Table 2.

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

Resistance phenotype	Drug exposure requirement	Best response	Confirmatory scan for PD requirement	Confirmatory scan time frame
Secondary resistance*	>6 months	CR, PR, or SD ≥6 months†	Yes, if clinically stable	At 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.