SSO ADFS redirect to application server

Hi,
I have a sharepoint 2010 intranet site (web front end server) which is under ADFS sso. There is an application server that hosts a mvc3 application. The front end web server has an proxy web application inside IIS sharepoint site (just a web.config file inside the virtual folder) which does a url re-write to the application server's mvc3 application. This works fine, when WINDOWS USERS access the sharepoint site (http://intranet) and can access the mvc3 application (http://intranet/mvc3app) from the web server. Also the ADFS users can get to the sharepoint intranet site. 
Question: The ADFS users cannot access the MVC3 app. I  need to get access to the mvc3 application in the application server for the ADFS users.. We CANNOT do another SSO configuration for the mvc application to access or make it claim aware app. I can pass the saml token info thro ...