I think Viva Forever suffered from the fact the Spice Girls didn't have enough songs to justify a stage musical and the story was not as strong compared to Mamma Mia! Hannah John Kamen came out unscathed as she has starred in three major Hollywood films this year and Tamara Wall ended up in Hollyoaks.
Here's a quick rundown, using similar criteria to the classic book 'Not Since Carrie' on Broadway flops. Under 250 performances, not a limited run, not been on Broadway, not a revue or compilation show, not a revival. As with that book there are probably a few missed and I've added a few that would have fallen outside that limitation. Some may have been time limited runs but would surely have extended or transferred if successful.
I chose Bernadette as the starting point because that really has to be the nadir of West End musicals in living memory. I can add a list of ones from before if needed!
Over sixty shows and I managed to see over three quarters of them.....
1990 Bernadette Heaven’s Up King Someone Like You
1991 Children of Eden Hunting of the Snark Matador
1992 From a Jack to a King Moby Dick Radio Times Valentine’s Day Which Witch
1993 Leonardo: Portrait of Love Lust c.1461 Robin, Prince of Sherwood
1994 Out of the Blue
1995 Prisoner Cell Block H
1997 Always Fields of Ambrosia Stepping Out Maddie
1998 Saucy Jack & the Space Vixens
1999 A Saint She Ain’t Boyband Casper – the Musical Tess of the D’Urbevilles
2000 La Cava Lautrec Hard Times Napoleon
2001 Closer to Heaven (off West End) Peggy Sue Got Married
2003 Money to Burn (off West End)
2004 The Beautiful & the Damned The Big Life Murderous Instincts Oscar Wilde (off West End)
2005 Acorn Antiques The Far Pavilions The Man in the Iron Mask
2006 Daddy Cool
2007 Bad Girls – the Musical Desperately Seeking Susan
2008 Gone With the Wind The Harder They Come Imagine This Marguerite Never Forget
2009 Too Close to the Sun
2010 All the Fun of the Fair Flashdance Love Story
2011 Backbeat Betty Blue Eyes Lend me a Tenor Umbrellas of Cherbourg
2013 From Here to Eternity Stephen Ward Viva Forever