Table 1

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

Resistance phenotypeDrug exposure requirementBest responseConfirmatory scan for PD requirementConfirmatory scan time frame
Primary resistanceA minimum of 2 cycles of both drugs (6–12 weeks)PD, SD < 6 monthsYes, if clinically stableAt least 4 weeks after PD, if clinically feasible

  • ICIs, immune checkpoint inhibitors; PD, progressive disease; SD, stable disease.