In fact, it has something called Thrust Control Malfunction Protection.
Yes, I'm very familiar with "TCMA" - although not all 777s have it, only the GE90-110B/115B. TCMA doesn't exist on the earlier GE90 or Pratt/Rolls powered 777s. It is however basic on all the newer models - 787 (both engines) and 747-8 - and both the 737Max and 777X will have TCMA.
It's not really there for ground runs (though it would still be of benefit if an engine ran away uncontrolled) - it's there for takeoff or landing where an uncontrollable high thrust event could result in a high speed runway departure.