Barry Cryer heads the cast which also includes Rae Baker, Gavin Lee, Pauline Daniels, Brian Greene, Vincent Marzello and Michael Roberts.

A Saint She Ain't has book and lyrics by Dick Vosburgh and music by Denis King, who have teamed up on several other West End musicals including Stepping Out - The Musical, Poppy and Windy City.

The new musical is directed by raconteur and broadcaster Ned Sherrin, whose production of Keith Waterhouse's Jeffrey Bernard is Unwell, starring Peter O'Toole, opens this week at the Old Vic. Musical direction is by Chris Walker and Denis King, design by Paul Farnsworth and choreography by Lindsay Dolan.

Rob Becker's Defending the Caveman, starring Mark Little, is currently playing at the Apollo. It finishes its run on 11 September.