临床试验终点指标详解：ORR、PFS与OS

The co-primary endpoints of this study were the confirmed ORR, PFS, and OS as assessed by IRC. ORR is defined as the proportion of participants who achieved complete response (CR) or partial response (PR) after treatment. PFS is defined as the time from randomization to the first documentation of tumor progression or death from any cause. Disease progression and response assessment are evaluated by IRC according to RECIST 1.1 criteria. OS is defined as the time from randomization to death from any cause. Secondary endpoints include investigator-assessed ORR and PFS, DCR and DoR as assessed by both investigator and IRC, and safety. DCR is defined as the proportion of participants who achieved CR, PR, or stable disease (SD) after treatment. DoR is defined as the time from the first documentation of objective response to the first documentation of tumor progression or death from any cause. Safety assessments are based on the CTCAE 5.0 criteria for severity, with AESIs including bowel obstruction and interstitial lung disease. Exploratory endpoints include the correlation between EGFR protein expression levels (assessed by IHC in a qualified central laboratory) and efficacy endpoints, as well as investigator-assessed ORR, DCR, and DoR in the control group that crossed over to receive MRG003 treatment. EGFR expression levels are defined as follows: negative: no target staining; 1+: 1%-25% target staining; 2+: 26%-50% target staining; 3+: 51%-75% target staining; 4+: >75% target staining.