Objective response rate assessment in oncology: Current situation and future expectations

Table 5 Immune response criteria[63-66]

	irRC (2D), 2009	irRECIST (1D), 2013	iRECIST (1D), 2017	imRECIST (1D), 2018
Minimum number of target lesions	10 lesions in total; 5 lesions per organ	5 lesions in total; 2 lesions per organ	5 lesions in total; 2 lesions per organ	5 lesions in total; 2 lesions per organ
New lesions	Included in the sum of the measurements	Included in the sum of the measurements	iUPD; becomes iCPD if PD eventually confirmed	Included in the sum of the measurements
CR	Disappearance of all lesions	Disappearance of all lesions	Disappearance of all lesions	Disappearance of all lesions
PR	≥ 50% decrease from baseline	≥ 30% decrease from baseline	≥ 30% decrease from baseline	≥ 30% decrease from baseline
SD	Neither CR nor PD	Neither CR nor PD	Neither CR nor PD	Neither CR nor PD
PD	≥ 25% increase in the nadir	≥ 20% increase in the nadir (minimum 5 mm)	≥ 20% increase in the nadir (minimum 5 mm)	≥ 20% increase in the nadir (minimum 5 mm)
Confirmation of PD	Yes	Yes1	Yes2	Yes3

¹At least 4 wk after, and up to 12 wk;

²At least 4 wk after, and up to 8 wk;

³4 wk after. 1D: Unidimensional; 2D: Bidimensional; CR: Complete response; PR: Partial response; SD: Stable disease; PD: Progressive disease; iUPD: Immune unconfirmed progressive disease; iCPD: Immune confirmed progressive disease; irRECIST: İmmune-related Response Evaluation Criteria in Solid Tumors; iRECIST: İmmunotherapy Response Evaluation Criteria in Solid Tumors; irRC: İmmune-specific related response criteria; imRECIST: Immune-Modified Response Evaluation Criteria In Solid Tumors.