Welcome @pickle7, My only experience is with PMR. I'm wondering if @marilyncarkner, @paddington and @tsc may have some thoughts on continuing or discontinuing treatment with Actemra. I did find some information on the topic that may be worth discussing with your doctor if you want to discontinue the treatment and your GCA is under control.

Nearly Half of Giant Cell Arteritis Patients on Actemra for a Year Stay in Remission After Stopping It: https://creakyjoints.org/treatment/tocilizumab-actemra-giant-cell-arteritis-prolonged-remission/

Are you on any other treatment along with the Actemra and are your GCA symptoms gone?