Proof, the smash Pulitzer Prize-winning Broadway play, will lose its current cast, led by Jennifer Jason Leigh, June 30, when their contracts are up.

A spokesman confirmed producers are seeking a new cast, likely to include a marquee-value name along the lines of the production's Leigh and Mary Louise Parker. The latter originated the role of Catherine, a young woman who may or may not have inherited the genius — and the sickness — of her father. Parker took home a Tony for her work.

Playwright Auburn won the 2001 Best Play Tony Award and the 2001 Pulitzer Prize for Proof, which originated at Manhattan Theatre Club. Director Daniel Sullivan picked up a Best Director Tony last year, as well. The work is, at turns, a drama about family dysfunction, a comedy, a romance and a mystery.

A hit national tour starring Robert Foxworth in the father role and Chelsea Altman as Catherine ends in late June, shortly before the current Broadway troupe (Seana Kofoed, Josh Hamilton and Patrick Tovatt) says goodbye to the Walter Kerr Theatre.

A new Broadway company would likely be in rehearsal for three weeks prior to an expected July 2 start. The play is already starting to boom as an attraction in regional theatres and is expected to be one of the most-produced works by resident American companies in coming seasons. Auburn himself staged a production at Coconut Grove Playhouse in Miami earlier this year. The week ending May 5, Proof played to 45.97 percent of capacity at the Kerr.

Gwyneth Paltrow is the star of the London staging and has been announced as the lead in a film version of the show.

Jennifer Jason Leigh stepped into the role of Catherine on Broadway Sept. 14, 2001. The play opened Off-Broadway May 23, 2000 to wide critical acclaim, and played a sold-out, extended run at Manhattan Theatre Club's Stage I. It opened on Broadway Oct. 24, 2000.

Producers are Manhattan Theatre Club, Roger Berlind, Carole Shorenstein, Jujamcyn Theatres, Ostar Enterprises, Inc., Daryl Roth, Stuart Thompson Productions.