It basically serves as an insurance policy to me in case things go awry in patients.
What are you insuring against, exactly? If you pull the switch and thereby deactivate the immunotherapy, the patient will presumably die from the underlying disease. (It’s not realistic to think that such a patient could be switched to a different curative therapy.)
“The efficient-market hypothesis may be the foremost piece of B.S. ever promulgated in any area of human knowledge!”