APM Cookbook: AutoLaunch SAML Resources
If you setup SAML SLO (SAML Single LogOut) then it will log the user out of the APM. As an alternative, you can have the SAML SP send a logged out user to your apm with the URL https://myapmvirtualserver.ccompany.com/vdesk/hangup.php3 and the session will be terminated. Or you could just leave the APM session in place and redirect a logged out user to something else like your website.
If you have auto-login through something like NTLM or Kerberos, then when the user is logged out they may just get logged back in automatically depending on which method above is used, so in that case you might want to write an iRule that intercepts and redirects the user somewhere else after a logout or perhaps anytime the incoming referer header is the logout page of the app, that way they won't just go to /my.policy and then get sent along to the app again.