There is not a direct option inside of the sequence to set up 'conditional sending', however, between the tag feature in the sequence, and our SmartList concept, you can set up workflows that follow those types of logic.
In order to do this, you need to (a) have a tag applied to the records as a sequence step after the emails go out (Call it a 'Check Opens' tag), and (b) create a SmartList with 2 filter parameters, (1) Tag is 'Check Opens' and (2) Number of Total Email Opens equals 0.
Once this SmartList is created, add this to the Auto-Unenrollment options for the Sequence, and it will auto-unenroll if those conditions are met!