Table 2

Drug exposure and best response requirements for secondary resistance to ICI combinations

Resistance phenotypeDrug exposure requirementBest responseConfirmatory scan for PD requirementConfirmatory scan time frame
Secondary resistance*>6 monthsCR, PR, or SD
≥6 months†
Yes, if clinically stableAt least 4 weeks after PD, if clinically feasible
  • *For ICI combinations administered as induction dosing (ie, one agent is dropped after a set number of cycles) secondary resistance is defined for the monotherapy that was continued.

  • †For aggressive tumors such as mesothelioma and NSCLC, 3 months is required.

  • CR, complete response; ICI, immune checkpoint inhibitor; NSCLC, non-small cell lung cancer; PD, progressive disease; PR, partial response; SD, stable disease.