Dosing, duration, and timing controversies in determining immune checkpoint inhibitor dosing regimens

It is often advocated that immune checkpoint inhibitors (ICIs) are overdosed and that lower doses, shorter treatment durations, and decreased administration frequencies can be safely applied irrespective of individual and indication. We argue that ICI dosing regimens should, comparably to vaccines against infectious diseases, be predominantly based on immune activation level, meaning that lower doses, shorter treatment durations, and less frequent administrations, cannot be safely applied according to a “one-size-fits-all” approach as is currently gaining traction. In this manuscript, we discuss existing ICI dosing, duration, and timing controversies supporting this view. Furthermore, we propose future strategies that could be used to develop more “personalized” ICI dosing regimens that may lead to higher treatment efficacy.