Hi Ryan,
sure there is possibility to modify a backlog query(as any other saved search attributes) in left sidebar > "Saved searches" panel on issues list. Find your project's backlog saved search and click on 'edit' under the small triangle on the left. The query can be modified in the opened "Edit 'A backlog' saved search" dialog.
Note, logged in user has to have the appropriate permissions to edit this saved search.
Look at the doc reference for details -
http://confluence.jetbrains.com/display/YTD4/Quick+Start+Guide.+Using+Saved+SearchesPlease look/comment the
http://youtrack.jetbrains.com/issue/JT-4310